Foster, Katherine T; Arterberry, Brooke J; Iacono, William G; McGue, Matt; Hicks, Brian M
In the United States, cannabis accessibility has continued to rise as the perception of its harmfulness has decreased. Only about 30% of regular cannabis users develop cannabis use disorder (CUD), but it is unclear if individuals who use cannabis regularly without ever developing CUD experience notable psychosocial impairment across the lifespan. Therefore, psychosocial functioning was compared across regular cannabis users with or without CUD and a non-user control group during adolescence (age 17; early risk) and young adulthood (ages 18-25; peak CUD prevalence). Weekly cannabis users with CUD (n = 311), weekly users without CUD (n = 111), and non-users (n = 996) were identified in the Minnesota Twin Family Study. Groups were compared on alcohol and illicit drug use, psychiatric problems, personality, and social functioning at age 17 and from ages 18 to 25. Self-reported cannabis use and problem use were independently verified using co-twin informant report. In both adolescence and young adulthood, non-CUD users reported significantly higher levels of substance use problems and externalizing behaviors than non-users, but lower levels than CUD users. High agreement between self- and co-twin informant reports confirmed the validity of self-reported cannabis use problems. Even in the absence of CUD, regular cannabis use was associated with psychosocial impairment in adolescence and young adulthood. However, regular users with CUD endorsed especially high psychiatric comorbidity and psychosocial impairment. The need for early prevention and intervention - regardless of CUD status - was highlighted by the presence of these patterns in adolescence.
Scott, Laura A; Roxburgh, Amanda; Bruno, Raimondo; Matthews, Allison; Burns, Lucy
Residual effects of ecstasy use induce neurotransmitter changes that make it biologically plausible that extended use of the drug may induce psychological distress. However, there has been only mixed support for this in the literature. The presence of polysubstance use is a confounding factor. The aim of this study was to investigate whether regular cannabis and/or regular methamphetamine use confers additional risk of poor mental health and high levels of psychological distress, beyond regular ecstasy use alone. Three years of data from a yearly, cross-sectional, quantitative survey of Australian regular ecstasy users was examined. Participants were divided into four groups according to whether they regularly (at least monthly) used ecstasy only (n=936), ecstasy and weekly cannabis (n=697), ecstasy and weekly methamphetamine (n=108) or ecstasy, weekly cannabis and weekly methamphetamine (n=180). Self-reported mental health problems and Kessler Psychological Distress Scale (K10) were examined. Approximately one-fifth of participants self-reported at least one mental health problem, most commonly depression and anxiety. The addition of regular cannabis and/or methamphetamine use substantially increases the likelihood of self-reported mental health problems, particularly with regard to paranoia, over regular ecstasy use alone. Regular cannabis use remained significantly associated with self reported mental health problems even when other differences between groups were accounted for. Regular cannabis and methamphetamine use was also associated with earlier initiation to ecstasy use. These findings suggest that patterns of drug use can help identify at risk groups that could benefit from targeted approaches in education and interventions. Given that early initiation to substance use was more common in those with regular cannabis and methamphetamine use and given that this group had a higher likelihood of mental health problems, work around delaying onset of initiation
Chanteloup, Francoise; Lenton, Simon; Fetherston, James; Barratt, Monica J
The effect on the cannabis market is one area of interest in the evaluation of the new 'prohibition with civil penalties' scheme for minor cannabis offences in WA. One goal of the scheme is to reduce the proportion of cannabis consumed that is supplied by large-scale suppliers that may also supply other drugs. As part of the pre-change phase of the evaluation, 100 regular (at least weekly) cannabis users were given a qualitative and quantitative interview covering knowledge and attitudes towards cannabis law, personal cannabis use, market factors, experience with the justice system and impact of legislative change. Some 85% of those who commented identified the changes as having little impact on their cannabis use. Some 89% of the 70 who intended to cultivate cannabis once the CIN scheme was introduced suggested they would grow cannabis within the two non-hydroponic plant-limit eligible for an infringement notice under the new law. Only 15% believed an increase in self-supply would undermine the large scale suppliers of cannabis in the market and allow some cannabis users to distance themselves from its unsavoury aspects. Only 11% said they would enter, or re-enter, the cannabis market as sellers as a result of the scheme introduction. Most respondents who commented believed that the impact of the legislative changes on the cannabis market would be negligible. The extent to which this happens will be addressed in the post-change phase of this research. Part of the challenge in assessing the impact of the CIN scheme on the cannabis market is that it is distinctly heterogeneous.
Meier, Madeline H.; Caspi, Avshalom; Ambler, Antony; Harrington, HonaLee; Houts, Renate; Keefe, Richard S. E.; McDonald, Kay; Ward, Aimee; Poulton, Richie; Moffitt, Terrie E.
Recent reports show that fewer adolescents believe that regular cannabis use is harmful to health. Concomitantly, adolescents are initiating cannabis use at younger ages, and more adolescents are using cannabis on a daily basis. The purpose of the present study was to test the association between persistent cannabis use and neuropsychological decline and determine whether decline is concentrated among adolescent-onset cannabis users. Participants were members of the Dunedin Study, a prospecti...
Bloomfield, Michael A P; Morgan, Celia J A; Egerton, Alice; Kapur, Shitij; Curran, H Valerie; Howes, Oliver D
Cannabis is the most widely used illicit drug globally, and users are at increased risk of mental illnesses including psychotic disorders such as schizophrenia. Substance dependence and schizophrenia are both associated with dopaminergic dysfunction. It has been proposed, although never directly tested, that the link between cannabis use and schizophrenia is mediated by altered dopaminergic function. We compared dopamine synthesis capacity in 19 regular cannabis users who experienced psychotic-like symptoms when they consumed cannabis with 19 nonuser sex- and age-matched control subjects. Dopamine synthesis capacity (indexed as the influx rate constant [Formula: see text] ) was measured with positron emission tomography and 3,4-dihydroxy-6-[(18)F]-fluoro-l-phenylalanine ([(18)F]-DOPA). Cannabis users had reduced dopamine synthesis capacity in the striatum (effect size: .85; t36 = 2.54, p = .016) and its associative (effect size: .85; t36 = 2.54, p = .015) and limbic subdivisions (effect size: .74; t36 = 2.23, p = .032) compared with control subjects. The group difference in dopamine synthesis capacity in cannabis users compared with control subjects was driven by those users meeting cannabis abuse or dependence criteria. Dopamine synthesis capacity was negatively associated with higher levels of cannabis use (r = -.77, p < .001) and positively associated with age of onset of cannabis use (r = .51, p = .027) but was not associated with cannabis-induced psychotic-like symptoms (r = .32, p = .19). These findings indicate that chronic cannabis use is associated with reduced dopamine synthesis capacity and question the hypothesis that cannabis increases the risk of psychotic disorders by inducing the same dopaminergic alterations seen in schizophrenia. Copyright © 2014 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.
Bonn-Miller, Marcel O; Boden, Matthew Tyler; Bucossi, Meggan M; Babson, Kimberly A
Little research has investigated the demographic and symptom profile of medical cannabis users in states in the USA that have legalized cannabis use. In the present cross-sectional study, we investigated the demographic profile of 217 adults currently receiving medical cannabis, as well as differences in problematic use and perceived helpfulness in terms of (i) symptoms of psychological disorders and pain, and (ii) motives for use. Findings indicated that medical cannabis users (i) use and perceive cannabis to be beneficial for multiple conditions, some for which cannabis is not specifically prescribed or allowed at the state level; and (ii) report similar rates of disordered use as compared with population estimates among regular users. Furthermore, problematic cannabis use was predicted by several symptoms of psychological disorders (e.g. depression) and a variety of use motives (e.g. coping), while cannabis was reported as particularly helpful among those with several psychological symptoms (e.g. traumatic intrusions), as well as those reporting use for social anxiety reasons. Results are discussed in terms of future directions for research given the current debates regarding legalization of cannabis for medical purposes and, more generally, the lack of empirical data to inform such debates.
Full Text Available Abstract Cannabis smoking can create respiratory problems. Vaporizers heat cannabis to release active cannabinoids, but remain cool enough to avoid the smoke and toxins associated with combustion. Vaporized cannabis should create fewer respiratory symptoms than smoked cannabis. We examined self-reported respiratory symptoms in participants who ranged in cigarette and cannabis use. Data from a large Internet sample revealed that the use of a vaporizer predicted fewer respiratory symptoms even when age, sex, cigarette smoking, and amount of cannabis used were taken into account. Age, sex, cigarettes, and amount of cannabis also had significant effects. The number of cigarettes smoked and amount of cannabis used interacted to create worse respiratory problems. A significant interaction revealed that the impact of a vaporizer was larger as the amount of cannabis used increased. These data suggest that the safety of cannabis can increase with the use of a vaporizer. Regular users of joints, blunts, pipes, and water pipes might decrease respiratory symptoms by switching to a vaporizer
Rachel Melissa Burns
Full Text Available Collecting information about the prevalence of cannabis use is necessary but not sufficient for understanding the size, dynamics, and outcomes associated with cannabis markets. This paper uses two data sets describing cannabis consumption in the United States and Europe to highlight 1 differences in inferences about sub-populations based on the measure used to quantify cannabis-related activity; 2 how different measures of cannabis-related activity can be used to more accurately describe trends in cannabis usage over time; and 3 the correlation between frequency of use in the past month and average grams consumed per day. Key findings: Focusing on days of use instead of prevalence shows substantially greater increases in U.S. cannabis use in recent years; however, the recent increase is mostly among adults, not youth. Relatively more rapid growth in use days also occurred among the college-educated and Hispanic. Further, data from a survey conducted in several European countries show a strong positive correlation between frequency of use and quantity consumed per day of use, suggesting consumption is even more skewed toward the minority of heavy users than is suggested by days-of-use calculations.
Mikael A Kowal
Full Text Available Chronic cannabis use has been shown to block long-term depression of GABA-glutamate synapses in the striatum, which is likely to reduce the extent to which endogenous cannabinoids modulate GABA- and glutamate-related neuronal activity. The current study aimed at investigating the effect of this process on striatal dopamine levels by studying the spontaneous eye blink rate (EBR, a clinical marker of dopamine level in the striatum. 25 adult regular cannabis users and 25 non-user controls matched for age, gender, race, and IQ were compared. Results show a significant reduction in EBR in chronic users as compared to non-users, suggesting an indirect detrimental effect of chronic cannabis use on striatal dopaminergic functioning. Additionally, EBR correlated negatively with years of cannabis exposure, monthly peak cannabis consumption, and lifetime cannabis consumption, pointing to a relationship between the degree of impairment of striatal dopaminergic transmission and cannabis consumption history.
Cuttler, Carrie; Spradlin, Alexander; Nusbaum, Amy T; Whitney, Paul; Hinson, John M; McLaughlin, Ryan J
One of the most commonly cited reasons for chronic cannabis use is to cope with stress. Consistent with this, cannabis users have shown reduced emotional arousal and dampened stress reactivity in response to negative imagery. To our knowledge, the present study represents the first to examine the effects of an acute stress manipulation on subjective stress and salivary cortisol in chronic cannabis users compared to non-users. Forty cannabis users and 42 non-users were randomly assigned to complete either the stress or no stress conditions of the Maastricht Acute Stress Test (MAST). The stress condition of the MAST manipulates both physiological (placing hand in ice bath) and psychosocial stress (performing math under conditions of social evaluation). Participants gave baseline subjective stress ratings before, during, and after the stress manipulation. Cortisol was measured from saliva samples obtained before and after the stress manipulation. Further, cannabis cravings and symptoms of withdrawal were measured. Subjective stress ratings and cortisol levels were significantly higher in non-users in the stress condition relative to non-users in the no stress condition. In contrast, cannabis users demonstrated blunted stress reactivity; specifically, they showed no increase in cortisol and a significantly smaller increase in subjective stress ratings. The stress manipulation had no impact on cannabis users' self-reported cravings or withdrawal symptoms. Chronic cannabis use is associated with blunted stress reactivity. Future research is needed to determine whether this helps to confer resiliency or vulnerability to stress-related psychopathology as well as the mechanisms underlying this effect.
Full Text Available Cognitive biases, including implicit memory associations are thought to play an important role in the development of addictive behaviors. The aim of the present study was to investigate implicit affective memory associations in heavy cannabis users. Implicit positive-arousal, sedation, and negative associations towards cannabis were measured with three Single Category Implicit Association Tests (SC-IAT’s and compared between 59 heavy cannabis users and 89 controls. Moreover, we investigated the relationship between these implicit affective associations and explicit expectancies, subjective craving, cannabis use, and cannabis related problems. Results show that heavy cannabis users had stronger implicit positive-arousal associations but weaker implicit negative associations towards cannabis compared to controls. Moreover, heavy cannabis users had stronger sedation but weaker negative explicit expectancies towards cannabis compared to controls. Within heavy cannabis users, more cannabis use was associated with stronger implicit negative associations whereas more cannabis use related problems was associated with stronger explicit negative expectancies, decreasing the overall difference on negative associations between cannabis users and controls. No other associations were observed between implicit associations, explicit expectancies, measures of cannabis use, cannabis use related problems, or subjective craving. These findings indicate that, in contrast to other substances of abuse like alcohol and tobacco, the relationship between implicit associations and cannabis use appears to be weak in heavy cannabis users.
Full Text Available The long-term effects of cannabis on human cognition are still unclear, but, considering that cannabis is a widely used substance and, overall, its potential use in therapeutic interventions, it is important to evaluate them. We hypothesize that the discrepancies among studies could be attributed to the specific cognitive function investigated and that skills subserved by the hippocampus, such as the spatial orientation abilities and, specifically, the ability to form and use cognitive maps, should be more compromised than others. Indeed it has been showed that cannabis users have a reduced hippocampus and that the hippocampus is the brain region in which cannabis has the greatest effect since it contains the highest concentration of cannabinoid receptors. To test this hypothesis we asked 15 heavy cannabis users and 19 nonusers to perform a virtual navigational test, the CMT, that assesses the ability to form and use cognitive maps. We found that using cannabis has no effect on these hippocampus-dependent orientation skills. We discuss the implications of our findings and how they relate to evidence reported in the literature that the intervention of functional reorganization mechanisms in cannabis user allows them to cope with the cognitive demands of navigational tasks.
Cousijn, Janna; Goudriaan, Anna E.; Wiers, Reinout W.
Aims Repeated drug exposure can lead to an approach-bias, i.e. the relatively automatically triggered tendencies to approach rather that avoid drug-related stimuli. Our main aim was to study this approach-bias in heavy cannabis users with the newly developed cannabis Approach Avoidance Task
Indrajeet Sharma; Tulika Jha; Purshottam K. Kaundal
Background: Cannabis is the world's most commonly used illicit drug, with approximately 200 to 300 million regular users. It occupies fourth place in worldwide popularity among psychoactive drugs, after caffeine, nicotine and alcohol. Nowadays, cannabis is widely used by young people and, the prevalence of lifetime use of cannabis by young adults has increased in many developed countries over the past several decades. Methods: It was a one year cross-sectional observational study. The stu...
Looby, Alison; Earleywine, Mitch
Abstract Background Cannabis is the most widely consumed illicit substance in America, with increasing rates of use. Some theorists tend to link frequency of use with cannabis dependence. Nevertheless, fewer than half of daily cannabis users meet DSM-IV-TR criteria for cannabis dependence. This study seeks to determine whether the negative aspects associated with cannabis use can be explained by a proxy measure of dependence instead of by frequency of use. Results Over 2500 adult daily cannab...
Hesse, Morten; Tutenges, Sébastien
Background In most western countries, the most prevalent type of illicit substance-use dependence in most is cannabis dependence. Historically, cannabis has been associated with several music genres, and the drug is widely used at music festivals. Methods Based on a survey of 380 music festival...... guests, we estimated the prevalence of cannabis dependence, as defined by a score of 3 or more on the Severity of Dependence Scale, as well as festival goers' use of cannabis during the past year. Results 143 (38%) reported having used cannabis within the past year (past year cannabis users......), and of these respondents, 21 (15%) screened positive for cannabis dependence. Compared to non-dependent cannabis users, the cannabis dependent respondents were more likely to be daily smokers, they reported having attended fewer music festivals during their lifetime, and they scored higher on self-reported sensation...
Macatee, Richard J; Okey, Sarah A; Albanese, Brian J; Schmidt, Norman B; Cougle, Jesse R
Prevalence of cannabis use is increasing, but many regular users do not develop cannabis use disorder (CUD); thus, CUD risk identification among current users is vital for targeted intervention development. Existing data suggest that high distress intolerance (DI), an individual difference reflective of the ability to tolerate negative affect, may be linked to CUD, but no studies have tested possible neurophysiological mechanisms. Increased motivated attentional processing of cannabis and negative emotional stimuli as indexed by neurophysiology [i.e. the late positive potential (LPP)], particularly during acute stress, may contribute to CUD among high DI users. Frequent cannabis users with high (n = 61) and low DI (n = 44) viewed cannabis, negative, and matched neutral images during electroencephalography (EEG) recording before and after a laboratory stressor. Cannabis cue-elicited modulation of the 1000- to 3000-milliseconds LPP was larger in high DI users at post-stressor only, although the effect was only robust in the 1000- to 2000-milliseconds window. Further, modulation magnitude in the high DI group covaried with stress-relief craving and some CUD indices in the 400- to 1000-milliseconds and 1000- to 3000-milliseconds windows, respectively. No significant effects of DI on negative stimuli-elicited LPP modulation were found, although inverse associations with some CUD indices were observed. Finally, exploratory analyses revealed some evidence for DI moderation of the relation between subjective stressor reactivity and negative stimuli-elicited LPP modulation such that greater stressor reactivity was associated with blunted versus enhanced modulation in the high and low DI groups, respectively. Negative and cannabis stimuli-elicited LPP modulation appear to index distinct, CUD-relevant neural processes in high DI cannabis users. © 2018 Society for the Study of Addiction.
Hartung, Benno; Schwender, Holger; Roth, Eckhard H; Hellen, Florence; Mindiashvili, Nona; Rickert, Annette; Ritz-Timme, Stefanie; Grieser, Almut; Monticelli, Fabio; Daldrup, Thomas
To assess the effects of cannabis on the ability required to ride a bicycle, repetitive practical cycling tests and medical examinations were carried out before and after inhalative consumption of cannabis. A maximum of three joints with body weight-adapted THC content (300 μg THC per kg body weight) could be consumed by each test subject. Fourteen regular cannabis-consuming test subjects were studied (12 males, 2 females). In summary, only a few driving faults were observed even under the influence of very high THC concentrations. A defined THC concentration that leads to an inability to ride a bicycle cannot be presented. The test subjects showed only slight distinctive features that can be documented using a medical test routinely run for persons under suspicion of driving under the influence of alcohol or drugs.
Chye, Yann; Suo, Chao; Yücel, Murat; den Ouden, Lauren; Solowij, Nadia; Lorenzetti, Valentina
Cannabis use is associated with neuroanatomical alterations in the hippocampus. While the hippocampus is composed of multiple subregions, their differential vulnerability to cannabis dependence remains unknown. The objective of the study is to investigate gray matter alteration in each of the hippocampal subregions (presubiculum, subiculum, cornu ammonis (CA) subfields CA1-4, and dentate gyrus (DG)) as associated with cannabis use and dependence. A total of 35 healthy controls (HC), 22 non-dependent (CB-nondep), and 39 dependent (CB-dep) cannabis users were recruited. We investigated group differences in hippocampal subregion volumes between HC, CB-nondep, and CB-dep users. We further explored the association between CB use variables (age of onset of regular use, monthly use, lifetime use) and hippocampal subregions in CB-nondep and CB-dep users separately. The CA1, CA2/3, CA4/DG, as well as total hippocampal gray matter were reduced in volume in CB-dep but not in CB-nondep users, relative to HC. The right CA2/3 and CA4/DG volumes were also negatively associated with lifetime cannabis use in CB-dep users. Our results suggest a regionally and dependence-specific influence of cannabis use on the hippocampus. Hippocampal alteration in cannabis users was specific to the CA and DG regions and confined to dependent users.
Full Text Available This review summarizes the available literature on the intersection of adolescent cannabis use and sleep disturbances, along with interventions for adolescent cannabis users who suffer sleep impairments. Adolescents are susceptible to various sleep disorders, which are often exacerbated by the use of substances such as cannabis. The relationship between cannabis and sleep is bidirectional. Interventions to improve sleep impairments among adolescent cannabis users to date have demonstrated limited efficacy, although few studies indicating the benefits of behavioral interventions—such as Cognitive Behavior Therapy for Insomnia or Mindfulness Based Stress Reduction—appear promising in the treatment of sleep disorders, which are present for users of cannabis. Further research is necessary to elucidate the precise mechanisms by which cannabis use coexists with sleep impairments, along with effective interventions for those users who suffer sleep difficulties.
Solowij, Nadia; Jones, Katy A; Rozman, Megan E; Davis, Sasha M; Ciarrochi, Joseph; Heaven, Patrick C L; Lubman, Dan I; Yücel, Murat
Long-term heavy cannabis use can result in memory impairment. Adolescent users may be especially vulnerable to the adverse neurocognitive effects of cannabis. In a cross-sectional and prospective neuropsychological study of 181 adolescents aged 16-20 (mean 18.3 years), we compared performance indices from one of the most widely used measures of learning and memory--the Rey Auditory Verbal Learning Test--between cannabis users (n=52; mean 2.4 years of use, 14 days/month, median abstinence 20.3 h), alcohol users (n=67) and non-user controls (n=62) matched for age, education and premorbid intellectual ability (assessed prospectively), and alcohol consumption for cannabis and alcohol users. Cannabis users performed significantly worse than alcohol users and non-users on all performance indices. They recalled significantly fewer words overall (pmemory performance after controlling for extent of exposure to cannabis. Despite relatively brief exposure, adolescent cannabis users relative to their age-matched counterparts demonstrated similar memory deficits to those reported in adult long-term heavy users. The results indicate that cannabis adversely affects the developing brain and reinforce concerns regarding the impact of early exposure.
Full Text Available Abstract Background Cannabis is the most widely consumed illicit substance in America, with increasing rates of use. Some theorists tend to link frequency of use with cannabis dependence. Nevertheless, fewer than half of daily cannabis users meet DSM-IV-TR criteria for cannabis dependence. This study seeks to determine whether the negative aspects associated with cannabis use can be explained by a proxy measure of dependence instead of by frequency of use. Results Over 2500 adult daily cannabis users completed an Internet survey consisting of measures of cannabis and other drug use, in addition to measures of commonly reported negative problems resulting from cannabis use. We compared those who met a proxy measure of DSM-IV-TR criteria for cannabis dependence (N = 1111 to those who did not meet the criteria (N = 1770. Cannabis dependent subjects consumed greater amounts of cannabis, alcohol, and a variety of other drugs. They also had lower levels of motivation, happiness, and satisfaction with life, with higher levels of depression and respiratory symptoms. Conclusion Although all of our subjects reported daily use, only those meeting proxy criteria for cannabis dependence reported significant associated problems. Our data suggest that dependence need not arise from daily use, but consuming larger amounts of cannabis and other drugs undoubtedly increases problems.
Lau, Nicholas; Sales, Paloma; Averill, Sheigla; Murphy, Fiona; Sato, Sye-Ok; Murphy, Sheigla
Cannabis use is becoming more accepted in mainstream society. In this paper, we use Zinberg's classic theoretical framework of drug, set, and setting to elucidate how older adult cannabis users managed health, social and legal risks in a context of normalized cannabis use. We present selected findings from our qualitative study of Baby Boomer (born 1946-1964) cannabis users in the San Francisco Bay Area. Data collection consisted of a recorded, in-depth life history interview followed by a questionnaire and health survey. Qualitative interviews were analyzed to discover the factors of cannabis harm reduction from the users' perspectives. Interviewees made harm reduction choices based on preferred cannabis derivatives and routes of administration, as well as why, when, where, and with whom to use. Most interviewees minimized cannabis-related harms so they could maintain social functioning in their everyday lives. Responsible and controlled use was described as moderation of quantity and frequency of cannabis used, using in appropriate settings, and respect for non-users. Users contributed to the normalization of cannabis use through normification. Participants followed rituals or cultural practices, characterized by sanctions that helped define "normal" or "acceptable" cannabis use. Users contributed to cannabis normalization through their harm reduction methods. These cultural practices may prove to be more effective than formal legal prohibitions in reducing cannabis-related harms. Findings also suggest that users with access to a regulated market (medical cannabis dispensaries) were better equipped to practice harm reduction. More research is needed on both cannabis culture and alternative routes of administration as harm reduction methods. Copyright © 2015 Elsevier B.V. All rights reserved.
Belendiuk, Katherine A; Babson, Kimberly A; Vandrey, Ryan; Bonn-Miller, Marcel O
Individuals report using cannabis for the promotion of sleep, and the effects of cannabis on sleep may vary by cannabis species. Little research has documented preferences for particular cannabis types or cannabinoid concentrations as a function of use for sleep disturbances. 163 adults purchasing medical cannabis for a physical or mental health condition at a cannabis dispensary were recruited. They provided self-report of (a) whether cannabis use was intended to help with sleep problems (e.g. insomnia, nightmares), (b) sleep quality (PSQI), (c) cannabis use (including preferred type), and (d) symptoms of DSM-5 cannabis dependence. 81 participants reported using cannabis for the management of insomnia and 14 participants reported using cannabis to reduce nightmares. Individuals using cannabis to manage nightmares preferred sativa to indica strains (Fisher's exact test (2) = 6.83, p < 0.05), and sativa users were less likely to endorse DSM-5 cannabis dependence compared with those who preferred indica strains (χ(2)(2) = 4.09, p < 0.05). Individuals with current insomnia (t(9) = 3.30, p < 0.01) and greater sleep latency (F(3,6) = 46.7, p < 0.001) were more likely to report using strains of cannabis with significantly higher concentrations of CBD. Individuals who reported at least weekly use of hypnotic medications used cannabis with lower THC concentrations compared to those who used sleep medications less frequently than weekly (t(17) = 2.40, p < 0.05). Associations between sleep characteristics and the type of cannabis used were observed in this convenience sample of individuals using cannabis for the management of sleep disturbances. Controlled prospective studies are needed to better characterize the impact that specific components of cannabis have on sleep. Copyright © 2015. Published by Elsevier Ltd.
Lau, Nicholas; Sales, Paloma; Averill, Sheigla; Murphy, Fiona; Sato, Sye-Ok; Murphy, Sheigla
Background Cannabis use is becoming more accepted in mainstream society. In this paper, we use Zinberg’s classic theoretical framework of drug, set, and setting to elucidate how older adult cannabis users managed health, social and legal risks in a context of normalized cannabis use. Methods We present selected findings from our qualitative study of Baby Boomer (born 1946–1964) cannabis users in the San Francisco Bay Area. Data collection consisted of a recorded, in-depth life history interview followed by a questionnaire and health survey. Qualitative interviews were analyzed to discover the factors of cannabis harm reduction from the users’ perspectives. Results Interviewees made harm reduction choices based on preferred cannabis derivatives and routes of administration, as well as why, when, where, and with whom to use. Most interviewees minimized cannabis-related harms so they could maintain social functioning in their everyday lives. Responsible and controlled use was described as moderation of quantity and frequency of cannabis used, using in appropriate settings, and respect for non-users. Users contributed to the normalization of cannabis use through normification. Conclusion Participants followed rituals or cultural practices, characterized by sanctions that helped define “normal” or “acceptable” cannabis use. Users contributed to cannabis normalization through their harm reduction methods. These cultural practices may prove to be more effective than formal legal prohibitions in reducing cannabis-related harms. Findings also suggest that users with access to a regulated market (medical cannabis dispensaries) were better equipped to practice harm reduction. More research is needed on both cannabis culture and alternative routes of administration as harm reduction methods. PMID:25911027
Koenders, L; Lorenzetti, V; de Haan, L; Suo, C; Vingerhoets, Wam; van den Brink, W; Wiers, R W; Meijer, C J; Machielsen, Mwj; Goudriaan, A E; Veltman, D J; Yücel, M; Cousijn, J
Cannabis exposure, particularly heavy cannabis use, has been associated with neuroanatomical alterations in regions rich with cannabinoid receptors such as the hippocampus in some but not in other (mainly cross-sectional) studies. However, it remains unclear whether continued heavy cannabis use alters hippocampal volume, and whether an earlier age of onset and/or a higher dosage exacerbate these changes. Twenty heavy cannabis users (mean age 21 years, range 18-24 years) and 23 matched non-cannabis using healthy controls were submitted to a comprehensive psychological assessment and magnetic resonance imaging scan at baseline and at follow-up (average of 39 months post-baseline; standard deviation=2.4). Cannabis users started smoking around 16 years and smoked on average five days per week. A novel aspect of the current study is that hippocampal volume estimates were obtained from manual tracing the hippocampus on T1-weighted anatomical magnetic resonance imaging scans, using a previously validated protocol. Compared to controls, cannabis users did not show hippocampal volume alterations at either baseline or follow-up. Hippocampal volumes increased over time in both cannabis users and controls, following similar trajectories of increase. Cannabis dose and age of onset of cannabis use did not affect hippocampal volumes. Continued heavy cannabis use did not affect hippocampal neuroanatomical changes in early adulthood. This contrasts with prior evidence on alterations in this region in samples of older adult cannabis users. In young adults using cannabis at this level, cannabis use may not be heavy enough to affect hippocampal neuroanatomy.
Lee, Dustin C.; Crosier, Benjamin S.; Borodovsky, Jacob T.; Sargent, James D.; Budney, Alan J.
Background Along with changes in cannabis laws in the United States and other countries, new products for consuming cannabis are emerging, with unclear public health implications. Vaporizing or “vaping” cannabis is gaining popularity, but little is known about its prevalence or consequences. Methods This study characterized the prevalence and current patterns of vaping cannabis among a large national sample of cannabis users. An online survey was distributed through Facebook ads targeting individuals with interests related to cannabis use. The sample comprised 2,910 cannabis users (age: 18-90, 84% male, 74% Caucasian). Results A majority (61%) endorsed lifetime prevalence of ever vaping, 37% reported vaping in the past 30 days, 20% reported vaping more than 100 lifetime days, and 12% endorsed vaping as their preferred method. Compared to those that had never vaped, vaporizer users were younger, more likely to be male, initiated cannabis at an earlier age, and were less likely to be African American. Those that preferred vaping reported it to be healthier, better tasting, produced better effects, and more satisfying. Only 14% reported a reduction in smoking cannabis since initiating vaping, and only 5% mixed cannabis with nicotine in a vaporizer. Many cannabis users report vaping cannabis, but currently only a small subset prefers vaping to smoking and reports frequent vaping. Conclusion Increases in availability and marketing of vaping devices, and the changing legal status of cannabis in the United States and other countries may influence patterns of use. Frequent monitoring is needed to assess the impact of changing cannabis laws and regulations. PMID:26774946
Lee, Dustin C; Crosier, Benjamin S; Borodovsky, Jacob T; Sargent, James D; Budney, Alan J
Along with changes in cannabis laws in the United States and other countries, new products for consuming cannabis are emerging, with unclear public health implications. Vaporizing or "vaping" cannabis is gaining popularity, but little is known about its prevalence or consequences. This study characterized the prevalence and current patterns of vaping cannabis among a large national sample of cannabis users. An online survey was distributed through Facebook ads targeting individuals with interests related to cannabis use. The sample comprised 2910 cannabis users (age: 18-90, 84% male, 74% Caucasian). A majority (61%) endorsed lifetime prevalence of ever vaping, 37% reported vaping in the past 30 days, 20% reported vaping more than 100 lifetime days, and 12% endorsed vaping as their preferred method. Compared to those that had never vaped, vaporizer users were younger, more likely to be male, initiated cannabis at an earlier age, and were less likely to be African American. Those that preferred vaping reported it to be healthier, better tasting, produced better effects, and more satisfying. Only 14% reported a reduction in smoking cannabis since initiating vaping, and only 5% mixed cannabis with nicotine in a vaporizer. Many cannabis users report vaping cannabis, but currently only a small subset prefers vaping to smoking and reports frequent vaping. Increases in availability and marketing of vaping devices, and the changing legal status of cannabis in the United States and other countries may influence patterns of use. Frequent monitoring is needed to assess the impact of changing cannabis laws and regulations. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
Cuttler, Carrie; Mischley, Laurie K.; Sexton, Michelle
Abstract Introduction: Despite known sex differences in the endocannabinoid system of animals, little attention has been paid to sex differences in human's cannabis use patterns and effects. The purpose of the present study was to examine sex differences in cannabis use patterns and effects in a large sample of recreational and medical cannabis users. Methods: A large sample (n=2374) of cannabis users completed an anonymous, online survey that assessed their cannabis use practices and experiences, including the short-term acute effects of cannabis and withdrawal effects. A subsample of 1418 medical cannabis users further indicated the medical conditions for which they use cannabis and its perceived efficacy. Results: The results indicated that men reported using cannabis more frequently and in higher quantities than did women. Men were more likely to report using joints/blunts, vaporizers, and concentrates, while women were more likely to report using pipes and oral administration. Men were more likely than women to report increased appetite, improved memory, enthusiasm, altered time perception, and increased musicality when high, while women were more likely than men to report loss of appetite and desire to clean when high. Men were more likely than women to report insomnia and vivid dreams during periods of withdrawal, while women were more likely than men to report nausea and anxiety as withdrawal symptoms. Sex differences in the conditions for which medical cannabis is used, and its efficacy, were trivial. Conclusions: These results may be used to focus research on biological and psychosocial mechanisms underlying cannabis-related sex differences, to inform clinicians treating individuals with cannabis use disorders, and to inform cannabis consumers, clinicians, and policymakers about the risks and benefits of cannabis for both sexes. PMID:28861492
Cuttler, Carrie; Mischley, Laurie K; Sexton, Michelle
Introduction: Despite known sex differences in the endocannabinoid system of animals, little attention has been paid to sex differences in human's cannabis use patterns and effects. The purpose of the present study was to examine sex differences in cannabis use patterns and effects in a large sample of recreational and medical cannabis users. Methods: A large sample ( n =2374) of cannabis users completed an anonymous, online survey that assessed their cannabis use practices and experiences, including the short-term acute effects of cannabis and withdrawal effects. A subsample of 1418 medical cannabis users further indicated the medical conditions for which they use cannabis and its perceived efficacy. Results: The results indicated that men reported using cannabis more frequently and in higher quantities than did women. Men were more likely to report using joints/blunts, vaporizers, and concentrates, while women were more likely to report using pipes and oral administration. Men were more likely than women to report increased appetite, improved memory, enthusiasm, altered time perception, and increased musicality when high, while women were more likely than men to report loss of appetite and desire to clean when high. Men were more likely than women to report insomnia and vivid dreams during periods of withdrawal, while women were more likely than men to report nausea and anxiety as withdrawal symptoms. Sex differences in the conditions for which medical cannabis is used, and its efficacy, were trivial. Conclusions: These results may be used to focus research on biological and psychosocial mechanisms underlying cannabis-related sex differences, to inform clinicians treating individuals with cannabis use disorders, and to inform cannabis consumers, clinicians, and policymakers about the risks and benefits of cannabis for both sexes.
Gilman, Jodi M
Although peer influence is an important factor in the initiation and maintenance of cannabis use, few studies have investigated the neural correlates of peer influence among cannabis users. The current review summarizes research on the neuroscience of social influence in cannabis users, with the goal of highlighting gaps in the literature and the need for future research. Brain regions underlying peer influence may function differently in cannabis users. Compared to non-using controls, regions of the brain underlying reward, such as the striatum, show greater connectivity with frontal regions, and also show hyperactivity when participants are presented with peer information. Other subcortical regions, such as the insula, show hypoactivation during social exclusion in cannabis users, indicating that neural responses to peer interactions may be altered in cannabis users. Although neuroscience is increasingly being used to study social behavior, few studies have specifically focused on cannabis use, and therefore it is difficult to draw conclusions about social mechanisms that may differentiate cannabis users and controls. This area of research may be a promising avenue in which to explore a critical factor underlying cannabis use and addiction.
Samantha J. Broyd
Full Text Available Prolonged heavy exposure to cannabis is associated with impaired cognition and brain functional and structural alterations. We recently reported attenuated mismatch negativity (MMN and altered P50 sensory gating in chronic cannabis users. This study investigated the extent of brain functional recovery (indexed by MMN and P50 in chronic users after cessation of use. Eighteen ex-users (median 13.5 years prior regular use; median 3.5 years abstinence and 18 nonusers completed (1 a multifeature oddball task with duration, frequency, and intensity deviants and (2 a P50 paired-click paradigm. Trend level smaller duration MMN amplitude and larger P50 ratios (indicative of poorer sensory gating were observed in ex-users compared to controls. Poorer P50 gating correlated with prior duration of cannabis use. Duration of abstinence was positively correlated with duration MMN amplitude, even after controlling for age and duration of cannabis use. Impaired sensory gating and attenuated MMN amplitude tended to persist in ex-users after prolonged cessation of use, suggesting a lack of full recovery. An association with prolonged duration of prior cannabis use may indicate persistent cannabis-related alterations to P50 sensory gating. Greater reductions in MMN amplitude with increasing abstinence (positive correlation may be related to either self-medication or an accelerated aging process.
Malouff, John M; Johnson, Caitlin E; Rooke, Sally E
Introduction: Although cannabis use creates health risks, governments have recently been legalizing either medical use or leisure use. These governments can mandate health warnings on cannabis packages. Prior research examined recommended warnings of cannabis experts. The aim of this study was to obtain suggested cannabis health and safety warnings from cannabis users. Methods: We used a media release, Facebook postings, and announcements in university classes to seek individuals who had used cannabis at least once according to their own report. Using online data collection software that keeps participants anonymous, we asked the individuals to suggest a warning that governments could mandate on cannabis packages. Results: In total, 288 users suggested warnings. Categorizing the warnings into content categories led to six warning topics: (1) risk of harm to mental health and psychological functioning; (2) risk of operating machinery while under the influence; (3) short-term physical side effects; (4) responsible use; (5) long-term negative physical effects; and (6) dependence, addiction, or abuse. The user-suggested warnings overlapped with six expert-recommended warnings identified in prior survey research and included two content areas that did not feature in expert-recommended warnings: short-term physical side effects and the importance of responsible use. Conclusions: The results are consistent with prior findings that some youths perceive cannabis use as potentially harmful. The current findings provide possible new content for warnings on cannabis packages.
Stitzer, Maxine L.; Vandrey, Ryan
Rationale Little is known about the smoking topography characteristics of heavy cannabis users. Such measures may be able to predict cannabis use-related outcomes and could be used to validate self-reported measures of cannabis use. Objectives The current study was conducted to measure cannabis smoking topography characteristics during periods of ad libitum use and to correlate topography assessments with measures of self-reported cannabis use, withdrawal and craving during abstinence, and cognitive task performance. Methods Participants (N=20) completed an inpatient study in which they alternated between periods of ad libitum cannabis use and abstinence. Measures of self-reported cannabis use, smoking topography, craving, withdrawal, and sleep measures were collected. Results Participants smoked with greater intensity (e.g., greater volume, longer duration) on initial cigarette puffs with a steady decline on subsequent puffs. Smoking characteristics were significantly correlated with severity of withdrawal, notably sleep quality and architecture, and craving during abstinence, suggesting dose-related effects of cannabis use on these outcomes. Smoking characteristics generally were not significantly associated with cognitive performance. Smoking topography measures were significantly correlated with self-reported measures of cannabis use, indicating validity of these assessments, but topography measures were more sensitive than self-report in predicting cannabis-related outcomes. Conclusions A dose–effect relationship between cannabis consumption and outcomes believed to be clinically important was observed. With additional research, smoking topography assessments may become a useful clinical tool. PMID:21922170
Pearce, Daniel D; Mitsouras, Katherine; Irizarry, Kristopher J
To evaluate the opinions of medical cannabis (MC) users on the effects of Cannabis indica vs. those of Cannabis sativa on conditions and symptoms through an online survey. Survey of 95 non-randomly assigned MC users. A two-sided chi-square test followed by Bonferroni post hoc multiple comparison and Fisher exact test were used to determine correlations. The Cronbach α was used to determine internal consistency. Announcements on 13 MC websites with links to SurveyMonkey.com. Self-identified MC users. Web survey. Species effects were compared regarding health symptoms, conditions, purpose, route, and trust in product label. Trust in the purity, the route of administration, or the purpose (recreational vs. medicinal) did not differ between the two species. A preference for C. indica was statistically significant for pain management (p=0.001), helping with sedation (p=0.015), and sleep (p<0.001). C. sativa was preferred for euphoria (p<0.001) and enhancing energy (p=0.022). The conditions reaching statistical significance for C. indica preference were: nonmigraine headaches (p=0.042), glaucoma (p=0.036), neuropathy (p=0.024), spasticity (p=0.048), seizures (p=0.031), insomnia (p<0.001), and joint pain (p=0.048). For C. sativa, no conditions reached significance. The MC websites' descriptions of effects that agreed with the survey results are listed. Some conditions had very few respondents. The internal consistency/reliability (Cronbach α) was adequate for the condition scale but not for the symptom survey. In this anonymous Web survey, which had limitations, the two species had different effect associations on symptoms and conditions, possibly because of ingredient differences. Future surveys and subsequent prospective definitive trials are needed to confirm the findings.
Flavel, Stanley C; White, Jason M; Todd, Gabrielle
To investigate movement speed and rhythmicity in abstinent cannabis users, we hypothesized that abstinent cannabis users exhibit decreased maximal finger tapping frequency and increased variability of tapping compared with non-drug users. The study involved 10 healthy adult cannabis users and 10 age-matched and gender-matched controls with no history of illicit drug use. Subjects underwent a series of screening tests prior to participation. Subjects were then asked to tap a strain gauge as fast as possible with the index finger of their dominant hand (duration 5 s). The average intertap interval did not significantly differ between groups, but the coefficient of variation of the intertap interval was significantly greater in the cannabis group than in controls (p=0.011). The cannabis group also exhibited a slow tapping frequency at the beginning of the task. Rhythmicity of finger tapping is abnormal in individuals with a history of cannabis use. The abnormality appears to be long lasting and adds to the list of functional changes present in abstinent cannabis users. Copyright © 2013 John Wiley & Sons, Ltd.
Lewis, John; Molnar, Anna; Allsop, David; Copeland, Jan; Fu, Shanlin
Urinary 11-nor-Δ(9)-tetrahydrocannabinol-9-carboxylic acid (Carboxy-THC) concentrations, normalised to creatinine output, have been demonstrated to be a useful tool in the interpretation of the results of a series of urine tests for cannabis. These tests, often termed historical data, can be used to identify potential chronic cannabis users who may present occupational health and safety risks within the workplace. Conversely, the data can also be used to support employee claims of previous regular, rather than recent, cannabis use. This study aimed at examining the mean elimination of Carboxy-THC in 37 chronic users undergoing voluntary abstinence over a 2-week period. Urine specimens were collected prior to the study and after 1 and 2 weeks of abstinence. Carboxy-THC levels in urine were measured by gas chromatography-mass spectrometry (GC-MS) following alkaline hydrolysis, organic solvent extraction and derivatisation to form its pentafluoropropionic derivative. The creatinine-normalised Carboxy-THC concentrations declined rapidly over the 2 weeks of abstinence period and the majority of chronic cannabis users (73%) reduced their urinary Carboxy-THC levels to below the 15-μg/L confirmatory cutoff within that time. The study further highlights the value of historical urinary Carboxy-THC data as a means of identifying potential occupational health and safety risks among chronic cannabis users.
van der Pol, P.; Liebregts, N.; de Graaf, R.; Korf, D.J.; van den Brink, W.; van Laar, M.
The Severity of Dependence Scale (SDS) measures with five items the degree of psychological dependence on several illicit drugs, including cannabis. Its psychometric properties have not yet been examined in young adult frequent cannabis users, an eminently high-risk group for cannabis dependence.
Full Text Available A potentially powerful predictor for the course of drug (abuse is the approach-bias, that is, the pre-reflective tendency to approach rather than avoid drug-related stimuli. Here we investigated the neural underpinnings of cannabis approach and avoidance tendencies. By elucidating the predictive power of neural approach-bias activations for future cannabis use and problem severity, we aimed at identifying new intervention targets. Using functional Magnetic Resonance Imaging (fMRI, neural approach-bias activations were measured with a Stimulus Response Compatibility task (SRC and compared between 33 heavy cannabis users and 36 matched controls. In addition, associations were examined between approach-bias activations and cannabis use and problem severity at baseline and at six-month follow-up. Approach-bias activations did not differ between heavy cannabis users and controls. However, within the group of heavy cannabis users, a positive relation was observed between total lifetime cannabis use and approach-bias activations in various fronto-limbic areas. Moreover, approach-bias activations in the dorsolateral prefrontal cortex (DLPFC and anterior cingulate cortex (ACC independently predicted cannabis problem severity after six months over and beyond session-induced subjective measures of craving. Higher DLPFC/ACC activity during cannabis approach trials, but lower activity during cannabis avoidance trials were associated with decreases in cannabis problem severity. These findings suggest that cannabis users with deficient control over cannabis action tendencies are more likely to develop cannabis related problems. Moreover, the balance between cannabis approach and avoidance responses in the DLPFC and ACC may help identify individuals at-risk for cannabis use disorders and may be new targets for prevention and treatment.
Cousijn, Janna; Goudriaan, Anna E; Ridderinkhof, K Richard; van den Brink, Wim; Veltman, Dick J; Wiers, Reinout W
A potentially powerful predictor for the course of drug (ab)use is the approach-bias, that is, the pre-reflective tendency to approach rather than avoid drug-related stimuli. Here we investigated the neural underpinnings of cannabis approach and avoidance tendencies. By elucidating the predictive power of neural approach-bias activations for future cannabis use and problem severity, we aimed at identifying new intervention targets. Using functional Magnetic Resonance Imaging (fMRI), neural approach-bias activations were measured with a Stimulus Response Compatibility task (SRC) and compared between 33 heavy cannabis users and 36 matched controls. In addition, associations were examined between approach-bias activations and cannabis use and problem severity at baseline and at six-month follow-up. Approach-bias activations did not differ between heavy cannabis users and controls. However, within the group of heavy cannabis users, a positive relation was observed between total lifetime cannabis use and approach-bias activations in various fronto-limbic areas. Moreover, approach-bias activations in the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC) independently predicted cannabis problem severity after six months over and beyond session-induced subjective measures of craving. Higher DLPFC/ACC activity during cannabis approach trials, but lower activity during cannabis avoidance trials were associated with decreases in cannabis problem severity. These findings suggest that cannabis users with deficient control over cannabis action tendencies are more likely to develop cannabis related problems. Moreover, the balance between cannabis approach and avoidance responses in the DLPFC and ACC may help identify individuals at-risk for cannabis use disorders and may be new targets for prevention and treatment.
Silins, Edmund; Swift, Wendy; Slade, Tim; Toson, Barbara; Rodgers, Bryan; Hutchinson, Delyse M
The extent to which young adult former cannabis users fare better than infrequent users is unclear. We investigated the association between cannabis use status at age 23 and substance use and mental health outcomes at age 27. Data were from the 20+ year cohort of the PATH Through Life Study. Lifetime cannabis users (n = 1410) at age 23 were classified as former/occasional/regular users. Multivariable logistic regression was used to estimate the association between cannabis use status at age 23 and six outcomes assessed at age 27. Compared with occasional cannabis users: (i) former users had odds of subsequent tobacco use [odds ratio (OR) = 0.67, 95% confidence interval (CI) 0.52-0.85], illicit drug use (cannabis, OR = 0.22, 95% CI 0.17-0.28; other illicit drugs, OR = 0.29, 95% CI 0.22-0.39) and mental health impairment (OR = 0.71, 95% CI 0.55-0.92) that were 29-78% lower; and (ii) regular users had odds of subsequent frequent alcohol use (OR = 2.34, 95% CI 0.67-1.34), tobacco use (OR = 3.67, 95% CI 2.54-5.30), cannabis use (OR = 11.73, 95% CI 6.81-20.21) and dependence symptoms (OR = 12.60, 95% CI 8.38-18.94), and other illicit drug use (OR = 2.95, 95% CI 2.07-4.21) that were 2-13 times greater. Associations attenuated after covariate adjustment, and most remained significant. Clear associations exist between cannabis use status in young adulthood and subsequent mental health and substance use. While early intervention remains important to prevent regular cannabis use and the associated harms, experimentation with cannabis use in the years leading into young adulthood may not necessarily determine an immutable pathway to mental health problems and illicit substance use. [Silins E, Swift W, Slade T, Toson B, Rodgers B, Hutchinson DM. A prospective study of the substance use and mental health outcomes of young adult former and current cannabis users. Drug Alcohol Rev 2017;00:000-000]. © 2017 Australasian Professional Society on Alcohol and other
Weinstein, Aviv; Livny, Abigail; Weizman, Abraham
Cannabis is the most widely used illicit drug worldwide. Regular cannabis use has been associated with a range of acute and chronic mental health problems, such as anxiety, depression, psychotic symptoms and neurocognitive impairments and their neural mechanisms need to be examined. This review summarizes and critically evaluates brain-imaging studies of cannabis in recreational and regular cannabis users between January 2000 and January 2016. The search has yielded eligible 103 structural and functional studies. Regular use of cannabis results in volumetric, gray matter and white matter structural changes in the brain, in particular in the hippocampus and the amygdala. Regular use of cannabis affects cognitive processes such as attention, memory, inhibitory control, decision-making, emotional processing, social cognition and their associated brain areas. There is evidence that regular cannabis use leads to altered neural function during attention and working memory and that recruitment of activity in additional brain regions can compensate for it. Similar to other drugs of abuse, cannabis cues activated areas in the reward pathway. Pharmacological studies showed a modest increase in human striatal dopamine transmission after administration of THC in healthy volunteers. Regular cannabis use resulted in reduced dopamine transporter occupancy and reduced dopamine synthesis but not in reduced striatal D2/D3 receptor occupancy compared with healthy control participants. Studies also showed different effects of Δ-9 tetrahydrocannabinol (THC) and cannabidiol (CBD) on emotion, cognition and associated brain regions in healthy volunteers, whereby CBD protects against the psychoactive effects of THC. Brain imaging studies using selective high-affinity radioligands for the imaging of cannabinoid CB1 receptor availability in Positron Emission Tomography (PET) showed downregulation of CB1 in regular users of cannabis. In conclusion, regular use of the cannabinoids exerts
This article presents the results of a study of two SMS services aimed at providing young people with information on cannabis and helping them to reduce their consumption of the drug. The attitude of the 12 participants in the study towards the SMS services is generally positive, but they prefer...... factual information to advice and counselling. The messages prompt reflection and awareness among the recipients, and their repetitive, serial nature plays a significant part in the process of change. This is especially true of the young people whose use of cannabis is recreational. For them, the SMS...
Beraha, E.M.; Cousijn, J.; Hermanides, E.; Goudriaan, A.E.; Wiers, R.W.
Cognitive biases, including implicit memory associations are thought to play an important role in the development of addictive behaviors. The aim of the present study was to investigate implicit affective memory associations in heavy cannabis users. Implicit positive-arousal, sedation, and negative
Buckner, Julia D; Zvolensky, Michael J; Crosby, Ross D; Wonderlich, Stephen A; Ecker, Anthony H; Richter, Ashley
Cannabis remains the most commonly used illicit substance and use rates are rising. Notably, the prevalence of cannabis use disorders (CUD) nearly equals that of other illicit substance use disorders combined. Thus, the present study aimed to identify cognitive, affective, and situational predictors and consequences of ad-lib cannabis use in a racially diverse sample. The sample consisted of 93 current cannabis users (34.4% female; 57.1% non-Hispanic Caucasian), 87.1% of whom evinced a current CUD. Ecological Momentary Assessment was used to collect frequent ratings of cannabis withdrawal, craving, affect, cannabis use motives, and peer cannabis use over two weeks. Mixed effects linear models examined within- and between-day correlates and consequences of cannabis use. Withdrawal and craving were higher on cannabis use days than non-use days. Withdrawal, craving, and positive and negative affect were higher immediately prior to cannabis use compared to non-use episodes. Withdrawal and craving were higher among those who subsequently used cannabis than those who did not. Cannabis use resulted in less subsequent withdrawal, craving, and negative affect. Enhancement and coping motives were the most common reasons cited for use. Withdrawal and negative affect were related to using cannabis for coping motives and social motives. Participants were most likely to use cannabis if others were using, and withdrawal and craving were greater in social situations when others were using. Data support the contention that cannabis withdrawal and craving and affect and peer use play important roles in the maintenance of cannabis use. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Korf, Dirk J; Benschop, Annemieke; Wouters, Marije
To determine whether a classification of cannabis users into different types can help to clarify the relationship between cannabis potency and consumption behaviour, harmful physical effects and psychological dependency. A field sample of 388 respondents was recruited who had smoked cannabis at least once in the past month. They were contacted and interviewed in 28 cannabis coffee shops located in five Dutch cities. Data were collected with an assisted self-completion questionnaire. Cluster analysis was performed using the k-means method. Various ways were observed in which cannabis users in natural settings adjusted their intake to the potency of the drug. Cluster analysis identified three broad types of cannabis users. The strongest high type was the youngest, consumed the highest monthly dose, inhaled higher-potency cannabis more deeply, and scored highest on psychological cannabis dependency. The consistent high type preferred milder cannabis, consumed the lowest monthly dose, and compensated for stronger cannabis by inhaling less deeply and smoking less. The steady quantity type was the oldest, usually smoked alone, consumed an intermediate monthly dose, and did not tend to adjust the depth of inhalation to the potency of the cannabis. The results suggest that this typology might also reflect three successive stages in the careers of continuing cannabis users. Laboratory studies to assess the effects of higher THC concentrations on external and internal exposure to cannabis should allow for the possibility that the types of users studied can affect the results.
Lucy J. Troup
Full Text Available As part of an ongoing research program into the relationship between cannabis use and emotion processing, participants were assessed on their level of cannabis exposure using the Recreational Cannabis Use Examination, a measure developed specifically to assess cannabis use in Colorado post state legalization. Three groups were created based on self-reported use: a control group who have never used, a casual user group and a chronic user group. Each participant also completed two measures of mood assessment, the Center for Epidemiologic Studies Depression Scale and the State-Trait Anxiety Inventory. Relationships between cannabis use groups and scores on these measures were then analyzed using both correlations and multivariate analysis of variance. Results indicate a relationship between casual cannabis use and scoring highly for depressive symptomatology on the Center for Epidemiologic Studies Depression Scale. There were no significant relationships between cannabis use and scores on the State-Trait Anxiety Inventory.
Zimmermann, Kaeli; Walz, Christina; Derckx, Raissa T; Kendrick, Keith M; Weber, Bernd; Dore, Bruce; Ochsner, Kevin N; Hurlemann, René; Becker, Benjamin
Effective regulation of negative affective states has been associated with mental health. Impaired regulation of negative affect represents a risk factor for dysfunctional coping mechanisms such as drug use and thus could contribute to the initiation and development of problematic substance use. This study investigated behavioral and neural indices of emotion regulation in regular marijuana users (n = 23) and demographically matched nonusing controls (n = 20) by means of an fMRI cognitive emotion regulation (reappraisal) paradigm. Relative to nonusing controls, marijuana users demonstrated increased neural activity in a bilateral frontal network comprising precentral, middle cingulate, and supplementary motor regions during reappraisal of negative affect (P marijuana users relative to controls. Together, the present findings could reflect an unsuccessful attempt of compensatory recruitment of additional neural resources in the context of disrupted amygdala-prefrontal interaction during volitional emotion regulation in marijuana users. As such, impaired volitional regulation of negative affect might represent a consequence of, or risk factor for, regular marijuana use. Hum Brain Mapp 38:4270-4279, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Battisti, Robert A; Roodenrys, Steven; Johnstone, Stuart J; Pesa, Nicole; Hermens, Daniel F; Solowij, Nadia
Chronic cannabis use has been related to deficits in cognition (particularly memory) and the normal functioning of brain structures sensitive to cannabinoids. There is increasing evidence that conflict monitoring and resolution processes (i.e. the ability to detect and respond to change) may be affected. This study examined the ability to inhibit an automatic reading response in order to activate a more difficult naming response (i.e. conflict resolution) in a variant of the discrete trial Stroop colour-naming task. Event-related brain potentials to neutral, congruent and incongruent trials were compared between 21 cannabis users (mean 16.4 years of near daily use) in the unintoxicated state and 19 non-using controls. Cannabis users showed increased errors on colour-incongruent trials (e.g. "RED" printed in blue ink) but no performance differences from controls on colour congruent (e.g. "RED" printed in red ink) or neutral trials (e.g. "*****" printed in green ink). Poorer incongruent trial performance was predicted by an earlier age of onset of regular cannabis use. Users showed altered expression of a late sustained potential related to conflict resolution, evident by opposite patterns of activity between trial types at midline and central sites, and altered relationships between neurophysiological and behavioural outcome measures not evident in the control group. These findings indicate that chronic use of cannabis may impair the brain's ability to respond optimally in the presence of events that require conflict resolution and hold implications for the ability to refrain from substance misuse and/or maintain substance abstention behaviours.
Rosen, Alexis S; Sodos, Louise M; Hirst, Rayna B; Vaughn, Dylan; Lorkiewicz, Sara A
Experts have recommended criteria (Gonzalez et al., 2002) for recruiting pure chronic cannabis users (i.e., those without polysubstance use or psychiatric illness) when evaluating cannabis' non-acute effects on cognition. We sought to demonstrate the implications of using such criteria by examining characteristics of respondents who completed an eligibility screening for a parent study evaluating the cognitive effects of chronic cannabis use. Over a 3-year, 8-month period, 612 respondents from the community completed an eligibility screening based on recommendations in the cannabis literature. Using independent samples t-tests and chi-square tests, we examined whether qualified/eligible respondents (n = 219) differed from non-qualified/ineligible respondents (n = 393). Compared to ineligible cannabis users, eligible cannabis-using respondents were significantly younger, used cannabis more frequently, used alcohol less frequently, and were less likely to have a history of other drug use, a psychiatric diagnosis, or to have used psychiatric medication. Conclusions/Importance: Our findings indicate that eligible/pure cannabis users are not representative of typical cannabis users in the general community (i.e., ineligible users with polysubstance use and/or psychiatric diagnoses) who ultimately comprised the majority of our cannabis-using sample (65.2%). Thus, typical cannabis users may be more accurately characterized as polysubstance users, posing a number of challenges related to the generalizability of findings from studies utilizing pure samples of cannabis users. Recruiting samples of typical cannabis users will improve external validity in research. Furthermore, reporting comprehensive characteristics of such samples will enable consumers to gauge the applicability of study findings to populations of interest.
LaFrance, Emily M; Cuttler, Carrie
Previous research suggests cannabis may enhance some aspects of creativity, although the results remain somewhat equivocal. Moreover, it is unclear whether differences in cannabis users' personalities may account for any potentially beneficial effects of cannabis on creativity. This study was designed to examine whether sober cannabis users demonstrate superior self-reported and objective creativity test performance relative to non-users, and to determine whether any of the Big 5 personality domains underlie these effects. A sample of sober cannabis users (n=412) and non-users (n=309) completed measures of cannabis consumption, personality, self-reported and objective creativity. Relative to non-users, sober cannabis users self-reported higher creativity, and performed significantly better on a measure of convergent thinking. Controlling for cannabis users' higher levels of openness to experience abolished these effects. Therefore, while cannabis users appear to demonstrate enhanced creativity, these effects are an artifact of their heightened levels of openness to experience. Copyright © 2017 Elsevier Inc. All rights reserved.
Lisdahl, Krista M; Tamm, Leanne; Epstein, Jeffery N; Jernigan, Terry; Molina, Brooke S G; Hinshaw, Stephen P; Swanson, James M; Newman, Erik; Kelly, Clare; Bjork, James M
Both Attention Deficit Hyperactivity Disorder (ADHD) and chronic cannabis (CAN) use have been associated with brain structural abnormalities, although little is known about the effects of both in young adults. Participants included: those with a childhood diagnosis of ADHD who were CAN users (ADHD_CAN; n=37) and non-users (NU) (ADHD_NU; n=44) and a local normative comparison group (LNCG) who did (LNCG_CAN; n=18) and did not (LNCG_NU; n=21) use CAN regularly. Multiple regressions and MANCOVAs were used to examine the independent and interactive effects of a childhood ADHD diagnosis and CAN group status and age of onset (CUO) on subcortical volumes and cortical thickness. After controlling for age, gender, total brain volume, nicotine use, and past-year binge drinking, childhood ADHD diagnosis did not predict brain structure; however, persistence of ADHD was associated with smaller left precentral/postcentral cortical thickness. Compared to all non-users, CAN users had decreased cortical thickness in right hemisphere superior frontal sulcus, anterior cingulate, and isthmus of cingulate gyrus regions and left hemisphere superior frontal sulcus and precentral gyrus regions. Early cannabis use age of onset (CUO) in those with ADHD predicted greater right hemisphere superior frontal and postcentral cortical thickness. Young adults with persistent ADHD demonstrated brain structure abnormalities in regions underlying motor control, working memory and inhibitory control. Further, CAN use was linked with abnormal brain structure in regions with high concentrations of cannabinoid receptors. Additional large-scale longitudinal studies are needed to clarify how substance use impacts neurodevelopment in youth with and without ADHD. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.
The Motivational Enhancement Therapy and Cognitive Behavioral Therapy Supplement: 7 Sessions of Cognitive Behavioral Therapy for Adolescent Cannabis Users, Cannabis Youth Treatment (CYT) Series, Volume 2.
Webb, Charles; Scudder, Meleney; Kaminer, Yifrah; Kaden, Ron
This manual, a supplement to "Motivational Enhancement Therapy and Cognitive Behavioral Therapy for Adolescent Cannabis Users: 5 Sessions, Cannabis Youth Treatment (CYT) Series, Volume 1", presents a seven-session cognitive behavioral treatment (CBT7) approach designed especially for adolescent cannabis users. It addresses the implementation and…
Di Forti, Marta; Sallis, Hannah; Allegri, Fabio; Trotta, Antonella; Ferraro, Laura; Stilo, Simona A.; Marconi, Arianna; La Cascia, Caterina; Reis Marques, Tiago; Pariante, Carmine; Dazzan, Paola; Mondelli, Valeria; Paparelli, Alessandra; Kolliakou, Anna; Prata, Diana; Gaughran, Fiona; David, Anthony S.; Morgan, Craig; Stahl, Daniel; Khondoker, Mizanur; MacCabe, James H.; Murray, Robin M.
Cannabis use is associated with an earlier age of onset of psychosis (AOP). However, the reasons for this remain debated. Methods: We applied a Cox proportional hazards model to 410 first-episode psychosis patients to investigate the association between gender, patterns of cannabis use, and AOP. Results: Patients with a history of cannabis use presented with their first episode of psychosis at a younger age (mean years = 28.2, SD = 8.0; median years = 27.1) than those who never used cannabis (mean years = 31.4, SD = 9.9; median years = 30.0; hazard ratio [HR] = 1.42; 95% CI: 1.16–1.74; P cannabis at age 15 or younger had an earlier onset of psychosis (mean years = 27.0, SD = 6.2; median years = 26.9) than those who had started after 15 years (mean years = 29.1, SD = 8.5; median years = 27.8; HR = 1.40; 95% CI: 1.06–1.84; P = .050). Importantly, subjects who had been using high-potency cannabis (skunk-type) every day had the earliest onset (mean years = 25.2, SD = 6.3; median years = 24.6) compared to never users among all the groups tested (HR = 1.99; 95% CI: 1.50- 2.65; P cannabis had an onset an average of 6 years earlier than that of non-cannabis users. Conclusions: Daily use, especially of high-potency cannabis, drives the earlier onset of psychosis in cannabis users. PMID:24345517
Looby, Alison; Earleywine, Mitch
Research reveals mixed results for the effects of cannabis on cognitive functioning. These divergent results might stem from stereotype threat (ST), which occurs when individuals believe that a group to which they belong is inferior, resulting in poor test performance. Widespread media coverage of purported cannabis-related deficits in cognitive functioning may elicit ST among cannabis users, particularly among men, who may be more likely than women to identify with the cannabis-user stereotype. To investigate this hypothesis, cannabis users (30 male, 27 female) read a summary of research indicating either that cannabis produced deficits (ST condition), or that cannabis actually created no changes in cognitive functions. Participants then completed cognitive tests. Examination of the gender x condition interaction revealed significant results on 4 tests: the California Verbal Learning Test-II immediate recall task, the Controlled Oral Word Association Test for number of words generated and number of switches between clusters, and the Digit Symbol Substitution Task. Males exposed to ST performed worse on all tests compared to men not exposed to ST, while women exposed to ST performed better than women not exposed. These results suggest that cognitive deficits observed in male cannabis users may be attributed to ST rather than decreased functioning. Surprisingly, women in the ST condition scored higher than controls. Perhaps female users do not identify with the typical cannabis stereotype. This study highlights the importance of disconfirming relevant stereotypes prior to examination of the cognitive abilities of cannabis users. Copyright 2010 Elsevier Ltd. All rights reserved.
Full Text Available There is a growing need to provide treatment for cannabis users, yet engaging and maintaining this population in treatment is particularly difficult. Although past research has focused on the importance of therapeutic alliance on drug treatment outcomes, this is the first study to examine the dimensions of therapeutic alliance for cannabis users compared with users of alcohol or other drugs in a naturalistic setting. The acceptability of Internet-delivered interventions for drug and alcohol treatments is also investigated. Participants (N = 77 included clients who were receiving outpatient drug and alcohol treatment at a publicly-funded health service, including a Specialist Cannabis Clinic. The results indicated that one particular domain of alliance, Bond, was consistently lower, from both client and clinician perspectives, for current cannabis users relative to those not currently using cannabis. Client perceptions of Bond decreased as the severity of cannabis use increased (r =-0.373, p=0.02. Cannabis Clinic clients did not report a significantly lower Bond with their clinicians, suggesting that specialised cannabis services may be better placed to provide appropriate treatment for this population than embedding cannabis treatment within traditional drug and alcohol treatment teams. In addition, Internet/computer based treatments may be one potential way to engage, transition or retain cannabis users in treatment.Trial Registration: Australian Clinical Trial Registration Number: ACTRN12611000382976
Gunderson, Erik W; Haughey, Heather M; Ait-Daoud, Nassima; Joshi, Amruta S; Hart, Carl L
Despite growing concern about the increased rates of synthetic cannabinoid (SC) use and their effects, only limited data are available that addresses these issues. This study assessed the extent of SC product use and reported effects among a cohort of adult marijuana and tobacco users. A brief telephone interview was conducted with individuals who had given permission to be contacted for future research while screening for a cannabis/nicotine dependence medication development study (NCT01204723). Respondents (N = 42; 88% participation rate) were primarily young adults, male, racially diverse, and high school graduates. Nearly all currently smoked tobacco and cannabis, with 86% smoking cannabis on 5 or more days per week. Nearly all (91%) were familiar with SC products, half (50%) reported smoking SC products previously, and a substantial minority (24%) reported current use (i.e., past month). Despite a federal ban on 5 common SCs, which went into effect on March 1, 2011, a number of respondents reported continued SC product use. Common reasons reported for use included, but were not limited to, seeking a new "high" similar to that produced by marijuana and avoiding drug use detection via a positive urine screen. The primary side effects were trouble thinking clearly, headache, dry mouth, and anxiety. No significant differences were found between synthetic cannabinoid product users (ever or current) and nonusers by demographics or other characteristics. Among current marijuana and tobacco users, SC product consumption was common and persisted despite a federal ban. The primary reasons for the use of SC-containing products seem to be to evade drug detection and to experience a marijuana-like high.
Benschop, Annemieke; Liebregts, Nienke; van der Pol, Peggy; Schaap, Rick; Buisman, Renate; van Laar, Margriet; van den Brink, Wim; de Graaf, Ron; Korf, Dirk J
The Marijuana Motives Measure (MMM) has so far been examined mainly in student populations, often with relatively limited involvement in cannabis use. This study evaluated the factor structure of the MMM in a demographically mixed sample of 600 young adult (18-30 years) frequent (≥ 3 days per week) cannabis users in the Netherlands. Analysis confirmed a five-factor solution, denoting coping, enhancement, social, conformity and expansion motives. Additionally, the original MMM was extended with two items (boredom and habit), which formed a distinct, internally consistent sixth factor labelled routine motives. In a multivariable logistic regression analysis, coping and routine motives showed significant associations with 12-month DSM-IV cannabis dependence. The results suggest general reliability and validity of the MMM in a heterogeneous population of experienced cannabis users. Copyright © 2014 Elsevier Ltd. All rights reserved.
Full Text Available Life course theory considers events in study and work as potential turning points in deviance, including illicit drug use. This qualitative study explores the role of occupational life in cannabis use and dependence in young adults. Two and three years after the initial structured interview, 47 at baseline frequent cannabis users were interviewed in-depth about the dynamics underlying changes in their cannabis use and dependence. Overall, cannabis use and dependence declined, including interviewees who quit using cannabis completely, in particular with students, both during their study and after they got employed. Life course theory appeared to be a useful framework to explore how and why occupational life is related to cannabis use and dependence over time. Our study showed that life events in this realm are rather common in young adults and can have a strong impact on cannabis use. While sometimes changes in use are temporary, turning points can evolve from changes in educational and employment situations; an effect that seems to be related to the consequences of these changes in terms of amount of leisure time and agency (i.e. feelings of being in control.
Joye, A. M.
This thesis assesses psychotic-like symptomatology and reward responsivity in chronic users of two illicit drugs, cannabis and ketamine. As use of these drugs is steadily increasing, with cannabis being the most widely used drug worldwide (following alcohol, caffeine and tobacco) and the recent proliferation of ketamine misuse in parts of Asia, Europe and the United States, it is important to examine the effects of their habitual use. While research has linked cannabis use to sub-clinical psy...
Nusbaum, Amy T; Whitney, Paul; Cuttler, Carrie; Spradlin, Alexander; Hinson, John M; McLaughlin, Ryan J
Cannabis use has increased rapidly in recent decades. The increase in cannabis use makes it important to understand the potential influence of chronic use on attentional control and other executive functions (EFs). Because cannabis is often used to reduce stress, and because stress can constrain attentional control and EFs, the primary goal of this study was to determine the joint effect of acute stress and chronic cannabis use on specific EFs. Thirty-nine cannabis users and 40 non-users were assigned to either a stress or no stress version of the Maastricht Acute Stress Test. Participants then completed two cognitive tasks that involve EFs: (1) task switching, and (2) a novel Flexible Attentional Control Task. These two tasks provided assessments of vigilant attention, inhibitory control, top-down attentional control, and cognitive flexibility. Salivary cortisol was assessed throughout the study. Reaction time indices showed an interaction between stress and cannabis use on top-down attentional control (p=0.036, n p 2 =0.059). Follow-up tests showed that cannabis users relied less on top-down attentional control than did non-users in the no stress version. Despite not relying on top-down control, the cannabis users showed no overall performance deficits on the tasks. Chronic cannabis users performed cognitive tasks involving EFs as well as non-users while not employing cognitive control processes that are typical for such tasks. These results indicate alterations in cognitive processing in cannabis users, but such alterations do not necessarily lead to global performance deficits. Copyright © 2017 Elsevier B.V. All rights reserved.
Creemers, H.E.; Dijkstra, J.K.; Vollebergh, W.A.M.; Ormel, J.; Verhulst, F.C.; Huizink, A.C.
Aims The aim of the present study was to determine the mediating role of affiliation with cannabis-using peers in the pathways from various dimensions of temperament to life-time cannabis use, and to determine if these associations also contributed to the development of regular cannabis
Ross, J Megan; Graziano, Paulo; Pacheco-Colón, Ileana; Coxe, Stefany; Gonzalez, Raul
Results from research conducted on the association between cannabis use and body mass index (BMI) reveal mixed findings. It is possible that individual differences in decision-making (DM) abilities may influence these associations. This study analyzed how amount of cannabis use, DM performance, and the interaction of these variables influenced BMI and clinical classifications of weight among adolescents (ages 14 to 18 years; 56% male; 77% Hispanic). The sample consisted primarily of cannabis users (n=238) without a history of significant developmental disorders, birth complications, neurological conditions, or history of mood, thought, or attention deficit/hyperactivity disorder at screening. Furthermore, few participants engaged frequently in other drug use (except for alcohol and nicotine). Analyses revealed that more lifetime cannabis use was associated with a higher BMI and greater likelihood of being overweight/obese. Interactions between DM and cannabis use on BMI were not significant, and DM was not directly associated with BMI. Our findings suggest that among adolescents, cannabis use is associated with a greater BMI regardless of DM abilities and this association is not accounted for by other potential factors, including depression, alcohol use, nicotine use, race, ethnicity, or IQ. (JINS, 2016, 22, 944-949).
Sankar-Maharaj, Sasha; Chen, Deryk; Hariharan, Seetharaman
Postoperative shivering has been anecdotally observed to be frequent and severe in Cannabis smokers following general anesthesia in the Caribbean. The aim of this study was to compare the frequency and intensity of postoperative shivering in Cannabis users versus non-users. A prospective, cross-sectional, observational design was used. Demographic data were obtained. Patients were grouped into Cannabis users and non-users. All patients received standardized general anesthesia and were administered warmed fluids intraoperatively. Ambient room temperatures and clinical data were recorded. Patients' core body temperature was recorded at 10-minute intervals both in the operating room and the post-anesthesia care unit (PACU). Postoperatively an independent observer assessed the patients who had shivering using a scoring system ranging from 0 to 3. Treatment for shivering and post-treatment shivering scores were also recorded. Fifty-five patients were studied, of which 71% were male. There were 25 (45%) Cannabis users, of which 50% smoked 10 joints per week; 30 (55%) patients were non-users. The overall incidence of postoperative shivering was 36%; 16% had a shivering score of '3', 13% had '2' and 7% had a score of '1'. The incidence of postoperative shivering among Cannabis users was 40% while it was 33.3% in non-users. Also, 90% of Cannabis users had shivering scores of 2 and 3, compared to 70% of non-users. There was a higher incidence and intensity of shivering in Cannabis smokers, although the study could not establish a statistically significant difference in the frequency and severity of shivering between Cannabis users and non-users. Copyright © 2016 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.
Lovell, M E; Bruno, R; Johnston, J; Matthews, A; McGregor, I; Allsop, D J; Lintzeris, N
Cannabis intoxication adversely affects health, yet persistent effects following short-term abstinence in long-term cannabis users are unclear. This matched-subjects, cross-sectional study compared health outcomes of long-term cannabis and long-term tobacco-only users, relative to population norms. Nineteen long-term (mean 32.3years of use, mean age 55.7years), abstinent (mean 15h) cannabis users and 16 long-term tobacco users (mean 37.1years of use, mean age 52.9years), matched for age, educational attainment, and lifetime tobacco consumption, were compared on measures of learning and memory, response inhibition, information-processing, sustained attention, executive control, and mental and physical health. Cannabis users exhibited poorer overall learning and delayed recall and greater interference and forgetting than tobacco users, and exhibited poorer recall than norms. Inhibition and executive control were similar between groups, but cannabis users had slower reaction times during information processing and sustained attention tasks. Cannabis users had superior health satisfaction and psychological, somatic, and general health than tobacco users and had similar mental and physical health to norms whilst tobacco users had greater stress, role limitations from emotional problems, and poorer health satisfaction. Long-term cannabis users may exhibit deficits in some cognitive domains despite short-term abstinence and may therefore benefit from interventions to improve cognitive performance. Tobacco alone may contribute to adverse mental and physical health outcomes, which requires appropriate control in future studies. Copyright © 2017 Elsevier Ltd. All rights reserved.
Shere, Amar; Goyal, Hemant
Cannabis is one of the most commonly used illicit drugs in the United States and is considered to have several adverse health effects. There is evidence suggesting that its recreational use is associated with both increased cardio- and cerebrovascular events. Recently, multiple cases of ischemic and hemorrhagic strokes associated with cannabis use were reported in the literature (Goyal et al., 2017). It has been suggested that cannabis can affect cerebral auto-regulation and vascular tone leading to vasoconstriction and acute ischemic stroke. However, hemorrhagic strokes, which are often seen with sympathomimetic illicit drugs (e.g. cocaine and amphetamines), have rarely been reported due to cannabis. Many cellular mechanisms within non-ischemic tissue post stroke may be augmented by heavy cannabis use. Here, we describe a rapid development of hemorrhage following thrombolytic therapy in a patient with heavy cannabis use with an ischemic stroke. Copyright © 2017 Elsevier Inc. All rights reserved.
Enzi, Björn; Lissek, Silke; Edel, Marc-Andreas; Tegenthoff, Martin; Nicolas, Volkmar; Scherbaum, Norbert; Juckel, Georg; Roser, Patrik
Alterations in reward and punishment processing have been reported in adults suffering from long-term cannabis use. However, previous findings regarding the chronic effects of cannabis on reward and punishment processing have been inconsistent. In the present study, we used functional magnetic resonance imaging (fMRI) to reveal the neural correlates of reward and punishment processing in long-term cannabis users (n = 15) and in healthy control subjects (n = 15) with no history of drug abuse. For this purpose, we used the well-established Monetary Incentive Delay (MID) task, a reliable experimental paradigm that allows the differentiation between anticipatory and consummatory aspects of reward and punishment processing. Regarding the gain anticipation period, no significant group differences were observed. In the left caudate and the left inferior frontal gyrus, cannabis users were - in contrast to healthy controls - not able to differentiate between the conditions feedback of reward and control. In addition, cannabis users showed stronger activations in the left caudate and the bilateral inferior frontal gyrus following feedback of no punishment as compared to healthy controls. We interpreted these deficits in dorsal striatal functioning as altered stimulus-reward or action-contingent learning in cannabis users. In addition, the enhanced lateral prefrontal activation in cannabis users that is related to non-punishing feedback may reflect a deficit in emotion regulation or cognitive reappraisal in these subjects.
Full Text Available Alterations in reward and punishment processing have been reported in adults suffering from long-term cannabis use. However, previous findings regarding the chronic effects of cannabis on reward and punishment processing have been inconsistent. In the present study, we used functional magnetic resonance imaging (fMRI to reveal the neural correlates of reward and punishment processing in long-term cannabis users (n = 15 and in healthy control subjects (n = 15 with no history of drug abuse. For this purpose, we used the well-established Monetary Incentive Delay (MID task, a reliable experimental paradigm that allows the differentiation between anticipatory and consummatory aspects of reward and punishment processing. Regarding the gain anticipation period, no significant group differences were observed. In the left caudate and the left inferior frontal gyrus, cannabis users were - in contrast to healthy controls - not able to differentiate between the conditions feedback of reward and control. In addition, cannabis users showed stronger activations in the left caudate and the bilateral inferior frontal gyrus following feedback of no punishment as compared to healthy controls. We interpreted these deficits in dorsal striatal functioning as altered stimulus-reward or action-contingent learning in cannabis users. In addition, the enhanced lateral prefrontal activation in cannabis users that is related to non-punishing feedback may reflect a deficit in emotion regulation or cognitive reappraisal in these subjects.
Tânia Moraes Ramos Andrade
Full Text Available A depressão é um dos transtornos psiquiátricos mais comuns na adolescência. Os quadros depressivos costumam apresentar elevadas taxas de comorbidades psiquiátricas, sendo freqüente o abuso de substâncias psicoativas. O artigo investiga a associação dos sintomas depressivos e o uso da cannabis. MÉTODO: Revisão sistemática, análise dos artigos indexados no Medline, PsycInfo, ProQuest, Web of Science e Lilacs, entre 2000 e 2005, descritores: depressive symptoms, depressive, adolescence, teenager e cannabis. RESULTADOS: Revisados 36 artigos completos, resultando no estudo de 9 artigos, que tratam de sintomas depressivos ou depressão e o uso ou dependência de cannabis em adolescentes. Os estudos confirmam a associação entre sintomas depressivos e o uso de cannabis na adolescência, sendo esta associação mais freqüente no uso precoce e regular de cannabis. CONCLUSÃO: Os sintomas depressivos/depressão estão relacionados ao uso/abuso e dependência de cannabis na adolescência. A investigação clínica e os programas de prevenção devem abordar estes transtornos na adolescência.Este artículo busca investigar la asociación de los síntomas depresivos y el uso de cannabis en la adolescencia. MÉTODO: Ha sido realizado, a través de revisión sistemática, el análisis de los artículos indexados localizados en los sistemas Medline, PsycInfo, ProQuest, Web of Science y Lilacs, entre 2000 y 2005, utilizando los descriptores: depressive symptoms, depressive, adolescence, teenager y cannabis. RESULTADOS: La mayoría de los estudios confirma existir una asociación entre síntomas depresivos y el uso de cannabis en la adolescencia, cabe destacar que esta asociación es más frecuente en el uso precoz y regular de cañabais. CONCLUSIÓN: Los síntomas depresivos/Depresión están relacionados al uso/abuso y dependencia de cañabais en la adolescencia, siendo entonces importante que estas variables puedan ser investigadas en la pr
Rentzsch, Johannes; Stadtmann, Ada; Montag, Christiane; Kunte, Hagen; Plöckl, Doris; Hellweg, Rainer; Gallinat, Jürgen; Kronenberg, Golo; Jockers-Scherübl, Maria Christiane
Long-term cannabis use may confer cognitive deficits and increased risk of psychosis. However, the relationship between cannabis use and schizophrenia is complex. In particular, little is known about the effects of chronic cannabis use on the attention-related electric brain response in schizophrenia. We investigated auditory novelty and oddball P300 evoked potentials in a mixed sample of first-episode and chronic schizophrenic patients and healthy controls with (SZCA, n = 20; COCA, n = 20, abstinence ≥28 days) or without (SZ, n = 20; CO, n = 20) chronic cannabis use. Duration of regular cannabis use was 8.3 ± 5.6 (SZCA) and 9.1 ± 7.1 (COCA) years. In general, schizophrenic patients showed reduced P300 amplitudes. Cannabis use was associated with both a reduced early and late left-hemispheric novelty P300. There was a significant 'diagnosis × cannabis' interaction for the left-hemispheric late novelty P300 in that cannabis use was associated with a reduced amplitude in the otherwise healthy but not in the schizophrenic group compared with their relative control groups (corrected p 0.9, respectively). The left-hemispheric late novelty P300 in the otherwise healthy cannabis group correlated inversely with amount and duration of cannabis use (r = -0.50, p = 0.024; r = -0.57, p = 0.009, respectively). Our study confirms attentional deficits with chronic cannabis use. However, cannabis use may lead to different cognitive sequelae in patients with schizophrenia and in healthy controls, possibly reflecting preexisting alterations in the endocannabinoid system in schizophrenia.
Buckner, Julia D; Zvolensky, Michael J; Ecker, Anthony H; Jeffries, Emily R
Social anxiety disorder appears to be a risk factor for cannabis-related problems. Although it is presumed that increases in cannabis craving during elevated social anxiety reflect an intent to cope with greater negative affectivity, it is unclear whether increases in physiological arousal during social stress are related to cannabis craving, especially among those with social anxiety disorder. Similarly, no studies have assessed motivational reasons for cannabis use during elevated social stress. Thus, the current study tested whether increases in state social anxiety (measured subjectively and via physiological arousal) were related to greater cannabis craving among 126 current cannabis users (88.9% with cannabis use disorder, 31.7% with social anxiety disorder, 54.0% non-Hispanic Caucasian) randomly assigned to either a social interaction or reading task. As predicted, cannabis users in the social interaction condition reported greater cannabis craving than those in the reading condition. This effect was particularly evident among those with social anxiety disorder. Although physiological arousal did not moderate the relationship between condition and craving, coping motives were the most common reasons cited for wanting to use cannabis and were reported more among those in the social interaction task. These experimental results uniquely add to a growing literature suggesting the importance of elevated state social anxiety (especially among those with social anxiety disorder) in cannabis use vulnerability processes. PMID:26839322
Buckner, Julia D; Zvolensky, Michael J; Ecker, Anthony H; Jeffries, Emily R
Social anxiety disorder appears to be a risk factor for cannabis-related problems. Although it is presumed that increases in cannabis craving during elevated social anxiety reflect an intent to cope with greater negative affectivity, it is unclear whether increases in physiological arousal during social stress are related to cannabis craving, especially among those with social anxiety disorder. Similarly, no studies have assessed motivational reasons for cannabis use during elevated social stress. Thus, the current study tested whether increases in state social anxiety (measured subjectively and via physiological arousal) were related to greater cannabis craving among 126 current cannabis users (88.9% with cannabis use disorder, 31.7% with social anxiety disorder, 54.0% non-Hispanic Caucasian) randomly assigned to either a social interaction or reading task. As predicted, cannabis users in the social interaction condition reported greater cannabis craving than those in the reading condition. This effect was particularly evident among those with social anxiety disorder. Although physiological arousal did not moderate the relationship between condition and craving, coping motives were the most common reasons cited for wanting to use cannabis and were reported more among those in the social interaction task. These experimental results uniquely add to a growing literature suggesting the importance of elevated state social anxiety (especially among those with social anxiety disorder) in cannabis use vulnerability processes. © The Author(s) 2016.
Hindocha, Chandni; Lawn, Will; Freeman, Tom P; Curran, H Valerie
Cannabis and tobacco are often smoked simultaneously in joints, and this practice may increase the risks of developing tobacco and/or cannabis use disorders. Currently, there is no human experimental research on how these drugs interact on addiction-related measures. This study aimed to investigate how cannabis and tobacco, each alone and combined together in joints, affected individuals' demand for cannabis puffs and cigarettes, explicit liking of drug and non-drug-related stimuli and craving. A double-blind, 2 (active cannabis, placebo cannabis) × 2 (active tobacco, placebo tobacco) crossover design was used with 24 non-dependent cannabis and tobacco smokers. They completed a pleasantness rating task (PRT), a marijuana purchase task (MPT) and a cigarette purchase task (CPT) alongside measures of craving pre- and post-drug administration. Relative to placebo cannabis, active cannabis reduced liking of cannabis-associated stimuli and increased response time to all stimuli except cigarette-related stimuli. Relative to placebo cannabis, active cannabis decreased demand for cannabis puffs (trends for breakpoint and elasticity) and cigarettes (breakpoint, P max , O max ) on several characteristics of the purchase tasks. We found no evidence that active tobacco, both alone or combined with cannabis, had an effect on liking, demand or craving. Acutely, cannabis reduced liking of cannabis-related stimuli and demand for cannabis itself. Acute cannabis also reduced demand for cigarettes on the CPT. Acute tobacco administration did not affect demand or pleasantness ratings for cigarettes themselves or cannabis. In non-dependent cannabis and tobacco co-users, tobacco did not influence the rewarding effects of cannabis.
Hemachandra, Dilini; McKetin, Rebecca; Cherbuin, Nicolas; Anstey, Kaarin J
Case reports and hospital-based case-control studies suggest that cannabis use may increase the risk of stroke. We examined the risk of non-fatal stroke or transient ischemic attack (TIA) among cannabis users in the general community. A general population survey of Australians aged 20-24 years (n=2,383), 40-44 years (n=2,525) and 60-64 years (n=2,547) was used to determine the odds of lifetime stroke or TIA among participants who had smoked cannabis in the past year while adjusting for other stroke risk factors. There were 153 stroke/TIA cases (2.1%). After adjusting for age cohort, past year cannabis users (n=1,043) had 3.3 times the rate of stroke/TIA (95% CI 1.8-6.3, pcannabis weekly or more often (IRR 4.7, 95% CI 2.1-10.7) with no elevation among participants who used cannabis less often. Heavy cannabis users in the general community have a higher rate of non-fatal stroke or transient ischemic attack than non-cannabis users. © 2015 Public Health Association of Australia.
McCrystal, Patrick; Winning, Kerry
At the beginning of 2004 the UK government downgraded the legal status of cannabis from a Class B to a Class C drug. Following a review of this decision two years later, cannabis remained a Class C substance--which for some contrasted with the potential harmful social and health effects associated with its use, particularly for young people. These…
Monney, Grégoire; Penzenstadler, Louise; Dupraz, Olivia; Etter, Jean-François; Khazaal, Yasser
The aim of this study was to describe the characteristics of cannabis users and their levels of satisfaction with Stop-cannabis, an app intended for cannabis users who want to stop or reduce their cannabis use or prevent relapse. A cross-sectional online survey was administered to users of Stop-cannabis, a French-language app for iOS and Android devices. All app users were invited to participate in the survey via a message sent to the app. For hundred and eighty-two users answered the survey. The app was used daily by 348 of the participants (around 70%). More than 80% of participants (397) considered the app to have helped them "a little" or "a lot" to stop or reduce cannabis consumption. Most of the users' suggestions were related to the number or the quality of the messages sent by, or displayed in, the app. This pilot study supports the feasibility of such an app and its perceived usefulness. A self-selection bias, however, limits the conclusions of the study. The efficacy of the app should be evaluated in a randomized controlled trial.
Full Text Available Objective: The aim of this study was to describe the characteristics of cannabis users and their levels of satisfaction with Stop-cannabis, an app intended for cannabis users who want to stop or reduce their cannabis use or prevent relapse. Methods: A cross-sectional online survey was administered to users of Stop-cannabis, a French-language app for iOS and Android devices. All app users were invited to participate in the survey via a message sent to the app. Results: For hundred and eighty-two users answered the survey. The app was used daily by 348 of the participants (around 70%. More than 80% of participants (397 considered the app to have helped them a little or a lot to stop or reduce cannabis consumption. Most of the users’ suggestions were related to the number or the quality of the messages sent by, or displayed in, the app.Conclusion: This pilot study supports the feasibility of such an app and its perceived usefulness. A self-selection bias however limits the conclusions of the study. The efficacy of the app should be evaluated in a randomized controlled trial.
Fischer, Benedikt; Dawe, Meghan; Mcguire, Fraser; Shuper, Paul A; Jones, Wayne; Rudzinski, Katherine; Rehm, Jurgen
Aims: Assess key cannabis use, risk and outcome characteristics among high-frequency cannabis users within a university student sample in Toronto, Canada. Methods: N = 134 active universities students (ages of 18-28) using cannabis at least three times per week were recruited by mass advertisement, telephone-screened and anonymously assessed by an…
There is abundant literature on the impact of law enforcement on cannabis markets, but scant literature on the effects of law enforcement on cannabis users. This study undertook a qualitative exploration of police crackdowns as a form of structural violence and examined their impact on the well-being of street cannabis users in a Nigerian city. The study was qualitative and descriptive. It was carried out in Uyo, southern Nigeria. Ninety-seven (97) frequent cannabis users (78 males and 19 females) took part. They were aged between 21 and 34 years and recruited from 11 cannabis hot-points in the city. Data were collected through in-depth, individual interviews, conducted over six-months. Data analysis was thematic and data-driven, involving identifying themes, assigning codes, revising codes and verification by independent qualitative methodology experts. Police crackdowns are commonly experienced by street cannabis users. These do not reduce cannabis use, but displace cannabis markets. Crackdowns are associated with police brutality, confiscation of funds, drugs and belongings, stigma and discrimination, arrest and incarceration, which impacts negatively on the health, livelihoods and well-being of cannabis users. Cannabis users try to escape arrest by running from police, disposing of cannabis, disguising themselves and, when caught, bribing officers to secure release. Crackdowns constitute a form of structural violence in the everyday life of cannabis users, and have negative effects on their health and social and economic well-being. Cannabis use should be decriminalized de facto and arrested users directed to treatment and skills training programmes. Treatment and social services for users should be expanded and legal aid interventions should be mounted to support users in addressing discriminatory practices and human rights violations. Copyright © 2018 Elsevier B.V. All rights reserved.
Pledger, Megan; Martin, Greg; Cumming, Jacqueline
To explore the characteristics of medicinal and non-medicinal cannabis users, and the conditions that were treated with cannabis. The data comes from the New Zealand Health Survey 2012/2013, which sampled 13,009 people, aged 15+ years, living in private or non-private dwellings in New Zealand. Participants self-reported cannabis use and were put into groups: 1) non-users; 2) ex-users; 3) last year users-non-medicinal; 4) last-year users-medicinal. Prevalence was reported for the major demographic subgroups; sex, age and ethnicity. Regression models were then used to find associations between demographic characteristics and cannabis use for groups 3 and 4. About five percent (4.6%, 95% CI 4.1-5.1) of those aged 15+ report using cannabis medicinally. This use was associated with being male, younger, less well-educated and relatively poor. While Māori have the highest prevalence of medicinal use, European NZ/Others make up 67.9% (95% CI 62.7-72.6) of medicinal users. Reported medicinal use was associated with reported conditions that were typically hard to manage: pain, anxiety/nerves and depression. Medicinal users were more likely to report chronic pain and pain interfering, moderately or more, with housework and other work.
Carey, Susan E; Nestor, Liam; Jones, Jennifer; Garavan, Hugh; Hester, Robert
The chronic use of cannabis has been associated with error processing dysfunction, in particular, hypoactivity in the dorsal anterior cingulate cortex (dACC) during the processing of cognitive errors. Given the role of such activity in influencing post-error adaptive behaviour, we hypothesised that chronic cannabis users would have significantly poorer learning from errors. Fifteen chronic cannabis users (four females, mean age=22.40 years, SD=4.29) and 15 control participants (two females, mean age=23.27 years, SD=3.67) were administered a paired associate learning task that enabled participants to learn from their errors, during fMRI data collection. Compared with controls, chronic cannabis users showed (i) a lower recall error-correction rate and (ii) hypoactivity in the dACC and left hippocampus during the processing of error-related feedback and re-encoding of the correct response. The difference in error-related dACC activation between cannabis users and healthy controls varied as a function of error type, with the control group showing a significantly greater difference between corrected and repeated errors than the cannabis group. The present results suggest that chronic cannabis users have poorer learning from errors, with the failure to adapt performance associated with hypoactivity in error-related dACC and hippocampal regions. The findings highlight a consequence of performance monitoring dysfunction in drug abuse and the potential consequence this cognitive impairment has for the symptom of failing to learn from negative feedback seen in cannabis and other forms of dependence. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Han, Benjamin H.; Sherman, Scott; Mauro, Pia M.; Martins, Silvia S.; Rotenberg, James; Palamar, Joseph J.
Background and Aims The ageing US population is providing an unprecedented population of older adults who use recreational drugs. We aimed to estimate the trends in the prevalence of past-year use of cannabis, describe the patterns and attitudes and determine correlates of cannabis use by adults age 50 years and older. Design Secondary analysis of the National Survey on Drug Use and Health survey from 2006 to 2013, a cross-sectional survey given to a nationally representative probability sample of populations living in US households. Setting USA. Participants A total of 47 140 survey respondents aged ≥ 50 years. Measures Estimates and trends of past-year use of cannabis. Findings The prevalence of past-year cannabis use among adults aged ≥ 50 increased significantly from 2006/07 to 2012/13, with a 57.8% relative increase for adults aged 50–64 (linear trend P aged ≥ 65 (linear trend P = 0.002). When combining data from 2006 to 2013, 6.9% of older cannabis users met criteria for cannabis abuse or dependence, and the majority of the sample reported perceiving no risk or slight risk associated with monthly cannabis use (85.3%) or weekly use (79%). Past-year users were more likely to be younger, male, non-Hispanic, not have multiple chronic conditions and use tobacco, alcohol or other drugs compared with non-past-year cannabis users. Conclusions The prevalence of cannabis use has increased significantly in recent years among US adults aged ≥ 50 years. PMID:27767235
Pacek, Lauren R; Mauro, Pia M; Martins, Silvia S
Cannabis is one of the most widely used psychoactive substances in the United States (U.S.). Perceived risk of use is associated with substance use; the recent debate surrounding medicalization and legalization of cannabis in the U.S. has the potential to impact perceived risk of use. Recent estimates are needed to assess temporal changes in, and identify correlates of, perceived risk of cannabis use. Utilizing data from the 2002-2012 survey years of the National Survey on Drug Use and Health, chi-squared statistics and logistic regression were used to describe temporal changes in perceived risk of regular cannabis use (i.e., once or twice a week), to explore correlates of perceived risk, and to report frequency of cannabis use. Between 2002 and 2012, perceived great risk of regular cannabis use varied significantly overall (p race/ethnicity; age 50+; and family income of $20,000-49,999. Characteristics associated with decreased odds of perceived great risk included: ages 12-17 and 18-25; high school education or greater; total family income of $75,000+; past year non-daily and daily cannabis use; and survey years 2008-2012. Findings characterize trends of perceived risk of regular cannabis use, and past year non-daily and daily cannabis use. Longitudinal studies of the influence of legal status of cannabis at the state-level are needed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Terzic Supic, Zorica; Santric Milicevic, Milena; Sbutega, Isidora; Vasic, Vladimir
Adolescence is transitional stage of physical and mental human development occuring between childhood and adult life. Social interactions and environmental factors together are important predictors of adolescent cannabis use. This study aimed to examine the relationship between the social determinants and adolescents behavior with cannabis consumption. A cross sectional study as part of the European School Survey Project on Alcohol and other Drugs was conducted among 6.150 adolescents aged 16 years in three regions of Serbia, and three types of schools (gymnasium, vocational - professional, and vocational - handicraft) during May - June 2008. A multivariate logistic regression analysis was carried out to obtain adjusted odds ratios with 95% confidence intervals in which the dependent variable was cannabis consumption non-user and user. Among 6.7% of adolescents who had tried cannabis at least one in their lives, boys were more involved in cannabis use than girls, especially boys from gymnasium school. Well off family, lower education of mother, worse relations with parents were significantly associated with cannabis use (P related to cannabis use (P study confirmed the importance of family relationship development. Drug use preventive programmes should include building interpersonal trust in a family lifecycle and school culture.
Full Text Available Large shifts in medical, recreational, and illicit cannabis consumption in the United States have implications for personalizing treatment and prevention programs to a wide variety of populations. As such, considerable research has investigated clinical presentations of cannabis users in clinical and population-based samples. Studies leveraging big data, social media, and social network analysis have emerged as a promising mechanism to generate timely insights that can inform treatment and prevention research. This study extends a novel method called stochastic block modeling to derive communities of cannabis consumers as part of a complex social network on Twitter. A set of examples illustrate how this method can ascertain candidate samples of medical, recreational, and illicit cannabis users. Implications for research planning, intervention design, and public health surveillance are discussed.
The research presented in this thesis focused on the effects of cannabis on mental functions and the brain. Specifically, the investigation aimed at exploring how cannabis affects creative thinking, awareness of errors, and the neurotransmitter dopamine among regular cannabis users. It was
Crane, Natania A; Schuster, Randi Melissa; Mermelstein, Robin J; Gonzalez, Raul
Earlier initiation of cannabis use is associated with poorer neuropsychological functioning across several domains. Given well-documented sex differences in neuromaturation during adolescence, initiation of cannabis use during this time may affect neuropsychological functioning differently for males and females. In the current study, we examined sex differences in the relationship between age of initiated cannabis use and neuropsychological performance after controlling for amount of lifetime cannabis use in 44 male and 25 female young adult cannabis users. We found that an earlier age of initiated use was related to poorer episodic memory, especially immediate recall, in females, but not in males. On the other hand, we found that, surprisingly, an earlier age of initiated use was associated with better decision making overall. However, exploratory analyses found sex-specific factors associated with decision making and age of initiated use, specifically that attention-deficit/hyperactivity disorder (ADHD) symptoms in females may drive the relationship between an earlier age of initiated use and better decision making. Further, an earlier age of initiated use was associated with less education, a lower IQ, and fewer years of mother's education for females, but more lifetime cannabis use for males. Taken together, our findings suggest there are sex differences in the associations between age of initiated cannabis use and neuropsychological functioning. The current study provides preliminary evidence that males and females may have different neuropsychological vulnerabilities that place them at risk for initiating cannabis use and continued cannabis use, highlighting the importance of examining the impact of cannabis on neuropsychological functioning separately for males and females.
Thijssen, Sandra; Rashid, Barnaly; Gopal, Shruti; Nyalakanti, Prashanth; Calhoun, Vince D; Kiehl, Kent A
Cannabis and alcohol are believed to have widespread effects on the brain. Although adolescents are at increased risk for substance use, the adolescent brain may also be particularly vulnerable to the effects of drug exposure due to its rapid maturation. Here, we examined the association between cannabis and alcohol use duration and resting-state functional connectivity in a large sample of male juvenile delinquents. The present sample was drawn from the Southwest Advanced Neuroimaging Cohort, Youth sample, and from a youth detention facility in Wisconsin. All participants were scanned at the maximum-security facilities using The Mind Research Network's 1.5T Avanto SQ Mobile MRI scanner. Information on cannabis and alcohol regular use duration was collected using self-report. Resting-state networks were computed using group independent component analysis in 201 participants. Associations with cannabis and alcohol use were assessed using Mancova analyses controlling for age, IQ, smoking and psychopathy scores in the complete case sample of 180 male juvenile delinquents. No associations between alcohol or cannabis use and network spatial maps were found. Longer cannabis use was associated with decreased low frequency power of the default mode network, the executive control networks (ECNs), and several sensory networks, and with decreased functional network connectivity. Duration of alcohol use was associated with decreased low frequency power of the right frontoparietal network, salience network, dorsal attention network, and several sensory networks. Our findings suggest that adolescent cannabis and alcohol use are associated with widespread differences in resting-state time course power spectra, which may persist even after abstinence. Copyright © 2017 Elsevier B.V. All rights reserved.
Chan, Gary C K; Hall, Wayne; Freeman, Tom P; Ferris, Jason; Kelly, Adrian B; Winstock, Adam
Recent reports suggest an increase in use of extremely potent cannabis concentrates such as Butane Hash Oil (BHO) in some developed countries. The aims of this study were to examine the characteristics of BHO users and the effect profiles of BHO. Anonymous online survey in over 20 countries in 2014 and 2015. Participants aged 18 years or older were recruited through onward promotion and online social networks. The overall sample size was 181,870. In this sample, 46% (N=83,867) reported using some form of cannabis in the past year, and 3% reported BHO use (n=5922). Participants reported their use of 7 types of cannabis in the past 12 months, the source of their cannabis, reasons for use, use of other illegal substances, and lifetime diagnosis for depression, anxiety and psychosis. Participants were asked to rate subjective effects of BHO and high potency herbal cannabis. Participants who reported a lifetime diagnosis of depression (OR=1.15, p=0.003), anxiety (OR=1.72, pcannabis. BHO users also reported stronger negative effects and less positive effects when using BHO than high potency herbal cannabis (pcannabis. Copyright © 2017. Published by Elsevier B.V.
Bloor, R.; Wang, T. S.; Španěl, Patrik; Smith, D.
Roč. 103, č. 10 (2008), s. 1671-1677 ISSN 0965-2140 Institutional research plan: CEZ:AV0Z40400503 Keywords : ammonia * cannabis * respiratory Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.244, year: 2008
Laprevote, Vincent; Bon, Laura; Krieg, Julien; Schwitzer, Thomas; Bourion-Bedes, Stéphanie; Maillard, Louis; Schwan, Raymund
Both acute and regular cannabis use affects the functioning of the brain. While several studies have demonstrated that regular cannabis use can impair the capacity to synchronize neural assemblies during specific tasks, less is known about spontaneous brain activity. This can be explored by measuring EEG complexity, which reflects the spontaneous variability of human brain activity. A recent study has shown that acute cannabis use can affect that complexity. Since the characteristics of cannabis use can affect the impact on brain functioning, this study sets out to measure EEG complexity in regular cannabis users with or without dependence, in comparison with healthy controls. We recruited 26 healthy controls, 25 cannabis users without cannabis dependence and 14 cannabis users with cannabis dependence, based on DSM IV TR criteria. The EEG signal was extracted from at least 250 epochs of the 500ms pre-stimulation phase during a visual evoked potential paradigm. Brain complexity was estimated using Lempel-Ziv Complexity (LZC), which was compared across groups by non-parametric Kruskall-Wallis ANOVA. The analysis revealed a significant difference between the groups, with higher LZC in participants with cannabis dependence than in non-dependent cannabis users. There was no specific localization of this effect across electrodes. We showed that cannabis dependence is associated to an increased spontaneous brain complexity in regular users. This result is in line with previous results in acute cannabis users. It may reflect increased randomness of neural activity in cannabis dependence. Future studies should explore whether this effect is permanent or diminishes with cannabis cessation. Copyright © 2017 Elsevier B.V. and ECNP. All rights reserved.
Walker, Denise D; Stephens, Robert; Roffman, Roger; Demarce, Josephine; Lozano, Brian; Towe, Sheri; Berg, Belinda
Cannabis use adversely affects adolescents and interventions that are attractive to adolescents are needed. This trial compared the effects of a brief motivational intervention for cannabis use with a brief educational feedback control and a no-assessment control. Participants were randomized into one of three treatment conditions: Motivational Enhancement Therapy (MET), Educational Feedback Control (EFC), or Delayed Feedback Control (DFC). Those who were assigned to MET and EFC were administered a computerized baseline assessment immediately following randomization and completed assessments at the 3- and 12-month follow-up periods. Participants in the DFC condition were not assessed until the 3-month follow-up. Following the completion of treatment sessions, all participants were offered up to four optional individual treatment sessions aimed at cessation of cannabis use. The research was conducted in high schools in Seattle, Washington. The participant s included 310 self-referred adolescents who smoked cannabis regularly. The main outcome measures included days of cannabis use, associated negative consequences, and engagement in additional treatment. At the 3-month follow-up, participants in both the MET and EFC conditions reported significantly fewer days of cannabis use and negative consequences compared to those in the DFC. The frequency of cannabis use was less in MET relative to EFC at 3 months, but it did not translate to differences in negative consequences. Reductions in use and problems were sustained at 12 months, but there were no differences between MET and EFC interventions. Engagement in additional treatment was minimal and did not differ by condition. Brief interventions can attract adolescent cannabis users and have positive impacts on them, but the mechanisms of the effects are yet to be identified. (c) 2011 APA, all rights reserved.
Thames, April D; Arbid, Natalie; Sayegh, Philip
With the recent debates over marijuana legalization and increases in use, it is critical to examine its role in cognition. While many studies generally support the adverse acute effects of cannabis on neurocognition, the non-acute effects remain less clear. The current study used a cross-sectional design to examine relationships between recent and past cannabis use on neurocognitive functioning in a non-clinical adult sample. One hundred and fifty-eight participants were recruited through fliers distributed around local college campuses and the community. All participants completed the Brief Drug Use History Form, the Structured Clinical Interview for DSM-IV Disorders, and neurocognitive assessment, and underwent urine toxicology screening. Participants consisted of recent users (n=68), past users (n=41), and non-users (n=49). Recent users demonstrated significantly (pcannabis use in the last 4 weeks was negatively associated with global neurocognitive performance and all individual cognitive domains. Similarly, amount of daily cannabis use was negatively associated with global neurocognitive performance and individual cognitive domains. Our results support the widespread adverse effects of cannabis use on neurocognitive functioning. Although some of these adverse effects appear to attenuate with abstinence, past users' neurocognitive functioning was consistently lower than non-users. Copyright © 2014 Elsevier Ltd. All rights reserved.
Filbey, Francesca M; Dunlop, Joseph; Ketcherside, Ariel; Baine, Jessica; Rhinehardt, Tyler; Kuhn, Brittany; DeWitt, Sam; Alvi, Talha
Although there is emergent evidence illustrating neural sensitivity to cannabis cues in cannabis users, the specificity of this effect to cannabis cues as opposed to a generalized hyper-sensitivity to hedonic stimuli has not yet been directly tested. Using fMRI, we presented 53 daily, long-term cannabis users and 68 non-using controls visual and tactile cues for cannabis, a natural reward, and, a sensory-perceptual control object to evaluate brain response to hedonic stimuli in cannabis users. The results showed an interaction between group and reward type such that the users had greater response during cannabis cues relative to natural reward cues (i.e., fruit) in the orbitofrontal cortex, striatum, anterior cingulate gyrus, and ventral tegmental area compared to non-users (cluster-threshold z = 2.3, P brain-behavior correlations between neural response to cannabis cues in fronto-striatal-temporal regions and subjective craving, marijuana-related problems, withdrawal symptoms, and levels of THC metabolites (cluster-threshold z = 2.3, P brain response to cannabis cues in long-term cannabis users that are above that of response to natural reward cues. These observations are concordant with incentive sensitization models suggesting sensitization of mesocorticolimbic regions and disruption of natural reward processes following drug use. Although the cross-sectional nature of this study does not provide information on causality, the positive correlations between neural response and indicators of cannabis use (i.e., THC levels) suggest that alterations in the reward system are, in part, related to cannabis use. Hum Brain Mapp 37:3431-3443, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
Dunlop, Joseph; Ketcherside, Ariel; Baine, Jessica; Rhinehardt, Tyler; Kuhn, Brittany; DeWitt, Sam; Alvi, Talha
Abstract Although there is emergent evidence illustrating neural sensitivity to cannabis cues in cannabis users, the specificity of this effect to cannabis cues as opposed to a generalized hyper‐sensitivity to hedonic stimuli has not yet been directly tested. Using fMRI, we presented 53 daily, long‐term cannabis users and 68 non‐using controls visual and tactile cues for cannabis, a natural reward, and, a sensory‐perceptual control object to evaluate brain response to hedonic stimuli in cannabis users. The results showed an interaction between group and reward type such that the users had greater response during cannabis cues relative to natural reward cues (i.e., fruit) in the orbitofrontal cortex, striatum, anterior cingulate gyrus, and ventral tegmental area compared to non‐users (cluster‐threshold z = 2.3, P cannabis cues in fronto‐striatal‐temporal regions and subjective craving, marijuana‐related problems, withdrawal symptoms, and levels of THC metabolites (cluster‐threshold z = 2.3, P cannabis cues in long‐term cannabis users that are above that of response to natural reward cues. These observations are concordant with incentive sensitization models suggesting sensitization of mesocorticolimbic regions and disruption of natural reward processes following drug use. Although the cross‐sectional nature of this study does not provide information on causality, the positive correlations between neural response and indicators of cannabis use (i.e., THC levels) suggest that alterations in the reward system are, in part, related to cannabis use. Hum Brain Mapp 37:3431–3443, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc. PMID:27168331
Cannabis and ecstasy are among the most widely used illicit drugs in the world. However, there are substantial concerns about their neurotoxic potential for brain and brain function. Despite previous research, some crucial questions regarding the causality, course and clinical relevance have
Zwenger, S R
Human papilloma virus (HPV) has many known strains, two of the most well studied perhaps being the high-risk types 16 and 18. These strains have attracted more interest because they are known to disrupt tumour-suppressor genes that control the cell cycle, rendering those genes less effective at keeping cell division in check.Within the last decade, an increase in oral hpv-linked cancers of the throat and tongue has been attributed to exposure and contraction of hpv through oral sex, most notably in younger people. An understudied and arguably equal contributor to oral hpv infection might be indirect contact with an infected person. Presented here is a brief but important perspective on the relationship between cannabis use and oral cancer. The development of oral cancer is not a result of smoking cannabis per se; rather, it is hypothesized to be a result of contracting hpv through various forms of sharing and passing joints and other smoking apparatuses. Therefore, it is hypothesized that bogarting (and not passing) joints might decrease oral hpv among cannabis smokers. Future research should therefore investigate the prevalence of oral hpv in cannabis smokers to better understand its epidemiology.
Sodos, Louise M; Hirst, Rayna B; Watson, Jessica; Vaughn, Dylan
The experimenter expectancy effect confound remains largely unexplored in neuropsychological research and has never been investigated among cannabis users. This study investigated whether examiner expectancies of cannabis user status affected examinees' neuropsychological performance. Participants included 41 cannabis users and 20 non-users. Before testing, examiners who were blind to participant user status privately rated whether they believed the examinee was a cannabis user or non-user. Examiners then administered a battery of neuropsychological and performance validity measures. Multiple regression analyses compared performance between examinees judged as cannabis users (n = 37) and those judged as non-users (n = 24). Examiners' judgments of cannabis users were 75% accurate; judgments of non-users were at chance. After controlling for age, gender, and actual user status, examiner judgments of cannabis user status predicted performance on two measures (California Verbal Learning Test-II, and Trail Making Test B; p users obtained lower scores than those judged as non-users. Examiners' judgments of cannabis user status predicted performance even after controlling for actual user status, indicating vulnerability to examiner expectancy effects. These findings have important implications for both research and clinical settings, as scores may partially reflect examiners' expectations regarding cannabis effects rather than participants' cognitive abilities. These results demonstrate the need for expectancy effect research in the neuropsychological assessment of all populations, not just cannabis users. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: firstname.lastname@example.org.
Loflin, Mallory; Babson, Kimberly; Browne, Kendall; Bonn-Miller, Marcel
The Cannabis Use Disorders Identification Test-Revised (CUDIT-R) is an 8-item measure used to screen for cannabis use disorders (CUD). Despite widespread use of the tool, assessments of the CUDIT-R's validity in subpopulations are limited. The current study tested the structural validity and internal consistency of one of the most widely used screening measures for CUD (i.e., CUDIT-R) among a sample of military veterans who use cannabis for medicinal purposes. The present study used confirmatory factor analysis (CFA) to test the internal consistency and validity of the single-factor structure of the original screener among a sample of veterans who use cannabis for medicinal purposes (n = 90 [90% male]; M age = 55.31, SD = 15.37). Measures included demographics and the CUDIT-R, obtained from the baseline assessment of an ongoing longitudinal study. The CFA revealed that the single-factor model previously validated in recreational using samples only accounted for 38.34% of total variance in responses on the CUDIT-R (χ 2 = 66.09, df = 28, p medicinal cannabis and other subpopulations of cannabis users.
Morean, Meghan E; Lipshie, Noah; Josephson, Margo; Foster, Dawn
Given limited extant research, we assessed the use of portable, battery-powered cannabis vaporizers by adult e-cigarette users. 522 adult vapers completed an online survey. Demographics; lifetime and past-month cannabis vaporization via e-cigarettes/vape-pens; preferences for hash oil, D-9-tetrahydrocannabinol (THC) wax, or dried buds; and cannabis vaporization beliefs and motives were examined. Demographics, age of e-cigarette onset, e-cigarette use frequency, state-level legal status of cannabis, cannabis vaping beliefs/motives, and impulsivity were examined as predictors of lifetime cannabis vaporization, past-month cannabis vaporization, and cannabis vaping frequency. E-cigarette users reported lifetime (17.8%) and past-month (11.5%) cannabis vaporization. Vapers preferred hash oil (LT/PM 45.5/47.5%), THC wax (15.2/32.2%), and dried buds (39.4/35.6%). Motivations to vape cannabis included: it tastes better (39.3/37.9%), is healthier (42.9/39.7%), is easier to conceal/hide (35.7/46.6%), does not smell as strong (42.9/39.7%), is more convenient (42.9/27.6%), and produces a stronger/better high (58.1/40.7%) than smoking cannabis. Lifetime and past-month cannabis vaporization, respectively, were associated with initiating e-cigarette use at an earlier age (odds ratio (OR) = 0.09/0.88), being impulsive (OR = 2.25/3.23), having poor self-control (OR = 2.23/1.85), and vaporizing cannabis because it is easier to conceal/hide (OR = 2.45/2.48) or is more convenient than smoking cannabis (OR = 5.02/2.83). Frequency of vaping cannabis was associated with heavier e-cigarette use (η p 2 = 0.10) and impulsivity (η p 2 = 0.09). Adult e-cigarette users are vaporizing cannabis using e-cigarettes/vape-pens. Efforts to curb cannabis vaporization may benefit from targeting impulsivity in users and regulating device features that facilitate or promote convenient, inconspicuous cannabis use.
Haug, Nancy A; Padula, Claudia B; Sottile, James E; Vandrey, Ryan; Heinz, Adrienne J; Bonn-Miller, Marcel O
Medical cannabis is increasingly being used for a variety of health conditions as more states implement legislation permitting medical use of cannabis. Little is known about medical cannabis use patterns and motives among adults across the lifespan. The present study examined data collected at a medical cannabis dispensary in San Francisco, California. Participants included 217 medical cannabis patients who were grouped into age-defined cohorts (younger: 18-30, middle-aged: 31-50, and older: 51-72). The age groups were compared on several measures of cannabis use, motives and medical conditions using one-way ANOVAs, chi-square tests and linear regression analyses. All three age groups had similar frequency of cannabis use over the past month; however, the quantity of cannabis used and rates of problematic cannabis use were higher among younger users relative to middle-aged and older adults. The association between age and problematic cannabis use was moderated by age of regular use initiation such that earlier age of regular cannabis use onset was associated with more problematic use in the younger users, but not among older users. Middle-aged adults were more likely to report using medical cannabis for insomnia, while older adults were more likely to use medical cannabis for chronic medical problems such as cancer, glaucoma and HIV/AIDS. Younger participants reported cannabis use when bored at a greater rate than middle-aged and older adults. Findings suggest that there is an age-related risk for problematic cannabis use among medical cannabis users, such that younger users should be monitored for cannabis use patterns that may lead to deleterious consequences. Copyright © 2017 Elsevier Ltd. All rights reserved.
Haug, Nancy A.; Padula, Claudia B.; Sottile, James E.; Vandrey, Ryan; Heinz, Adrienne J.; Bonn-Miller, Marcel O.
Introduction Medical cannabis is increasingly being used for a variety of health conditions as more states implement legislation permitting medical use of cannabis. Little is known about medical cannabis use patterns and motives among adults across the lifespan. Methods The present study examined data collected at a medical cannabis dispensary in San Francisco, California. Participants included 217 medical cannabis patients who were grouped into age-defined cohorts (younger: 18–30, middle-aged: 31–50, and older: 51–72). The age groups were compared on several measures of cannabis use, motives and medical conditions using one-way ANOVAs, chi-square tests and linear regression analyses. Results All three age groups had similar frequency of cannabis use over the past month; however, the quantity of cannabis used and rates of problematic cannabis use were higher among younger users relative to middle-aged and older adults. The association between age and problematic cannabis use was moderated by age of regular use initiation such that earlier age of regular cannabis use onset was associated with more problematic use in the younger users, but not among older users. Middle-aged adults were more likely to report using medical cannabis for insomnia, while older adults were more likely to use medical cannabis for chronic medical problems such as cancer, glaucoma and HIV/AIDS. Younger participants reported cannabis use when bored at a greater rate than middle-aged and older adults. Conclusions Findings suggest that there is an age-related risk for problematic cannabis use among medical cannabis users, such that younger users should be monitored for cannabis use patterns that may lead to deleterious consequences. PMID:28340421
Lorenzetti, V.; Cousijn, J.; Preedy, V.R.
Cannabis use disorders (CUDs) affect 13.1. million individuals worldwide and represent the most vulnerable portion of regular cannabis users. Neuroanatomical alterations in the brain may mediate the adverse outcomes of CUDs. We reviewed findings from 16 structural neuroimaging studies of gray matter
J R, Alameda-Bailén; M P, Salguero-Alcañiz; A, Merchán-Clavellino; S, Paíno-Quesada
The relationship between the use of cannabis and the decision-making processes was explored. A computerized version of the Iowa Gambling Task (Cards Software) in its normal and reverse version was used, and the Prospect Valence Learning (PVL) model, which characterize the process of decision-making based on the parameters: Recency, Consistency, Loss aversion and Utility shape, was applied. Seventy-three cannabis consumers and a control group with 73 nonconsumers participated in the study. In the normal mode, subjects in the control group scored higher than cannabis consumers. Both groups showed consistent responses and aversion to loss. Nonconsumers showed greater influence of the gain-loss frequency, while consumers were more influenced by the magnitude of the gain-loss. The influence of immediate choices was higher among consumers who showed a quick oblivion while in the control group this process was more gradual. In the reverse mode, task performance was better among control group participants. Both groups showed consistency, loss aversion, more influenced by the magnitude of the gain-loss, and low influence of immediate elections. The results show the relationship between drug use and the decision-making processes, being consistent with the results obtained in other studies where consumers had worse results than control group. Moreover, the PVL parameters allow to adequately characterize decision-making. This confirms the relationship between drug use and decision-making by either the vulnerability prior to consumption or the neurotoxicity of drugs.
Cermak, Timmen L
This article begins with a case vignette exemplifying the common clinical problem of heavy marijuana users. The epidemiology and basic science underlying cannabis dependence is outlined, followed by clinical strategies for basing a therapeutic alliance on known research findings and using motivational interviewing to deal with typical patterns of denial.
Hasan O. Keles
Full Text Available Intoxication from cannabis impairs cognitive performance, in part due to the effects of Δ9-tetrahydrocannabinol (THC, the primary psychoactive compound in cannabis on prefrontal cortex (PFC function. However, a relationship between impairment in cognitive functioning with THC administration and THC-induced change in hemodynamic response has not been demonstrated. We explored the feasibility of using functional near-infrared spectroscopy (fNIRS to examine the functional changes of the human PFC associated with cannabis intoxication and cognitive impairment. Eighteen adult regular cannabis users (final sample, n = 13 performed a working memory task (n-back during fNIRS recordings, before and after receiving a single dose of oral synthetic THC (dronabinol; 20–50 mg. Functional data were collected using a continuous-wave NIRS device, in which 8 Sources and 7 detectors were placed on the forehead, resulting in 20 channels covering PFC regions. Physiological changes and subjective intoxication measures were collected. We found a significant increase in the oxygenated hemoglobin (HbO concentration after THC administration in several channels on the PFC during both the high working memory load (2-back and the low working memory load (0-back condition. The increased HbO response was accompanied by a trend toward an increased number of omission errors after THC administration. The current study suggests that cannabis intoxication is associated with increases in hemodynamic blood flow to the PFC, and that this increase can be detected with fNIRS.
Palali, A. (Ali); Ours, Jan
textabstractWe investigate the determinants of the support for cannabis legalization finding a causal effect of personal experience with cannabis use. Current and past cannabis users are more in favor of legalization. We relate this finding to self-interest and inside information about potential dangers of cannabis. While the self-interest effect is not very surprising, the effect of inside information suggests that cannabis use is not as harmful as cannabis users originally thought it was be...
de Gee, Elisabeth A.; Verdurmen, Jacqueline E. E.; Bransen, Els; de Jonge, Jannet M.; Schippers, Gerard M.
Evidence for negative effects of early-onset cannabis use has led to a need for effective interventions targeting adolescent cannabis users. A randomized controlled trial of an Australian two-session intervention based on motivational interviewing (the ACCU, or Weed-Check in Dutch) was replicated in
Fridberg, Daniel J; Queller, Sarah; Ahn, Woo-Young; Kim, Woojae; Bishara, Anthony J; Busemeyer, Jerome R; Porrino, Linda; Stout, Julie C
Chronic cannabis users are known to be impaired on a test of decision-making, the Iowa Gambling Task (IGT). Computational models of the psychological processes underlying this impairment have the potential to provide a rich description of the psychological characteristics of poor performers within particular clinical groups. We used two computational models of IGT performance, the Expectancy-Valence Learning model (EVL) and the Prospect-Valence Learning model (PVL), to assess motivational, memory, and response processes in 17 chronic cannabis abusers and 15 control participants. Model comparison and simulation methods revealed that the PVL model explained the observed data better than the EVL model. Results indicated that cannabis abusers tended to be under-influenced by loss magnitude, treating each loss as a constant and minor negative outcome regardless of the size of the loss. In addition, they were more influenced by gains, and made decisions that were less consistent with their expectancies relative to non-using controls.
Cousijn, J.; Wiers, R.W.; Ridderinkhof, K.R.; van den Brink, W.; Veltman, D.J.; Goudriaan, A.E.
Cannabis abuse is related to impairments in a broad range of cognitive functions. However, studies on cannabis abuse in relation to brain structure are sparse and results are inconsistent, probably due to differences in imaging methodology, severity of cannabis abuse, and use of other substances.
Cousijn, Janna; Wiers, Reinout W.; Ridderinkhof, K. Richard; van den Brink, Wim; Veltman, Dick J.; Goudriaan, Anna E.
Cannabis abuse is related to impairments in a broad range of cognitive functions. However, studies on cannabis abuse in relation to brain structure are sparse and results are inconsistent, probably due to differences in imaging methodology, severity of cannabis abuse, and use of other substances.
Vingerhoets, W.A.M.; Koenders, L.; van den Brink, W.P.; Wiers, R.W.; Goudriaan, A.E.; van Amelsvoort, T.; de Haan, L.; Cousijn, J.
Cannabis is the most frequently used illicit drug worldwide, but little is known about the mechanisms underlying continued cannabis use. Cue-reactivity (the physical, psychological, behavioural and neural reaction to substance-related cues) might be related to continued cannabis use. In this 3-year
Blanco-Hinojo, Laura; Pujol, Jesus; Harrison, Ben J; Macià, Dídac; Batalla, Albert; Nogué, Santiago; Torrens, Marta; Farré, Magí; Deus, Joan; Martín-Santos, Rocío
Heavy cannabis use is associated with reduced motivation. The basal ganglia, central in the motivation system, have the brain's highest cannabinoid receptor density. The frontal lobe is functionally coupled to the basal ganglia via segregated frontal-subcortical circuits conveying information from internal, self-generated activity. The basal ganglia, however, receive additional influence from the sensory system to further modulate purposeful behaviors according to the context. We postulated that cannabis use would impact functional connectivity between the basal ganglia and both internal (frontal cortex) and external (sensory cortices) sources of influence. Resting-state functional connectivity was measured in 28 chronic cannabis users and 29 controls. Selected behavioral tests included reaction time, verbal fluency and exposition to affective pictures. Assessments were repeated after one month of abstinence. Cannabis exposure was associated with (1) attenuation of the positive correlation between the striatum and areas pertaining to the 'limbic' frontal-basal ganglia circuit, and (2) attenuation of the negative correlation between the striatum and the fusiform gyrus, which is critical in recognizing significant visual features. Connectivity alterations were associated with lower arousal in response to affective pictures. Functional connectivity changes had a tendency to normalize after abstinence. The results overall indicate that frontal and sensory inputs to the basal ganglia are attenuated after chronic exposure to cannabis. This effect is consistent with the common behavioral consequences of chronic cannabis use concerning diminished responsiveness to both internal and external motivation signals. Such an impairment of the fine-tuning in the motivation system notably reverts after abstinence. © 2016 Society for the Study of Addiction.
Creemers, H E; Harakeh, Z; Dick, D M; Meyers, J; Vollebergh, W A M; Ormel, J; Verhulst, F C; Huizink, A C
The aims of the present study were to determine the direct effect of DRD2 and DRD4, as well as their interaction with parenting (i.e. rejection, overprotection and emotional warmth), on the development of regular alcohol and cannabis use in 1192 Dutch adolescents from the general population. Information was obtained by self-report questionnaires. Perceived rejection, overprotection and emotional warmth were assessed at age 10-12. Regular alcohol and cannabis use were determined at age 15-18 and defined as the consumption of alcohol on 10 or more occasions in the past four weeks, and the use of cannabis on 4 or more occasions in the past four weeks. Models were adjusted for age, sex, parental alcohol or cannabis use, and externalizing behavior. Carrying the A1 allele of the DRD2 TaqIA polymorphism, or the 7 repeat DRD4, was not directly related to regular alcohol or cannabis use. In addition, adolescent carriers of these genetic risk markers were not more susceptible to the influence of less optimal parenting. Main effects for parenting indicated that overprotection increased the risk of regular alcohol use, whereas the risk of cannabis use was enhanced by parental rejection and buffered by emotional warmth. Our findings do not support an association between DRD2/DRD4 and regular alcohol and cannabis use in adolescents. Given the substance-specific influences of rejection, overprotection and emotional warmth, these parenting factors might be promising candidates for prevention work. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
Boileau, Isabelle; Mansouri, Esmaeil; Williams, Belinda; Le Foll, Bernard; Rusjan, Pablo; Mizrahi, Romina; Tyndale, Rachel F.; Huestis, Marilyn A.; Payer, Doris E.; Wilson, Alan A.; Houle, Sylvain; Kish, Stephen J.; Tong, Junchao
Background One of the major mechanisms for terminating the actions of the endocannabinoid anandamide is hydrolysis by fatty acid amide hydrolase (FAAH) and inhibitors of the enzyme were suggested as potential treatment for human cannabis dependence. However, the status of brain FAAH in cannabis use disorder is unknown. Methods Brain FAAH binding was measured with positron emission tomography and [11C]CURB in 22 healthy control subjects and ten chronic, frequent cannabis users during early abstinence. The FAAH genetic polymorphism (rs324420) and blood, urine and hair levels of cannabinoids and metabolites were determined. Results In cannabis users FAAH binding was significantly lower by 14–20% across the brain regions examined as compared to matched control subjects (overall Cohen’s d=0.96). Lower binding was negatively correlated with cannabinoid concentrations in blood and urine and was associated with higher trait impulsiveness. Conclusions Lower FAAH binding levels in the brain may be a consequence of chronic and recent cannabis exposure and could contribute to cannabis withdrawal. This effect should be considered in the development of novel treatment strategies for cannabis use disorder that target FAAH and endocannabinoids. Further studies are needed to examine possible changes in FAAH binding during prolonged cannabis abstinence and whether lower FAAH binding predates drug use. PMID:27345297
Full Text Available Research suggests that daily cannabis users have impaired memory for past events, but it is not clear whether they are also impaired in prospective memory (PM for future events. The present study examined PM in daily cannabis users who were either dependent (n = 18 or non-dependent (n = 18, and compared them with non-using controls (n = 18. The effect of future event simulation (FES on PM performance was also examined. Participants were matched across groups on age, gender, and highest level of education. The virtual week (VW was used to objectively assess PM abilities, both at baseline and following FES. Other measures used were: cannabis use variables, immediate and delayed prose recall, phonemic and category fluency, spot-the-word test (premorbid intelligence, Beck Depression Inventory, Beck Anxiety Inventory, and a measure of schizotypy (Oxford-Liverpool Inventory of Feelings and Experiences: unusual experiences subscale. No group differences were found in PM performance on the VW, and FES did not improve PM performance in any group. Dependent cannabis users scored higher on depression, anxiety, and schizotypy than both other groups with non-dependent cannabis users scoring at a similar level to controls. There were no group differences in alcohol use. Findings suggest that when carefully matched on baseline variables, and not differing in premorbid IQ or alcohol use, young, near-daily cannabis users do not differ from non-using controls in PM performance.
Galindo, Liliana; Moreno, Estefanía; López-Armenta, Fernando; Guinart, Daniel; Cuenca-Royo, Aida; Izquierdo-Serra, Mercè; Xicota, Laura; Fernandez, Cristina; Menoyo, Esther; Fernández-Fernández, José M; Benítez-King, Gloria; Canela, Enric I; Casadó, Vicent; Pérez, Víctor; de la Torre, Rafael; Robledo, Patricia
Cannabinoid CB1 receptors (CB 1 R) and serotonergic 2A receptors (5HT 2A R) form heteromers in the brain of mice where they mediate the cognitive deficits produced by delta-9-tetrahydrocannabinol. However, it is still unknown whether the expression of this heterodimer is modulated by chronic cannabis use in humans. In this study, we investigated the expression levels and functionality of CB 1 R-5HT 2A R heteromers in human olfactory neuroepithelium (ON) cells of cannabis users and control subjects, and determined their molecular characteristics through adenylate cyclase and the ERK 1/2 pathway signaling studies. We also assessed whether heteromer expression levels correlated with cannabis consumption and cognitive performance in neuropsychological tests. ON cells from controls and cannabis users expressed neuronal markers such as βIII-tubulin and nestin, displayed similar expression levels of genes related to cellular self-renewal, stem cell differentiation, and generation of neural crest cells, and showed comparable Na + currents in patch clamp recordings. Interestingly, CB 1 R-5HT 2A R heteromer expression was significantly increased in cannabis users and positively correlated with the amount of cannabis consumed, and negatively with age of onset of cannabis use. In addition, a negative correlation was found between heteromer expression levels and attention and working memory performance in cannabis users and control subjects. Our findings suggest that cannabis consumption regulates the formation of CB 1 R-5HT 2A R heteromers, and may have a key role in cognitive processing. These heterodimers could be potential new targets to develop treatment alternatives for cognitive impairments.
de Sousa Fernandes Perna, Elizabeth B; Theunissen, Eef L; Kuypers, Kim P C; Evers, Elisabeth A; Stiers, Peter; Toennes, Stefan W; Witteman, Jurriaan; van Dalen, Wim; Ramaekers, Johannes G
Drugs of abuse stimulate striatal dopamine release and activate reward pathways. This study examined the impact of alcohol and cannabis marketing on the reward circuit in alcohol and cannabis users while sober and intoxicated. It was predicted that alcohol and cannabis marketing would increase striatal activation when sober and that reward sensitivity would be less during alcohol and cannabis intoxication. Heavy alcohol (n = 20) and regular cannabis users (n = 21) participated in a mixed factorial study involving administration of alcohol and placebo in the alcohol group and cannabis and placebo in the cannabis group. Non-drug users (n = 20) served as between group reference. Brain activation after exposure to alcohol and cannabis marketing movies was measured using functional magnetic resonance imaging and compared between groups while sober and compared with placebo while intoxicated. Implicit alcohol and cannabis cognitions were assessed by means of a single-category implicit association test. Alcohol and cannabis marketing significantly increased striatal BOLD activation across all groups while sober. Striatal activation however decreased during intoxication with alcohol and cannabis. Implicit associations with cannabis marketing cues were significantly more positive in alcohol and cannabis users as compared with non-drug using controls. Public advertising of alcohol or cannabis use elicits striatal activation in the brain's reward circuit. Reduction of marketing would reduce brain exposure to reward cues that motivate substance use. Conversely, elevated dopamine levels protect against the reinforcing potential of marketing. © 2016 Society for the Study of Addiction.
Palali, A.; van Ours, J.C.
We investigate the determinants of the support for cannabis legalizationfinding a causal effect of personal experience with cannabis use. Current and past cannabis users are more in favor of legalization. We relate this to self-interest and inside information about potential dangers of cannabis use.
Creemers, H.E.; Harakeh, Z.; Dick, D.M.; Meyers, J.; Vollebergh, W.A.; Ormel, J.; Verhulst, F.C.; Huizink, A.C.
Aims: The aims of the present study were to determine the direct effect of DRD2 and DRD4, as well as their interaction with parenting (i.e. rejection, overprotection and emotional warmth), on the development of regular alcohol and cannabis use in 1192 Dutch adolescents from the general population.
Creemers, H.E.; Harakeh, Z.; Dick, D.M.; Meyers, J.; Vollebergh, W.A.M.; Ormel, J.; Verhulst, F.C.; Huizink, A.C.
Aims The aims of the present study were to determine the direct effect of DRD2 and DRD4, as well as their interaction with parenting (i.e. rejection, overprotection and emotional warmth), on the development of regular alcohol and cannabis use in 1192 Dutch adolescents from the general population.
Korf, D.J.; Wouters, M.; Benschop, A.
The sale of cannabis to persons aged 18 or older is permitted in the Netherlands under certain conditions in commercial establishments called coffeeshops. The present Dutch government has proposed that access to coffeeshops be restricted to persons holding a cannabis ID, a mandatory membership card
García-Sánchez, Sara; Matalí, Josep Lluís; Martín-Fernández, María; Pardo, Marta; Lleras, Maria; Castellano-Tejedor, Carmina; Haro, Josep Maria
Cannabis is the illicit substance most widely used by adolescents. Certain personality traits such as impulsivity and sensation seeking, and the subjective effects experienced after substance use (e.g. euphoria or relaxation) have been identified as some of the main etiological factors of consumption. This study aims to categorize a sample of adolescent cannabis users based on their most dominant personality traits (internalizing and externalizing profile). Then, to make a comparison of both profiles considering a set of variables related to consumption, clinical severity and subjective effects experienced. From a cross-sectional design, 173 adolescents (104 men and 69 women) aged 13 to 18 asking for treatment for cannabis use disorder in an Addictive Behavior Unit (UCAD) from the hospital were recruited. For the assessment, an ad hoc protocol was employed to register consumption, the Millon Adolescent Clinical Inventory (MACI) and the Addiction Research Center Inventory (ARCI) 49-item short form were also administered. Factor analysis suggested a two-profile solution: Introverted, Inhibited, Doleful, Dramatizing (-), Egotistic (-), Self-demeaning and Borderline tendency scales composed the internalizing profile, and Submissive (-), Unruly, Forceful, Conforming (-) and Oppositional scales composed the externalizing profile. The comparative analysis showed that the internalizing profile has higher levels of clinical severity and more subjective effects reported than the externalizing profile. These results suggest the need to design specific intervention strategies for each profile.
Meier, Madeline H.; Caspi, Avshalom; Cerdá, Magdalena; Hancox, Robert J.; Harrington, HonaLee; Houts, Renate; Poulton, Richie; Ramrakha, Sandhya; Thomson, W. Murray; Moffitt, Terrie E.
Importance Following major policy changes in the United States, policy makers, clinicians, and the general public seek information about whether recreational cannabis use is associated with physical health problems later in life. Objective To test associations between cannabis use over twenty years and a variety of physical health indices at early midlife. Design A 38-year, prospective, longitudinal study of a representative birth cohort. Setting The Dunedin Multidisciplinary Health and Development Study of New Zealand. Participants The study included 1,037 male and female participants. Exposure We assessed frequency of cannabis use and also cannabis dependence at ages 18, 21, 26, 32, and 38 years. Main Outcomes and Measures We obtained laboratory measures of physical health (periodontal health, lung function, systemic inflammation, and metabolic health), as well as self-reported physical health, at ages 26 and 38. Results Cannabis use was associated with poorer periodontal health at age 38 and within-individual decline in periodontal health from age 26–38. For example, 55.61% of those with 15+ joint years had periodontal disease, compared with 13.53% of those who never used cannabis. Cannabis use was unrelated to other physical health problems, however. Unlike cannabis use, tobacco use was associated with worse lung function, systemic inflammation, and metabolic health at age 38, as well as within-individual decline in health from age 26 to 38. Conclusions and Relevance Cannabis use for up to 20 years is associated with periodontal disease but is not associated with other physical health problems in early midlife. PMID:27249330
de la Serna, Elena; Mayoral, María; Baeza, Inmaculada; Arango, Celso; Andrés, Patricia; Bombin, Igor; González, Cristina; Rapado, Marta; Robles, Olalla; Rodríguez-Sánchez, Jose Manuel; Zabala, Arantzazu; Castro-Fornieles, Josefina
To investigate the relationship between cognition and prior cannabis use in children and adolescents presenting a first episode of psychosis. A total of 107 patients with first episode of psychosis and 96 healthy controls, aged 9 to 17 years, were interviewed about their previous substance use and to assess their cognitive functions. Patients were assessed while not using cannabis by means of a comprehensive neuropsychological battery. They were divided into 2 groups depending on the history of prior cannabis use: cannabis users (CU) and cannabis nonusers (CNU). Significant differences were found in all areas evaluated between the 3 groups. Both CU and CNU patients obtained lower scores than controls on verbal learning and memory and working memory. Patients with prior cannabis use performed better on some tests of attention (Continuous performance test (CPT) number of correct responses, p = 0.002; CPT average reaction time, p < 0.001) and executive functions (Trail Making Test, part B (TMT-B) number of mistakes, p < 0.001; Wisconsin Card Sorting Test (WCST) number of categories completed, p < 0.001) than CNU patients. CU patients performed better than CNU subjects on some cognitive measures. This may indicate lower individual vulnerability for psychosis in CU patients in whom cannabis use can be a precipitating factor of psychotic episodes.
Meier, Madeline H; Caspi, Avshalom; Cerdá, Magdalena; Hancox, Robert J; Harrington, HonaLee; Houts, Renate; Poulton, Richie; Ramrakha, Sandhya; Thomson, W Murray; Moffitt, Terrie E
After major policy changes in the United States, policymakers, health care professionals, and the general public seek information about whether recreational cannabis use is associated with physical health problems later in life. To test associations between cannabis use over 20 years and a variety of physical health indexes at early midlife. Participants belonged to a representative birth cohort of 1037 individuals born in Dunedin, New Zealand, in 1972 and 1973 and followed to age 38 years, with 95% retention (the Dunedin Multidisciplinary Health and Development Study). We tested whether cannabis use from ages 18 to 38 years was associated with physical health at age 38, even after controlling for tobacco use, childhood health, and childhood socioeconomic status. We also tested whether cannabis use from ages 26 to 38 years was associated with within-individual health decline using the same measures of health at both ages. We assessed frequency of cannabis use and cannabis dependence at ages 18, 21, 26, 32, and 38 years. We obtained laboratory measures of physical health (periodontal health, lung function, systemic inflammation, and metabolic health), as well as self-reported physical health, at ages 26 and 38 years. The 1037 study participants were 51.6% male (n = 535). Of these, 484 had ever used tobacco daily and 675 had ever used cannabis. Cannabis use was associated with poorer periodontal health at age 38 years and within-individual decline in periodontal health from ages 26 to 38 years. For example, cannabis joint-years from ages 18 to 38 years was associated with poorer periodontal health at age 38 years, even after controlling for tobacco pack-years (β = 0.12; 95% CI, 0.05-0.18; P accounting for periodontal health at age 26 years and tobacco pack-years (β = 0.10; 95% CI, 0.05-0.16; P problems. Unlike cannabis use, tobacco use was associated with worse lung function, systemic inflammation, and metabolic health at age 38 years, as well as within
Bou-Matar Ché B
Full Text Available Abstract Background Cannabis (marijuana had been used for medicinal purposes for millennia. Cannabinoid agonists are now attracting growing interest and there is also evidence that botanical cannabis is being used as self-medication for stress and anxiety as well as adjunctive therapy by the seriously ill and by patients with terminal illnesses. California became the first state to authorize medicinal use of cannabis in 1996, and it was recently estimated that between 250,000 and 350,000 Californians may now possess the physician's recommendation required to use it medically. More limited medical use has also been approved in 12 additional states and new initiatives are being considered in others. Despite that evidence of increasing public acceptance of "medical" use, a definitional problem remains and all use for any purpose is still prohibited by federal law. Results California's 1996 initiative allowed cannabis to be recommended, not only for serious illnesses, but also "for any other illness for which marijuana provides relief," thus maximally broadening the range of allowable indications. In effect, the range of conditions now being treated with federally illegal cannabis, the modes in which it is being used, and the demographics of the population using it became potentially discoverable through the required screening of applicants. This report examines the demographic profiles and other selected characteristics of 4117 California marijuana users (62% from the Greater Bay Area who applied for medical recommendations between late 2001 and mid 2007. Conclusion This study yielded a somewhat unexpected profile of a hitherto hidden population of users of America's most popular illegal drug. It also raises questions about some of the basic assumptions held by both proponents and opponents of current policy.
Ruth Braidwood; Samantha Mansell; Jon Waldron; Peter G. Rendell; Sunjeev K. Kamboj; H. Valerie Curran
Research suggests that daily cannabis users have impaired memory for past events, but it is not clear whether they are also impaired in prospective memory (PM) for future events. The present study examined PM in daily cannabis users who were either dependent (n = 18) or non-dependent (n = 18), and compared them with non-using controls (n = 18). The effect of future event simulation (FES) on PM performance was also examined. Participants were matched across groups on age, gender, and highest l...
Treloar Padovano, Hayley; Miranda, Robert
The present study used youth's in vivo reports of subjective responses to cannabis while smoking in their natural environments to identify real-world mechanisms of topiramate treatment for cannabis misuse. Participants were 40 cannabis users (≥ twice weekly in past 30 days), ages 15-24 years (47.5% female), with at least one cannabis use episode during the final 3 weeks of a 6-week, randomized clinical trial. Youth reported subjective "high" while smoking, stimulation, sedation, stress, craving, and grams of marijuana used in the natural environment via wireless electronic devices. Bayesian multilevel structural equation modeling (MSEM) evaluated mediation via indirect effect tests. Significant within (daily) and between (person) variability and distinctive within and between effects supported the MSEM approach. Subjective high while smoking was significantly reduced for youth in the topiramate condition, relative to placebo, and the indirect effect of reduced subjective high on total grams of cannabis smoked that day was significant. Indirect effects through other subjective responses were not significant. The results of this initial study suggest that altering subjective responses to smoking, specifically subjective high, may be a key target for developing adjunctive pharmacotherapies for cannabis misuse. More generally, this work provides an example for applying ecological momentary assessment and analytic techniques to evaluate mechanisms of behavior change in longitudinal data.
De Sousa Fernandes Perna, E B; Theunissen, E L; Kuypers, K P C; Toennes, S W; Ramaekers, J G
Alcohol and cannabis use have been implicated in aggression. Alcohol consumption is known to facilitate aggression, whereas a causal link between cannabis and aggression has not been clearly demonstrated. This study investigated the acute effects of alcohol and cannabis on subjective aggression in alcohol and cannabis users, respectively, following aggression exposure. Drug-free controls served as a reference. It was hypothesized that aggression exposure would increase subjective aggression in alcohol users during alcohol intoxication, whereas it was expected to decrease subjective aggression in cannabis users during cannabis intoxication. Heavy alcohol (n = 20) and regular cannabis users (n = 21), and controls (n = 20) were included in a mixed factorial study. Alcohol and cannabis users received single doses of alcohol and placebo or cannabis and placebo, respectively. Subjective aggression was assessed before and after aggression exposure consisting of administrations of the point-subtraction aggression paradigm (PSAP) and the single category implicit association test (SC-IAT). Testosterone and cortisol levels in response to alcohol/cannabis treatment and aggression exposure were recorded as secondary outcome measures. Subjective aggression significantly increased following aggression exposure in all groups while being sober. Alcohol intoxication increased subjective aggression whereas cannabis decreased the subjective aggression following aggression exposure. Aggressive responses during the PSAP increased following alcohol and decreased following cannabis relative to placebo. Changes in aggressive feeling or response were not correlated to the neuroendocrine response to treatments. It is concluded that alcohol facilitates feelings of aggression whereas cannabis diminishes aggressive feelings in heavy alcohol and regular cannabis users, respectively.
Freeman, Tom P; Morgan, Celia J A; Hindocha, Chandni; Schafer, Gráinne; Das, Ravi K; Curran, H Valerie
(1) To determine whether measured concentrations of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) in individuals' own cannabis predict their estimates of drug potency and actual titration; and (2) to ascertain if these effects are influenced by frequency of use and cannabis type. Cross-sectional, naturalistic. Participants' own homes. A total of 247 cannabis users in the United Kingdom: 152 'recreational' (1-24 days/month) and 95 'daily' (≥25 days/month). Participants rated their own cannabis for its potency (1-10) and type ('resin', 'herbal', 'skunk') before smoking it in front of the researcher. The amount of cannabis (g) used in their joints was recorded and an additional sample was analysed for THC and CBD concentrations (%). THC concentrations were related negatively to the amount of cannabis used [unstandardized regression coefficient: b = -0.009, 95% confidence interval (CI) = -0.017, -0.002]. Potency estimates were predicted by increasing THC (b = 0.055, 95% CI = 0.020, 0.090) and decreasing CBD (b = -0.160, 95% CI = -0.284, -0.062), and both of these associations were mediated by cannabis type (THC: b = 0.018, 95% CI = 0.006, 0.037; CBD: b = -0.105, 95% CI = -0.198, -0.028). Potency estimates were more reflective of THC as frequency of use increased (b = 0.004, 95% CI = 0.001, 0.007) and were 7.3 times more so in daily (partial r = 0.381) than recreational users (r = 0.052). When using their own cannabis in a naturalistic setting, people titrate the amount they roll in joints according to concentrations of delta-9-tetrahydrocannabinol (THC) but not cannabidiol (CBD). Recreational users thus show poor understanding of cannabis potency. © 2014 Society for the Study of Addiction.
Janette L. Smith
Full Text Available Aims: Long-term heavy use of cannabis and alcohol are known to be associated with memory impairments. In this study, we used event-related potentials to examine verbal learning and memory processing in a commonly used behavioral task.Method: We conducted two studies: first, a small pilot study of adolescent males, comprising 13 Drug-Naive Controls (DNC, 12 heavy drinkers (HD and 8 cannabis users (CU. Second, a larger study of young adults, comprising 45 DNC (20 female, 39 HD (16 female, and 20 CU (9 female. In both studies, participants completed a modified verbal learning task (the Rey Auditory Verbal Learning Test, RAVLT while brain electrical activity was recorded. ERPs were calculated for words which were subsequently remembered vs. those which were not remembered, and for presentations of learnt words, previously seen words, and new words in a subsequent recognition test. Pre-planned principal components analyses (PCA were used to quantify the ERP components in these recall and recognition phases separately for each study.Results: Memory performance overall was slightly lower than published norms using the standardized RAVLT delivery, but was generally similar and showed the expected changes over trials. Few differences in performance were observed between groups; a notable exception was markedly poorer delayed recall in HD relative to DNC (Study 2. PCA identified components expected from prior research using other memory tasks. At encoding, there were no between-group differences in the usual P2 recall effect (larger for recalled than not-recalled words. However, alcohol-related differences were observed in a larger P540 (indexing recollection in HD than DNC, and cannabis-related differences were observed in a smaller N340 (indexing familiarity and a lack of previously seen > new words effect for P540 in Study 2.Conclusions: This study is the first examination of ERPs in the RAVLT in healthy control participants, as well as substance
Cousijn, J.; Goudriaan, A.E.; Ridderinkhof, K.R.; van den Brink, W.; Veltman, D.J.; Wiers, R.W.
A potentially powerful predictor for the course of drug (ab)use is the approach-bias, that is, the pre-reflective tendency to approach rather than avoid drug-related stimuli. Here we investigated the neural underpinnings of cannabis approach and avoidance tendencies. By elucidating the predictive
Cousijn, Janna; Goudriaan, Anna E.; Ridderinkhof, K. Richard; van den Brink, Wim; Veltman, Dick J.; Wiers, Reinout W.
A potentially powerful predictor for the course of drug (ab) use is the approach-bias, that is, the pre-reflective tendency to approach rather than avoid drug-related stimuli. Here we investigated the neural underpinnings of cannabis approach and avoidance tendencies. By elucidating the predictive
Benschop, A.; Liebregts, N.; van der Pol, P.; Schaap, R.; Buisman, R.; van Laar, M.; van den Brink, W.; de Graaf, R.; Korf, D.J.
The Marijuana Motives Measure (MMM) has so far been examined mainly in student populations, often with relatively limited involvement in cannabis use. This study evaluated the factor structure of the MMM in a demographically mixed sample of 600 young adult (18-30 years) frequent (≥3 days per week)
Benschop, Annemieke; Liebregts, Nienke; van der Pol, Peggy; Schaap, Rick; Buisman, Renate; van Laar, Margriet; van den Brink, Wim; de Graaf, Ron; Korf, Dirk J.
The Marijuana Motives Measure (MMM) has so far been examined mainly in student populations, often with relatively limited involvement in cannabis use. This study evaluated the factor structure of the MMM in a demographically mixed sample of 600 young adult (18-30 years) frequent (≥ 3 days per week)
Full Text Available Abstract Background One in three young people use cannabis in Canada. Cannabis use can be associated with a variety of health problems which occur primarily among intensive/frequent users. Availability and effectiveness of conventional treatment for cannabis use is limited. While Brief Interventions (BIs have been shown to result in short-term reductions of cannabis use risks or problems, few studies have assessed their longer-term effects. The present study examined 12-month follow-up outcomes for BIs in a cohort of young Canadian high-frequency cannabis users where select short-term effects (3 months had previously been assessed and demonstrated. Findings N = 134 frequent cannabis users were recruited from among university students in Toronto, randomized to either an oral or a written cannabis BI, or corresponding health controls, and assessed in-person at baseline, 3-months, and 12-months. N = 72 (54 % of the original sample were retained for follow-up analyses at 12-months where reductions in ‘deep inhalation/breathholding’ (Q = 13.1; p Conclusions The results confirm findings from select other studies indicating the potential for longer-term and sustained risk reduction effects of BIs for cannabis use. While further research is needed on the long-term effects of BIs, these may be a valuable – and efficient – intervention tool in a public health approach to high-risk cannabis use.
Palali, Ali; van Ours, Jan
We investigate the determinants of the support for cannabis legalization finding a causal effect of personal experience with cannabis use. Current and past cannabis users are more in favor of legalization. We relate this finding to self-interest and inside information about potential dangers of
Batalla, Albert; Bhattacharyya, Sagnik; Yücel, Murat; Fusar-Poli, Paolo; Crippa, Jose Alexandre; Nogué, Santiago; Torrens, Marta; Pujol, Jesús; Farré, Magí; Martin-Santos, Rocio
Background The growing concern about cannabis use, the most commonly used illicit drug worldwide, has led to a significant increase in the number of human studies using neuroimaging techniques to determine the effect of cannabis on brain structure and function. We conducted a systematic review to assess the evidence of the impact of chronic cannabis use on brain structure and function in adults and adolescents. Methods Papers published until August 2012 were included from EMBASE, Medline, PubMed and LILACS databases following a comprehensive search strategy and pre-determined set of criteria for article selection. Only neuroimaging studies involving chronic cannabis users with a matched control group were considered. Results One hundred and forty-two studies were identified, of which 43 met the established criteria. Eight studies were in adolescent population. Neuroimaging studies provide evidence of morphological brain alterations in both population groups, particularly in the medial temporal and frontal cortices, as well as the cerebellum. These effects may be related to the amount of cannabis exposure. Functional neuroimaging studies suggest different patterns of resting global and brain activity during the performance of several cognitive tasks both in adolescents and adults, which may indicate compensatory effects in response to chronic cannabis exposure. Limitations However, the results pointed out methodological limitations of the work conducted to date and considerable heterogeneity in the findings. Conclusion Chronic cannabis use may alter brain structure and function in adult and adolescent population. Further studies should consider the use of convergent methodology, prospective large samples involving adolescent to adulthood subjects, and data-sharing initiatives. PMID:23390554
Full Text Available The growing concern about cannabis use, the most commonly used illicit drug worldwide, has led to a significant increase in the number of human studies using neuroimaging techniques to determine the effect of cannabis on brain structure and function. We conducted a systematic review to assess the evidence of the impact of chronic cannabis use on brain structure and function in adults and adolescents.Papers published until August 2012 were included from EMBASE, Medline, PubMed and LILACS databases following a comprehensive search strategy and pre-determined set of criteria for article selection. Only neuroimaging studies involving chronic cannabis users with a matched control group were considered.One hundred and forty-two studies were identified, of which 43 met the established criteria. Eight studies were in adolescent population. Neuroimaging studies provide evidence of morphological brain alterations in both population groups, particularly in the medial temporal and frontal cortices, as well as the cerebellum. These effects may be related to the amount of cannabis exposure. Functional neuroimaging studies suggest different patterns of resting global and brain activity during the performance of several cognitive tasks both in adolescents and adults, which may indicate compensatory effects in response to chronic cannabis exposure.However, the results pointed out methodological limitations of the work conducted to date and considerable heterogeneity in the findings.Chronic cannabis use may alter brain structure and function in adult and adolescent population. Further studies should consider the use of convergent methodology, prospective large samples involving adolescent to adulthood subjects, and data-sharing initiatives.
Cohen, Nicole L.; Heinz, Adrienne J.; Ilgen, Mark; Bonn-Miller, Marcel O.
Objective: The purpose of this study was to examine whether individuals who used medical cannabis for chronic pain were at increased risk for cannabis use problems compared with individuals who used medical cannabis for other reasons (e.g., anxiety, insomnia, and muscle spasms). An additional aim was to determine whether individuals who used cannabis for chronic pain, as well as those who reported greater within-group pain levels, demonstrated a species preference (i.e., sativa, indica, hybrids) and the extent to which species preference was associated with cannabis use problems. Method: Participants were 163 medical cannabis users (77% male), recruited from a medical marijuana dispensary in California, who completed assessments of medical cannabis use motives, history, preferences (species type), and problems, as well as current pain level. Results: Individuals who used cannabis to manage chronic pain experienced fewer cannabis use problems than those who did not use it for pain; among those who used it for pain, the average pain level in the past week was not associated with cannabis use problems. Furthermore, individuals who used cannabis for chronic pain were more likely to use indica over sativa. Preference for indica was associated with fewer cannabis use problems than preference for hybrid species. Conclusions: Individuals who use cannabis to manage chronic pain may be at a lower risk for cannabis use problems, relative to individuals who use it for other indications, potentially as a function of their species preference. PMID:27172585
Cohen, Nicole L; Heinz, Adrienne J; Ilgen, Mark; Bonn-Miller, Marcel O
The purpose of this study was to examine whether individuals who used medical cannabis for chronic pain were at increased risk for cannabis use problems compared with individuals who used medical cannabis for other reasons (e.g., anxiety, insomnia, and muscle spasms). An additional aim was to determine whether individuals who used cannabis for chronic pain, as well as those who reported greater within-group pain levels, demonstrated a species preference (i.e., sativa, indica, hybrids) and the extent to which species preference was associated with cannabis use problems. Participants were 163 medical cannabis users (77% male), recruited from a medical marijuana dispensary in California, who completed assessments of medical cannabis use motives, history, preferences (species type), and problems, as well as current pain level. Individuals who used cannabis to manage chronic pain experienced fewer cannabis use problems than those who did not use it for pain; among those who used it for pain, the average pain level in the past week was not associated with cannabis use problems. Furthermore, individuals who used cannabis for chronic pain were more likely to use indica over sativa. Preference for indica was associated with fewer cannabis use problems than preference for hybrid species. Individuals who use cannabis to manage chronic pain may be at a lower risk for cannabis use problems, relative to individuals who use it for other indications, potentially as a function of their species preference.
Gilman, Jodi M; Kuster, John K; Lee, Sang; Lee, Myung Joo; Kim, Byoung Woo; Makris, Nikos; van der Kouwe, Andre; Blood, Anne J; Breiter, Hans C
Marijuana is the most commonly used illicit drug in the United States, but little is known about its effects on the human brain, particularly on reward/aversion regions implicated in addiction, such as the nucleus accumbens and amygdala. Animal studies show structural changes in brain regions such as the nucleus accumbens after exposure to Δ9-tetrahydrocannabinol, but less is known about cannabis use and brain morphometry in these regions in humans. We collected high-resolution MRI scans on young adult recreational marijuana users and nonusing controls and conducted three independent analyses of morphometry in these structures: (1) gray matter density using voxel-based morphometry, (2) volume (total brain and regional volumes), and (3) shape (surface morphometry). Gray matter density analyses revealed greater gray matter density in marijuana users than in control participants in the left nucleus accumbens extending to subcallosal cortex, hypothalamus, sublenticular extended amygdala, and left amygdala, even after controlling for age, sex, alcohol use, and cigarette smoking. Trend-level effects were observed for a volume increase in the left nucleus accumbens only. Significant shape differences were detected in the left nucleus accumbens and right amygdala. The left nucleus accumbens showed salient exposure-dependent alterations across all three measures and an altered multimodal relationship across measures in the marijuana group. These data suggest that marijuana exposure, even in young recreational users, is associated with exposure-dependent alterations of the neural matrix of core reward structures and is consistent with animal studies of changes in dendritic arborization.
Chaudhury, S; Sudarsanan, S; Salujha, S K; Srivastava, K
Cannabis abuse has been associated with psychiatric disorders. The pattern of cannabis use and incidence of cannabis dependence and cannabis psychosis among 471 consecutive patients admitted to a tertiary care psychiatric center was investigated. Cannabis use was reported by 67 (14.23%) patients of whom 42 (8.92%) were occasional users, 18 (3.82%) were classified as frequent users while 7 (1.49%) fulfilled criteria for cannabis dependence. 3 (0.64%) patients showed symptoms which were characteristic of cannabis psychosis. Among the 67 cannabis users, 56 (83.58%) had their first exposure to cannabis before entering service at 13-19 years of age. The remaining 14 (16.09%) began consuming cannabis 1-5 years after joining service. The reasons given for using cannabis were curiosity about its effects 32 (47.76%), peer pressure 17 (25.37%) or traditional use during festivals 18 (26.87%).
Hermann, Derik; Sartorius, Alexander; Welzel, Helga; Walter, Sigrid; Skopp, Gisela; Ende, Gabriele; Mann, Karl
Cannabinoids present neurotoxic and neuroprotective properties in in vitro studies, inconsistent alterations in human neuroimaging studies, neuropsychological deficits, and an increased risk for psychotic episodes. Proton magnetic resonance spectroscopy ((1)H-MRS), neuropsychological testing, and hair analysis for cannabinoids was performed in 13 male nontreatment-seeking recreational cannabis users and 13 male control subjects. A significantly diminished N-acetylaspartate/total creatine (NAA/tCr) ratio in the dorsolateral prefrontal cortex (DLPFC) was observed in cannabis users (p = .0003). The NAA/tCr in the putamen/globus pallidum region correlated significantly with cannabidiol (R(2) = .66, p = .004). Results of the Wisconsin Card Sorting test, Trail making Test, and D2 test for attention were influenced by cannabinoids. Chronic recreational cannabis use is associated with an indication of diminished neuronal and axonal integrity in the DLPFC in this study. As chronic cannabis use is a risk factor for psychosis, these results are interesting because diminished NAA/tCr ratios in the DLPFC and neuropsychological deficits were also reported in schizophrenia. The strong positive correlation of NAA/tCr and cannabidiol in the putamen/globus pallidum is in line with neuroprotective properties of cannabidiol, which were also observed in in vitro model studies of Parkinson's disease.
Ferraro, Laura; Russo, Manuela; O'Connor, Jennifer; Wiffen, Benjamin D R; Falcone, Maria Aurora; Sideli, Lucia; Gardner-Sood, Poonam; Stilo, Simona; Trotta, Antonella; Dazzan, Paola; Mondelli, Valeria; Taylor, Heather; Friedman, Bess; Sallis, Hannah; La Cascia, Caterina; La Barbera, Daniele; David, Anthony S; Reichenberg, Abraham; Murray, Robin M; Di Forti, Marta
A number of studies have reported that patients with psychosis who use cannabis have better cognitive performance than those who do not. This is surprising as cannabis can impair cognition in healthy subjects. An obvious question is whether the better current performance of psychotic patients who have used cannabis is a reflection of their having a higher premorbid IQ than those psychotic patients who haven't used cannabis. In a sample of patients at their first episode of psychosis, we tested the hypothesis that patients who smoked cannabis would have a higher premorbid IQ than patients who did not. 279 participants (119 patients and 160 healthy controls) were assessed in order to obtain current and premorbid IQ measures and detailed information on cannabis use. We examined the association between cannabis use and both premorbid and current IQ in patients and controls. Patients who had ever smoked cannabis had significantly higher current (pIQ (p=.004) compared to patients who had never used cannabis. This difference was not found among controls. These findings suggest that the better cognitive performance of patients with their first episode of psychosis who have used cannabis compared with those who haven't is due to the better premorbid IQ of the former. © 2013.
Vandrey, Ryan; Stitzer, Maxine L; Mintzer, Miriam Z; Huestis, Marilyn A; Murray, Jeannie A; Lee, Dayong
Prior studies have separately examined the effects of dronabinol (oral THC) on cannabis withdrawal, cognitive performance, and the acute effects of smoked cannabis. A single study examining these clinically relevant domains would benefit the continued evaluation of dronabinol as a potential medication for the treatment of cannabis use disorders. Thirteen daily cannabis smokers completed a within-subject crossover study and received 0, 30, 60 and 120mg dronabinol per day for 5 consecutive days. Vital signs and subjective ratings of cannabis withdrawal, craving and sleep were obtained daily; outcomes under active dose conditions were compared to those obtained under placebo dosing. On the 5th day of medication maintenance, participants completed a comprehensive cognitive performance battery and then smoked five puffs of cannabis for subjective effects evaluation. Each dronabinol maintenance period occurred in a counterbalanced order and was separated by 9 days of ad libitum cannabis use. Dronabinol dose-dependently attenuated cannabis withdrawal and resulted in few adverse side effects or decrements in cognitive performance. Surprisingly, dronabinol did not alter the subjective effects of smoked cannabis, but cannabis-induced increases in heart rate were attenuated by the 60 and 120mg doses. Dronabinol's ability to dose-dependently suppress cannabis withdrawal may be therapeutically beneficial to individuals trying to stop cannabis use. The absence of gross cognitive impairment or side effects in this study supports safety of doses up to 120mg/day. Continued evaluation of dronabinol in targeted clinical studies of cannabis treatment, using an expanded range of doses, is warranted. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
Moreno-Alcázar, Ana; Gonzalvo, Begoña; Canales-Rodríguez, Erick J; Blanco, Laura; Bachiller, Diana; Romaguera, Anna; Monté-Rubio, Gemma C; Roncero, Carlos; McKenna, Peter J; Pomarol-Clotet, Edith
Background: Structural imaging studies of cannabis users have found evidence of both cortical and subcortical volume reductions, especially in cannabinoid receptor-rich regions such as the hippocampus and amygdala. However, the findings have not been consistent. In the present study, we examined a sample of adult heavy cannabis users without other substance abuse to determine whether long-term use is associated with brain structural changes, especially in the subcortical regions. Method: We compared the gray matter volume of 14 long-term, heavy cannabis users with non-using controls. To provide robust findings, we conducted two separate studies using two different MRI techniques. Each study used the same sample of cannabis users and a different control group, respectively. Both control groups were independent of each other. First, whole-brain voxel-based morphometry (VBM) was used to compare the cannabis users against 28 matched controls (HC1 group). Second, a volumetric analysis of subcortical regions was performed to assess differences between the cannabis users and a sample of 100 matched controls (HC2 group) obtained from a local database of healthy volunteers. Results: The VBM study revealed that, compared to the control group HC1, the cannabis users did not show cortical differences nor smaller volume in any subcortical structure but showed a cluster ( p users showed significantly larger volumes in the putamen ( p = 0.001) and pallidum ( p = 0.0015). Subtle trends, only significant at the uncorrected level, were also found in the caudate ( p = 0.05) and nucleus accumbens ( p = 0.047). Conclusions: This study does not support previous findings of hippocampal and/or amygdala structural changes in long-term, heavy cannabis users. It does, however, provide evidence of basal ganglia volume increases.
Fogel, Jessica S; Kelly, Thomas H; Westgate, Philip M; Lile, Joshua A
Previous studies suggest that there are sex differences in endocannabinoid function and the response to exogenous cannabinoids, though data from clinical studies comparing acute cannabinoid effects in men and women under controlled laboratory conditions are limited. To further explore these potential differences, data from 30 cannabis users (N=18 M, 12 F) who completed previous Δ 9 -tetrahydrocannabinol (Δ 9 -THC) discrimination studies were combined for this retrospective analysis. In each study, subjects learned to discriminate between oral Δ 9 -THC and placebo and then received a range of Δ 9 -THC doses (0, 5, 15 and a "high" dose of either 25 or 30mg). Responses on a drug-discrimination task, subjective effects questionnaire, psychomotor performance tasks, and physiological measures were assessed. Δ 9 -THC dose-dependently increased drug-appropriate responding, ratings on "positive" Visual Analog Scale (VAS) items (e.g., good effects, like drug, take again), and items related to intoxication (e.g., high, stoned). Δ 9 -THC also dose-dependently impaired performance on psychomotor tasks and elevated heart rate. Sex differences on VAS items emerged as a function of dose. Women exhibited significantly greater subjective responses to oral drug administration than men at the 5mg Δ 9 -THC dose, whereas men were more sensitive to the subjective effects of the 15mg dose of Δ 9 -THC than women. These results demonstrate dose-dependent separation in the subjective response to oral Δ 9 -THC administration by sex, which might contribute to the differential development of problematic cannabis use. Copyright © 2015 Elsevier Inc. All rights reserved.
Tamm, Leanne; Epstein, Jeffery N; Lisdahl, Krista M; Molina, Brooke; Tapert, Susan; Hinshaw, Stephen P; Arnold, L Eugene; Velanova, Katerina; Abikoff, Howard; Swanson, James M
Attention-deficit/hyperactivity disorder (ADHD) and cannabis use are each associated with specific cognitive deficits. Few studies have investigated the neurocognitive profile of individuals with both an ADHD history and regular cannabis use. The greatest cognitive impairment is expected among ADHD Cannabis Users compared to those with ADHD-only, Cannabis use-only, or neither. Young adults (24.2 ± 1.2 years) with a childhood ADHD diagnosis who did (n=42) and did not (n=45) report past year ≥ monthly cannabis use were compared on neuropsychological measures to a local normative comparison group (LNCG) who did (n=20) and did not (n=21) report past year regular cannabis use. Age, gender, IQ, socioeconomic status, and past year alcohol and smoking were statistical covariates. The ADHD group performed worse than LNCG on verbal memory, processing speed, cognitive interference, decision-making, working memory, and response inhibition. No significant effects for cannabis use emerged. Interactions between ADHD and cannabis were non-significant. Exploratory analyses revealed that individuals who began using cannabis regularly before age 16 (n=27) may have poorer executive functioning (i.e., decision-making, working memory, and response inhibition), than users who began later (n=32); replication is warranted with a larger sample. A childhood diagnosis of ADHD, but not cannabis use in adulthood, was associated with executive dysfunction. Earlier initiation of cannabis use may be linked to poor cognitive outcomes and a significantly greater proportion of the ADHD group began using cannabis before age 16. Regular cannabis use starting after age 16 may not be sufficient to aggravate longstanding cognitive deficits characteristic of ADHD. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Bitter, Samantha M; Adler, Caleb M; Eliassen, James C; Weber, Wade A; Welge, Jeffrey A; Burciaga, Joaquin; Shear, Paula K; Strakowski, Stephen M; DelBello, Melissa P
To compare regional brain activation among adolescents with bipolar disorder and co-occurring cannabis use disorder. Cross-sectional study. Cincinnati, OH, USA. Adolescents with bipolar disorder (BP, n = 14), adolescents with cannabis use disorder (MJ, n = 13), adolescents with co-occurring cannabis use and bipolar disorders (BPMJ, n = 25) and healthy adolescents (HC, n = 15). Cannabis craving, substance use, Blood Oxygenation Level Dependent (BOLD) signal assessed by the Marijuana Craving Questionnaire (MCQ), Teen-Addiction Severity Index (T-ASI) and a cannabis cue-reactivity task during a functional magnetic resonance imaging (fMRI) session, respectively. The BP group exhibited significantly greater brain activation than the BPMJ group in the right amygdala (F = 4.14, P = 0.046), left nucleus accumbens (F = 3.8, P = 0.02), left thalamus (F = 3.8, P adolescents with comorbid cannabis use do not exhibit the same over-activation of the regions involved in emotional processing as seen in adolescents with bipolar disorder alone. The absence of these findings in patients with comorbid bipolar and cannabis use disorders suggests that these individuals may have a unique endophenotype of bipolar disorder or that cannabis use may alter brain activation uniquely in bipolar disorder patients who use cannabis. © 2014 Society for the Study of Addiction.
Fergusson, David M; Horwood, L John; Northstone, Kate
To document the prevalence of cannabis use in a large sample of British women studied during pregnancy, to determine the association between cannabis use and social and lifestyle factors and assess any independent effects on pregnancy outcome. Self-completed questionnaire on use of cannabis before and during pregnancy. Over 12,000 women expecting singletons at 18 to 20 weeks of gestation who were enrolled in the Avon Longitudinal Study of Pregnancy and Childhood. Any association with the use of cannabis before and during pregnancy with pregnancy outcome was examined, taking into account potentially confounding factors including maternal social background and other substance use during pregnancy. Late fetal and perinatal death, special care admission of the newborn infant, birthweight, birth length and head circumference. Five percent of mothers reported smoking cannabis before and/or during pregnancy; they were younger, of lower parity, better educated and more likely to use alcohol, cigarettes, coffee, tea and hard drugs. Cannabis use during pregnancy was unrelated to risk of perinatal death or need for special care, but, the babies of women who used cannabis at least once per week before and throughout pregnancy were 216 g lighter than those of non-users, had significantly shorter birth lengths and smaller head circumferences. After adjustment for confounding factors, the association between cannabis use and birthweight failed to be statistically significant (P = 0.056) and was clearly non-linear: the adjusted mean birthweights for babies of women using cannabis at least once per week before and throughout pregnancy were 90 g lighter than the offspring of other women. No significant adjusted effects were seen for birth length and head circumference. The results of this study suggest that the use of cannabis during pregnancy was not associated with increased risk of perinatal mortality or morbidity in this sample. However, frequent and regular use of cannabis
Ashlee A Moore
Full Text Available Depression is a highly heterogeneous condition, and identifying how symptoms present in various groups may greatly increase our understanding of its etiology. Importantly, Major Depressive Disorder is strongly linked with Substance Use Disorders, which may ameliorate or exacerbate specific depression symptoms. It is therefore quite plausible that depression may present with different symptom profiles depending on an individual's substance use status. Given these observations, it is important to examine the underlying construct of depression in groups of substance users compared to non-users. In this study we use a non-clinical sample to examine the measurement structure of the Beck Depression Inventory (BDI-II in non-users and frequent-users of various substances. Specifically, measurement invariance was examined across those who do vs. do not use alcohol, nicotine, and cannabis. Results indicate strict factorial invariance across non-users and frequent-users of alcohol and cannabis, and metric invariance across non-users and frequent-users of nicotine. This implies that the factor structure of the BDI-II is similar across all substance use groups.
Moore, Ashlee A; Neale, Michael C; Silberg, Judy L; Verhulst, Brad
Depression is a highly heterogeneous condition, and identifying how symptoms present in various groups may greatly increase our understanding of its etiology. Importantly, Major Depressive Disorder is strongly linked with Substance Use Disorders, which may ameliorate or exacerbate specific depression symptoms. It is therefore quite plausible that depression may present with different symptom profiles depending on an individual's substance use status. Given these observations, it is important to examine the underlying construct of depression in groups of substance users compared to non-users. In this study we use a non-clinical sample to examine the measurement structure of the Beck Depression Inventory (BDI-II) in non-users and frequent-users of various substances. Specifically, measurement invariance was examined across those who do vs. do not use alcohol, nicotine, and cannabis. Results indicate strict factorial invariance across non-users and frequent-users of alcohol and cannabis, and metric invariance across non-users and frequent-users of nicotine. This implies that the factor structure of the BDI-II is similar across all substance use groups.
Full Text Available Abstract Background Cannabis is the most commonly used illegal drug and its therapeutic aspects have a growing interest. Short-term psychotic reactions have been described but not clearly with synthetic oral THC, especially in occasional users. Case presentations We report two cases of healthy subjects who were occasional but regular cannabis users without psychiatric history who developed transient psychotic symptoms (depersonalization, paranoid feelings and derealisation following oral administration of cannabis. In contrast to most other case reports where circumstances and blood concentrations are unknown, the two cases reported here happened under experimental conditions with all subjects negative for cannabis, opiates, amphetamines, cocaine, benzodiazepines and alcohol, and therefore the ingested dose, the time-events of effects on behavior and performance as well as the cannabinoid blood levels were documented. Conclusion While the oral route of administration achieves only limited blood concentrations, significant psychotic reactions may occur.
Hall, Wayne; Lynskey, Michael
Since 2012 four US states have legalized the retail sale of cannabis for recreational use by adults, and more are likely to follow. This report aimed to (1) briefly describe the regulatory regimes so far implemented; (2) outline their plausible effects on cannabis use and cannabis-related harm; and (3) suggest what research is needed to evaluate the public health impact of these policy changes. We reviewed the drug policy literature to identify: (1) plausible effects of legalizing adult recreational use on cannabis price and availability; (2) factors that may increase or limit these effects; (3) pointers from studies of the effects of legalizing medical cannabis use; and (4) indicators of cannabis use and cannabis-related harm that can be monitored to assess the effects of these policy changes. Legalization of recreational use will probably increase use in the long term, but the magnitude and timing of any increase is uncertain. It will be critical to monitor: cannabis use in household and high school surveys; cannabis sales; the number of cannabis plants legally produced; and the tetrahydrocannabinol (THC) content of cannabis. Indicators of cannabis-related harms that should be monitored include: car crash fatalities and injuries; emergency department presentations; presentations to addiction treatment services; and the prevalence of regular cannabis use among young people in mental health services and the criminal justice system. Plausible effects of legalizing recreational cannabis use in the United States include substantially reducing the price of cannabis and increasing heavy use and some types of cannabis-related harm among existing users. In the longer term it may also increase the number of new users. © 2016 Society for the Study of Addiction.
Buckner, Julia D; Zvolensky, Michael J; Ecker, Anthony H; Jeffries, Emily R
Social anxiety disorder appears to be a risk factor for cannabis-related problems. Although it is presumed that increases in cannabis craving during elevated social anxiety reflect an intent to cope with greater negative affectivity, it is unclear whether increases in physiological arousal during social stress are related to cannabis craving, especially among those with social anxiety disorder. Similarly, no studies have assessed motivational reasons for cannabis use during elevated social st...
Odell, Morris S; Frei, Matthew Y; Gerostamoulos, Dimitri; Chu, Mark; Lubman, Dan I
An understanding of tetrahydrocannabinol (THC) kinetics and residual levels after cannabis use is essential in interpreting toxicology tests in body fluids from live subjects, particularly when used in forensic settings for drug abuse, traffic and interpersonal violence cases. However the current literature is largely based on laboratory studies using controlled cannabis dosages in experienced users, with limited research investigating the kinetics of residual THC concentrations in regular high dose cannabis users. Twenty-one dependent cannabis users were recruited at admission to two residential detoxification units in Melbourne, Australia. After being provided with information about, and consenting to, the study, subjects volunteered to provide once-daily blood, urine and oral fluid (saliva) samples for seven consecutive days following admission, involving cessation and abstinence from all cannabis use. Blood and oral fluid specimens were analysed for THC and urine specimens for the metabolite THC-COOH. In some subjects THC was detectable in blood for at least 7 days and oral fluid specimens were positive for THC up to 78 h after admission to the unit. Urinary THC-COOH concentrations exceeded 1000 ng/mL for some subjects 129 h after last use. The presented blood THC levels are higher and persist longer in some individuals than previously described, our understanding and interpretation of THC levels in long term heavy cannabis users may need to be reconsidered. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Burdzovic Andreas, Jasmina; Pape, Hilde; Bretteville-Jensen, Anne Line
Adolescents who refuse direct cannabis offers and remain non-users represent a potentially very informative, yet surprisingly understudied group. We examined a range of risk and protective factors putatively associated with this poorly understood "cannabis-resilient" profile. Paper-and-pencil questionnaires assessing substance use, peer and family relations, and behavioral and personality characteristics were completed by 19,303 middle- and high-school students from 82 schools in Norway (response rate 84%) The lifetime prevalence of cannabis use was 7.6%. Another 10.4% reported no use of the drug despite having received recent cannabis offers. Results from the multinomial logistic regression revealed a set of characteristics differentiating adolescents who resisted such offers from those who: (a) neither received the offers nor used, and, more importantly, (b) used the drug. Specifically, parent-child relationship quality, negative drug-related beliefs, absence of close relationships with cannabis-users, low delinquency, no regular tobacco use, and infrequent alcohol intoxication were all associated with increased odds of being in the cannabis-resilient vs. cannabis-user group. This pattern of results was comparable across middle- and high-school cohorts, but the parent-child relationship quality and delinquency were significantly associated with cannabis-resilient vs. cannabis-use outcome only among younger and older adolescents, respectively. Among other low-risk characteristics, better relationships with parents and beliefs that drug use is problematic were associated with adolescents' refusals to accept cannabis offers. These results may have implications for novel preventive strategies targeting cannabis-exposed adolescents. Copyright © 2016. Published by Elsevier Ireland Ltd.
Tamm, Leanne; Epstein, Jeffery N.; Lisdahl, Krista M.; Tapert, Susan; Hinshaw, Stephen P.; Arnold, L. Eugene; Velanova, Katerina; Abikoff, Howard; Swanson, James M.
BackgroundAttention-deficit/hyperactivity disorder (ADHD) and cannabis use are each associated with specific cognitive deficits. Few studies have investigated the neurocognitive profile of individuals with both an ADHD history and regular cannabis use. The greatest cognitive impairment is expected among ADHD Cannabis Users compared to those with ADHD-only, Cannabis use-only, or neither.MethodsYoung adults (24.2±1.2 years) with a childhood ADHD diagnosis who did (n=42) and did not (n=45) repor...
Womack, Sean R.; Shaw, Daniel S.; Weaver, Chelsea M.; Forbes, Erika E.
Objective: Previous studies have established a relationship between cannabis use and affective problems among adolescents and young adults; however, the direction of these associations remains a topic of debate. The present study sought to examine bidirectional associations between cannabis use and depressive symptoms, specifically testing the validity of two competing hypotheses: the cannabis effect hypothesis, which suggests that cannabis use contributes to the onset of later depressive symptoms; and the self-medication hypothesis, which posits that individuals increase their use of a substance to alleviate distressing psychological symptoms. Method: Participants in this study were 264 low-socioeconomic-status males assessed at ages 17, 20, and 22. Cross-lag panel models were fit to test bidirectional associations between cannabis use frequency and depressive symptoms across the transition from adolescence to early adulthood. In addition, analyses were conducted within two high-risk subsamples to examine whether associations between cannabis use frequency (ranging from never used to daily use) and depressive symptoms differed among regular cannabis users (used cannabis more than once per week) or subjects reporting at least mild levels of depressive symptoms. Results: Cannabis use and depressive symptoms were concurrently correlated. Cannabis use predicted increases in later depressive symptoms, but only among the mild-depression subsample. Depressive symptoms predicted only slight increases in later cannabis use, among the subsample of regular cannabis users. Conclusions: Temporal patterns of cannabis use and depressive symptoms provide evidence for the cannabis effect but limited evidence for the self-medication hypothesis. Adolescents higher in depressive symptoms may be vulnerable to the adverse psychological effects of using cannabis. Results are discussed in terms of implications for basic research, prevention, and intervention. PMID:26997187
Womack, Sean R; Shaw, Daniel S; Weaver, Chelsea M; Forbes, Erika E
Previous studies have established a relationship between cannabis use and affective problems among adolescents and young adults; however, the direction of these associations remains a topic of debate. The present study sought to examine bidirectional associations between cannabis use and depressive symptoms, specifically testing the validity of two competing hypotheses: the cannabis effect hypothesis, which suggests that cannabis use contributes to the onset of later depressive symptoms; and the self-medication hypothesis, which posits that individuals increase their use of a substance to alleviate distressing psychological symptoms. Participants in this study were 264 low-socioeconomic-status males assessed at ages 17, 20, and 22. Cross-lag panel models were fit to test bidirectional associations between cannabis use frequency and depressive symptoms across the transition from adolescence to early adulthood. In addition, analyses were conducted within two high-risk subsamples to examine whether associations between cannabis use frequency (ranging from never used to daily use) and depressive symptoms differed among regular cannabis users (used cannabis more than once per week) or subjects reporting at least mild levels of depressive symptoms. Cannabis use and depressive symptoms were concurrently correlated. Cannabis use predicted increases in later depressive symptoms, but only among the mild-depression subsample. Depressive symptoms predicted only slight increases in later cannabis use, among the subsample of regular cannabis users. Temporal patterns of cannabis use and depressive symptoms provide evidence for the cannabis effect but limited evidence for the self-medication hypothesis. Adolescents higher in depressive symptoms may be vulnerable to the adverse psychological effects of using cannabis. Results are discussed in terms of implications for basic research, prevention, and intervention.
Full Text Available Background: Structural imaging studies of cannabis users have found evidence of both cortical and subcortical volume reductions, especially in cannabinoid receptor-rich regions such as the hippocampus and amygdala. However, the findings have not been consistent. In the present study, we examined a sample of adult heavy cannabis users without other substance abuse to determine whether long-term use is associated with brain structural changes, especially in the subcortical regions.Method: We compared the gray matter volume of 14 long-term, heavy cannabis users with non-using controls. To provide robust findings, we conducted two separate studies using two different MRI techniques. Each study used the same sample of cannabis users and a different control group, respectively. Both control groups were independent of each other. First, whole-brain voxel-based morphometry (VBM was used to compare the cannabis users against 28 matched controls (HC1 group. Second, a volumetric analysis of subcortical regions was performed to assess differences between the cannabis users and a sample of 100 matched controls (HC2 group obtained from a local database of healthy volunteers.Results: The VBM study revealed that, compared to the control group HC1, the cannabis users did not show cortical differences nor smaller volume in any subcortical structure but showed a cluster (p < 0.001 of larger GM volume in the basal ganglia, involving the caudate, putamen, pallidum, and nucleus accumbens, bilaterally. The subcortical volumetric analysis revealed that, compared to the control group HC2, the cannabis users showed significantly larger volumes in the putamen (p = 0.001 and pallidum (p = 0.0015. Subtle trends, only significant at the uncorrected level, were also found in the caudate (p = 0.05 and nucleus accumbens (p = 0.047.Conclusions: This study does not support previous findings of hippocampal and/or amygdala structural changes in long-term, heavy cannabis users. It
Full Text Available Abstract Background The New South Wales State Government recently proposed a trial of the medical use of cannabis. Australians who currently use cannabis medicinally do so illegally and without assurances of quality control. Given the dearth of local information on this issue, this study explored the experiences of medical cannabis users. Methods Australian adults who had used cannabis for medical purposes were recruited using media stories. A total of 147 respondents were screened by phone and anonymous questionnaires were mailed, to be returned by postage paid envelope. Results Data were available for 128 participants. Long term and regular medical cannabis use was frequently reported for multiple medical conditions including chronic pain (57%, depression (56%, arthritis (35%, persistent nausea (27% and weight loss (26%. Cannabis was perceived to provide "great relief" overall (86%, and substantial relief of specific symptoms such as pain, nausea and insomnia. It was also typically perceived as superior to other medications in terms of undesirable effects, and the extent of relief provided. However, nearly one half (41% experienced conditions or symptoms that were not helped by its use. The most prevalent concerns related to its illegality. Participants reported strong support for their use from clinicians and family. There was almost universal interest (89% in participating in a clinical trial of medical cannabis, and strong support (79% for investigating alternative delivery methods. Conclusion Australian medical cannabis users are risking legal ramifications, but consistent with users elsewhere, claim moderate to substantial benefits from its use in the management of their medical condition. In addition to strong public support, medical cannabis users show strong interest in clinical cannabis research, including the investigation of alternative delivery methods.
Darke, Shane; Kaye, Sharlene; Torok, Michelle
To determine age-related patterns of drug use initiation, drug sequencing and treatment entry among regular psychostimulant users. Cross-sectional study of 269 regular psychostimulant users, administered a structured interview examining onset of use for major licit and illicit drugs. The mean age at first intoxication was not associated with age or gender. In contrast, younger age was associated with earlier ages of onset for all of the illicit drug classes. Each additional year of age was associated with a 4 month increase in onset age for methamphetamine, and 3 months for heroin. By the age of 17, those born prior to 1961 had, on average, used only tobacco and alcohol, whereas those born between 1986 and 1990 had used nine different drug classes. The period between initial use and the transition to regular use, however, was stable. Age was also negatively correlated with both age at initial injection and regular injecting. Onset sequences, however, remained stable. Consistent with the age-related patterns of drug use, each additional year of age associated with a 0.47 year increase in the age at first treatment. While the age at first intoxication appeared stable, the trajectory through illicit drug use was substantially truncated. The data indicate that, at least among those who progress to regular illicit drug use, younger users are likely to be exposed to far broader polydrug use in their teens than has previously been the case. © 2012 Australasian Professional Society on Alcohol and other Drugs.
Heitmann, Janika; van Hemel-Ruiter, Madelon E; Vermeulen, Karin M; Ostafin, Brian D; MacLeod, Colin; Wiers, Reinout W; DeFuentes-Merillas, Laura; Fledderus, Martine; Markus, Wiebren; de Jong, Peter J
The automatic tendency to attend to and focus on substance-related cues in the environment (attentional bias), has been found to contribute to the persistence of addiction. Attentional bias modification (ABM) interventions might, therefore, contribute to treatment outcome and the reduction of relapse rates. Based on some promising research findings, we designed a study to test the clinical relevance of ABM as an add-on component of regular intervention for alcohol and cannabis patients. The current protocol describes a study which will investigate the effectiveness and cost-effectiveness of a newly developed home-delivered, multi-session, internet-based ABM (iABM) intervention as an add-on to treatment as usual (TAU). TAU consists of cognitive behavioural therapy-based treatment according to the Dutch guidelines for the treatment of addiction. Participants (N = 213) will be outpatients from specialized addiction care institutions diagnosed with alcohol or cannabis dependency who will be randomly assigned to one of three conditions: TAU + iABM; TAU + placebo condition; TAU-only. Primary outcome measures are substance use, craving, and rates of relapse. Changes in attentional bias will be measured to investigate whether changes in primary outcome measures can be attributed to the modification of attentional bias. Indices of cost-effectiveness and secondary physical and psychological complaints (depression, anxiety, and stress) are assessed as secondary outcome measures. This randomized control trial will be the first to investigate whether a home-delivered, multi-session iABM intervention is (cost-) effective in reducing relapse rates in alcohol and cannabis dependency as an add-on to TAU, compared with an active and a waiting list control group. If proven effective, this ABM intervention could be easily implemented as a home-delivered component of current TAU. Netherlands Trial Register, NTR5497 , registered on 18th September 2015.
Hall, Wayne; Degenhardt, Louisa
For over two decades, cannabis, commonly known as marijuana, has been the most widely used illicit drug by young people in high-income countries, and has recently become popular on a global scale. Epidemiological research during the past 10 years suggests that regular use of cannabis during adolescence and into adulthood can have adverse effects. Epidemiological, clinical, and laboratory studies have established an association between cannabis use and adverse outcomes. We focus on adverse health effects of greatest potential public health interest-that is, those that are most likely to occur and to affect a large number of cannabis users. The most probable adverse effects include a dependence syndrome, increased risk of motor vehicle crashes, impaired respiratory function, cardiovascular disease, and adverse effects of regular use on adolescent psychosocial development and mental health.
Ward, Nicholas J; Schell, William; Kelley-Baker, Tara; Otto, Jay; Finley, Kari
This study explored a theoretical model to assess the influence of culture on willingness and intention to drive under the influence of cannabis (DUIC). This model is expected to guide the design of strategies to change future DUIC behavior in road users. This study used a survey methodology to obtain a nationally representative sample (n = 941) from the AmeriSpeak Panel. Survey items were designed to measure aspects of a proposed definition of traffic safety culture and a predictive model of its relationship to DUIC. Although the percentage of reported past DUIC behaviors was relatively low (8.5%), this behavior is still a significant public health issue-especially for younger drivers (18-29 years), who reported more DUIC than expected. Findings suggest that specific cultural components (attitudes, norms) reliably predict past DUIC behavior, general DUIC willingness, and future DUIC intention. Most DUIC behavior appears to be deliberate, related significantly to willingness and intention. Intention and willingness both appear to fully moderate the relationship between traffic safety culture and DUIC behavior. This study explored a theoretical model to understand road user behavior involving drug (cannabis)-impaired driving as a significant risk factor for traffic safety. By understanding the cultural factors that increase DUIC behavior, we can create strategies to transform this culture and sustain safer road user behavior.
Aims: To investigate the links between the visibility of cannabis use in school (measured by teachers' reports of students being under the influence of cannabis on school premises), the proportion of cannabis users in the class, perceived availability of cannabis, as well as adolescent cannabis use. Methods: A multilevel regression model was…
Aims - To investigate the links between the visibility of cannabis use in school (measured by teachers’ reports of students being under the influence of cannabis on school premises), the proportion of cannabis users in the class, perceived availability of cannabis, as well as adolescent cannabis
Galván, Gonzalo; Sánchez-Carballo, Álvaro; Gómez-Morales, Ileana; Humánez-Julio, Oscar; Guerrero-Martelo, Manuel; Vásquez De la Hoz, Francisco
Descriptive and comparative study of cross-sectional that had as objective to evaluate and compare the beliefs about cannabis, its use and potential consequences between two groups of Colombian university students, matched by gender and age. The frst group consisted of ordinary consumers of cannabis (n=35) the second group consisted of students that have never tried cannabis (n=35). The results showed that the group of consumers presents a moderate risk of abuse and only the 20% fulflled dependence criteria. Furthermore, the non-consumers group was mostly agree about that the marijuana use: damages the memory, deteriorates the cognitive functions, creates dependency, can affect the neurons and mental health. Also, it can lead to legal problems, it is a harmful drug for the health, it affects the academic performance, it creates problems with the family, friends, couple and the like, it reduces the driving ability, and, that the marijuana that is sold in the street is always pure. The consumer group, instead, agreed that smoking tobacco affects the lungs more than smoking marijuana. Marijuana has a positive in?uence on the brain, it increases the creativity, and it is less damaging than alcohol and tobacco. Smart people smoke marijuana and it has medicinal effects. In conclusion, according to the kind of beliefs that they have about this drug, the cannabis consumers would have a decreased perception of risk in relation to the potential risk that the consumption brings from two points of view: a. They minimize the real risks of consuming and, b. They attribute some benefts and virtues to the cannabis. The kind of beliefs that the consumer have are maybe in?uenced, at least, in part, for experiences of family and other consumers and, furthermore, the reinforcement of the same consume.
Urban, T; Hureaux, J
Cannabis use increased sharply from 2010 to 2014 in France. Cannabis is often consumed with tobacco, although the use of marijuana is developing. Tobacco and cannabis smoke have many common characteristics in terms of irritants, carcinogens and carbon monoxide. They also differentiate by their dependence mechanisms, with nicotine and its receptors for tobacco and tetra-hydro-cannabinol (THC) and its specific receptors for cannabis. Chronic inhalation (700,000 daily users in France) over a long period most likely increases the relative risk of bronchial cancer. But long-term cohort studies targeting this group of strong cannabis users, especially over time, are lacking. Inhalation of cannabis smoke, despite an acute bronchodilator effect, is associated with the risk of chronic bronchitis in the case of regular use. However, the risk of developing COPD in the exclusive marijuana smoker group with no associated tobacco is not yet clear, with studies yielding discordant results. There is also a lack of long-term follow-up studies of respiratory investigations in large cannabis users. Finally, cannabis smoke contains various cannabinoids, for example cannabidiol which also have anti-inflammatory and antifibrotic properties, with the unconfirmed hypothesis that these properties can partially modulate the deleterious action of cannabis smoke. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
Baldus, Christiane; Miranda, Alejandra; Weymann, Nina; Reis, Olaf; Moré, Kerstin; Thomasius, Rainer
Current research shows that overall numbers for cannabis use among adolescents and young adults dropped in recent years. However, this trend is much less pronounced in continuous cannabis use. With regard to the heightened risk for detrimental health- and development-related outcomes, adolescents and young adults with continuous cannabis use need special attention. The health services structure for adolescents and young adults with substance related problems in Germany, is multifaceted, because different communal, medical and judicial agencies are involved. This results in a rather decentralized organizational structure of the help system. This and further system-inherent characteristics make the threshold for young cannabis users rather high. Because of this, there is a need to establish evidence-based low-threshold help options for young cannabis users, which can be easily disseminated. Therefore, a training programme for young cannabis users (age 14-21) was developed in the "CAN Stop" project. Within the project, we seek to implement and evaluate the training programme within different institutions of the help system. The evaluation is sensitive to the different help systems and their specific prerequisites. Moreover, within this study, we also test the practicability of a training provision through laypersons. The CAN Stop study is a four-armed randomized wait-list controlled trial. The four arms are needed for the different help system settings, in which the CAN Stop training programme is evaluated: (a) the drug addiction aid and youth welfare system, (b) the out-patient medical system, (c) the in-patient medical system and (d) prisons for juvenile offenders. Data are collected at three points, before and after the training or a treatment as usual, and six months after the end of either intervention. The CAN Stop study is expected to provide an evidence-based programme for young cannabis users seeking to reduce or quit their cannabis use. Moreover, we seek to
Full Text Available Abstract Background Current research shows that overall numbers for cannabis use among adolescents and young adults dropped in recent years. However, this trend is much less pronounced in continuous cannabis use. With regard to the heightened risk for detrimental health- and development-related outcomes, adolescents and young adults with continuous cannabis use need special attention. The health services structure for adolescents and young adults with substance related problems in Germany, is multifaceted, because different communal, medical and judicial agencies are involved. This results in a rather decentralized organizational structure of the help system. This and further system-inherent characteristics make the threshold for young cannabis users rather high. Because of this, there is a need to establish evidence-based low-threshold help options for young cannabis users, which can be easily disseminated. Therefore, a training programme for young cannabis users (age 14-21 was developed in the "CAN Stop" project. Within the project, we seek to implement and evaluate the training programme within different institutions of the help system. The evaluation is sensitive to the different help systems and their specific prerequisites. Moreover, within this study, we also test the practicability of a training provision through laypersons. Methods/Design The CAN Stop study is a four-armed randomized wait-list controlled trial. The four arms are needed for the different help system settings, in which the CAN Stop training programme is evaluated: (a the drug addiction aid and youth welfare system, (b the out-patient medical system, (c the in-patient medical system and (d prisons for juvenile offenders. Data are collected at three points, before and after the training or a treatment as usual, and six months after the end of either intervention. Discussion The CAN Stop study is expected to provide an evidence-based programme for young cannabis users
Nika, Melisa; Blachley, Taylor S.; Edwards, Paul; Lee, Paul P.; Stein, Joshua D.
Importance According to evidence-based, expert recommendations, long-term users of chloroquine (CQ) or hydroxychloroquine (HCQ) should undergo regular visits to eye-care providers and diagnostic testing to check for maculopathy. Objective To determine whether patients with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) taking CQ or HCQ are regularly visiting eye-care providers and being screened for maculopathy. Setting, Design and Participants Patients with RA or SLE who were continuously enrolled in a particular managed-care network for ≥5 years during 2001-2011 were studied. Patients' amount of CQ/HCQ use in the 5 years since initial RA/SLE diagnosis was calculated, along with their number of eye-care visits and diagnostic tests for maculopathy. Those at high risk for maculopathy were identified. Visits to eye providers and diagnostic testing for maculopathy were assessed for each enrollee over the study period. Logistic regression was performed to assess potential factors associated with regular eye-care-provider visits (≥3 in 5 years) among CQ/HCQ users, including those at greatest risk for maculopathy. Main Outcome Measures Among CQ/HCQ users and those at high risk for toxic maculopathy, the proportions with regular eye-care visits and diagnostic testing, and the likelihood of regular eye-care visits (odds ratios [ORs] with 95% confidence intervals [CI]). Results Among 18,051 beneficiaries with RA or SLE, 6,339 (35.1%) had ≥1 record of HCQ/CQ use and 1,409 (7.8%) used HCQ/CQ for ≥4 years. Among those at high risk for maculopathy, 27.9% lacked regular eye-provider visits, 6.1% had no visits to eye providers, and 34.5% had no diagnostic testing for maculopathy during the 5-year period. Among high-risk patients, each additional month of HCQ/CQ use was associated with a 2.0%-increased likelihood of regular eye care (adjusted OR=1.02, CI=1.01-1.03). High-risk patients whose SLE/RA were managed by rheumatologists had a 77%-increased
Nika, Melisa; Blachley, Taylor S; Edwards, Paul; Lee, Paul P; Stein, Joshua D
According to evidence-based, expert recommendations, long-term users of chloroquine or hydroxychloroquine sulfate should undergo regular visits to eye care providers and diagnostic testing to check for maculopathy. To determine whether patients with rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE) taking chloroquine or hydroxychloroquine are regularly visiting eye care providers and being screened for maculopathy. Patients with RA or SLE who were continuously enrolled in a particular managed care network for at least 5 years between January 1, 2001, and December 31, 2011, were studied. Patients' amount of chloroquine or hydroxychloroquine use in the 5 years since the initial RA or SLE diagnosis was calculated, along with their number of eye care visits and diagnostic tests for maculopathy. Those at high risk for maculopathy were identified. Logistic regression was performed to assess potential factors associated with regular eye care visits (annual visits in ≥3 of 5 years) among chloroquine or hydroxychloroquine users, including those at highest risk for maculopathy. Among chloroquine or hydroxychloroquine users and those at high risk for toxic maculopathy, the proportions with regular eye care visits and diagnostic testing, as well as the likelihood of regular eye care visits. Among 18 051 beneficiaries with RA or SLE, 6339 (35.1%) had at least 1 record of chloroquine or hydroxychloroquine use, and 1409 (7.8%) had used chloroquine or hydroxychloroquine for at least 4 years. Among those at high risk for maculopathy, 27.9% lacked regular eye care visits, 6.1% had no visits to eye care providers, and 34.5% had no diagnostic testing for maculopathy during the 5-year period. Among high-risk patients, each additional month of chloroquine or hydroxychloroquine use was associated with a 2.0% increased likelihood of regular eye care (adjusted odds ratio, 1.02; 95% CI, 1.01-1.03). High-risk patients whose SLE or RA was managed by rheumatologists had a 77
Hirst, Rayna B; Young, Kaitlyn R; Sodos, Louise M; Wickham, Robert E; Earleywine, Mitch
While many studies suggest that regular cannabis use leads to deficits in cognitive functioning, particularly in memory, few have measured effort put forth during testing, and none have examined this as a potential mediator. Both age of onset of regular cannabis use and frequency of use have been linked to increased risk of memory deficits. The present study sought to determine whether effort mediated the relationship between frequency or age of onset of cannabis use and learning and memory performance. Sixty-two participants (74% male, mean age = 19.25 years) who met criteria for chronic cannabis use (four or more days per week for at least 12 months) completed a neuropsychological battery including the California Verbal Learning Test-II (CVLT-II) and the Rey Complex Figure (RCF) as measures of learning and memory, and the Word Memory Test (WMT) as a measure of effort put forth during neuropsychological assessment. Participants who more frequently used cannabis exhibited poorer effort (as measured by WMT performance; p cannabis use and CVLT-II Learning (Sum of Trials 1-5), CVLT-II Delayed Recall, and RCF Delayed Recall, but not RCF Immediate Recall. Age of onset of cannabis use was not significantly related to effort. Findings indicate that effort mediates the relationship between frequency of cannabis use and performance on learning and memory measures, suggesting that effort performance should be measured and controlled for in future studies assessing cognition in frequent cannabis users.
Mathai, David S; Holst, Manuela; Rodgman, Christopher; Haile, Colin N; Keller, Jake; Hussain, Mariyah Z; Kosten, Thomas R; Newton, Thomas F; Verrico, Christopher D
The cannabinoid-1 receptor (CB1R) agonist Δ9-tetrahydrocannabinol (THC), the main psychoactive constituent of cannabis, adversely effects working memory performance in humans. The α2A-adrenoceptor (AR) agonist guanfacine improves working memory performance in humans. The authors aimed to determine the effects of short-term (6 days) treatment with guanfacine on adverse cognitive effects produced by THC. Employing a double-blind, placebo-controlled crossover design, the cognitive, subjective, and cardiovascular effects produced by oral THC (20 mg) administration were determined twice in the same cannabis users: once after treatment with placebo and once after treatment with guanfacine (3 mg/day). Compared with performance at baseline, THC negatively affected accuracy on spatial working memory trials while participants were maintained on placebo (p=0.012) but not guanfacine (p=0.497); compared with placebo, accuracy was significantly (p=0.003, Cohen's d=-0.640) improved while individuals were treated with guanfacine. Similarly, compared with baseline, THC increased omission errors on an attentional task while participants were maintained on placebo (p=0.017) but not on guanfacine (p=0.709); compared with placebo, there were significantly (p=0.034, Cohen's d=0.838) fewer omissions while individuals were maintained on guanfacine. Although THC increased visual analog scores of subjective effects and heart rate, these increases were similar during treatment with placebo and guanfacine. THC did not significantly affect performance of a recognition memory task or blood pressure while individuals were maintained on either treatment. Although preliminary, these results suggest that guanfacine warrants further testing as a potential treatment for cannabis-induced cognitive deficits.
John C Churchwell
Full Text Available Anticipating future outcomes is central to decision making and a failure to consider long-term consequences may lead to impulsive choices. Adolescence is a vulnerable period during which underdeveloped prefrontal cortical systems may contribute to poor judgment, impulsive choices, and substance abuse. Conversely, substance abuse during this period may alter neural systems involved in decision making and lead to greater impulsivity. Although a broad neural network which supports decision making undergoes extensive change during adolescent development, one region that may be critical is the medial prefrontal cortex. Altered functional integrity of this region may be specifically related to reward perception, substance abuse, and dependence. In the present investigation, we acquired structural magnetic resonance images (MRI, using a 3T Siemens Trio scanner, from 18 cannabis abusing adolescents (CA; 2 female and 16 male subjects; mean age, 17.7 years; range 16-19 years and 18 healthy controls (HC; 6 female and 12 male subjects; mean age, 17.2 years; range 16-19 years. In order to measure medial orbital prefrontal cortex (moPFC morphology related to substance abuse and impulsivity, semi-automated cortical reconstruction and volumetric segmentation of MRIs was performed with FreeSurfer. Impulsivity was evaluated with the Barratt Impulsiveness Scale (BIS. Our results indicate that cannabis abusing adolescents have decreased right moPFC volume compared to controls, p =.01, d = .92, CI.95 = .21, 1.59. Cannabis abusing adolescents also show decreased future orientation, as indexed by the BIS nonplanning subscale, when compared to controls, p = .01, d = .89, CI.95 = .23, 1.55. Moreover, total moPFC volume was positively correlated with age of first use (18 = .49, p < .03, suggesting that alterations in this region may be related to initiation of cannabis use or that early initiation may lead to reduced moPFC volume.
That cannabis use may provoke mental disturbances is well known to Scandinavian psychiatrists today. A review of the psychiatric aspects of cannabis use is given, and the clinical signs of 70 cases of cannabis psychoses collected in Sweden are described. The bluntness and "amotivation" following chronic cannabis use are discussed. Anxiety reactions, flashbacks, dysphoric reactions and an abstinence syndrome are all sequels of cannabis use. Three risk groups begin to emerge: a) Young teenage cannabis users who lose some of their capacity to learn complex functions and who flee from reality to a world of dreams. With its sedative effect, cannabis could modify such emotions as anger and anxiety and slow down the liberation process of adolescence. b) Heavy daily users, often persons who cannot cope with depression or their life circumstances. c) Psychiatric patients whose resistance to relapses into psychotic reactions might be diminished according to the psychotropic effects of cannabis.
van der Pol, Peggy; Liebregts, Nienke; de Graaf, Ron; Korf, Dirk J.; van den Brink, Wim; van Laar, Margriet
Frequent cannabis users are at high risk of dependence, still most (near) daily users are not dependent. It is unknown why some frequent users develop dependence, whereas others do not. This study aims to identify predictors of first-incidence DSM-IV cannabis dependence in frequent cannabis users. A
Mary P. Becker
Full Text Available Diffusion tensor imaging (DTI studies of cannabis users report alterations in brain white matter microstructure, primarily based on cross-sectional research, and etiology of the alterations remains unclear. We report findings from longitudinal voxelwise analyses of DTI data collected at baseline and at a 2-year follow-up on 23 young adult (18–20 years old at baseline regular cannabis users and 23 age-, sex-, and IQ-matched non-using controls with limited substance use histories. Onset of cannabis use was prior to age 17. Cannabis users displayed reduced longitudinal growth in fractional anisotropy in the central and parietal regions of the right and left superior longitudinal fasciculus, in white matter adjacent to the left superior frontal gyrus, in the left corticospinal tract, and in the right anterior thalamic radiation lateral to the genu of the corpus callosum, along with less longitudinal reduction of radial diffusion in the right central/posterior superior longitudinal fasciculus, corticospinal tract, and posterior cingulum. Greater amounts of cannabis use were correlated with reduced longitudinal growth in FA as was relatively impaired performance on a measure of verbal learning. These findings suggest that continued heavy cannabis use during adolescence and young adulthood alters ongoing development of white matter microstructure, contributing to functional impairment.
Clingan, Sarah E; Woodruff, Susan I
Medical care in the emergency department (ED) is a growing and complex area of outpatient care, with about 256 visits made to EDs every minute in 2013. Studies report that, compared to people who do not use drugs, people who use illicit drugs are more likely to use the ED for their medical care. Self-efficacy has been shown to be a predictor of abstinence or reduced use among drug-using individuals. The current study describes drug avoidance self-efficacy among exclusive cannabis-using individuals and other drug-using individuals who use the ED for any reason. Participants were 693 adult patients visiting the trauma units and EDs of two large urban "safety net" hospitals (i.e., providing care to low-income, uninsured, and vulnerable population) in Southern California who reported using illicit drugs in the past 30 days. For people who use only cannabis, higher drug-avoidance self-efficacy was associated with older age, lower drug involvement scores, lower drug severity scores, and higher readiness to change use. For people who use other drugs, higher drug avoidance self-efficacy scores was associated with lower drug severity scores, lower psychiatric severity scores, higher medical severity scores, and higher readiness to change use. This study identified several factors (some common, some unique) related to higher drug-avoidance self-efficacy for both groups. Results may be important when designing intervention protocols for use in the ED.
Elizabeth Clare Temple
Full Text Available While a growing number of researchers are embracing Internet-based data collection methods, the adoption of Internet-based recruitment methods has been relatively slow. This may be because little is known regarding the relative strengths and weaknesses of different methods of Internet-based participant recruitment, nor how these different recruitment strategies impact on the data collected. These issues are addressed in this article with reference to a study comparing the effectiveness of three Internet-based strategies in recruiting cannabis users for an online study. Consideration of the recruitment data leads us to recommend that researchers use multipronged Internet-based recruitment campaigns with appropriately detailed recruitment messages tailored to the population of interest and located carefully to ensure they reach the intended audience. Further, we suggest that building rapport directly with potential participants, or utilising derived rapport and implicit endorsements, is an important aspect of successful Internet-based participant recruitment strategies.
Järvinen, Margaretha; Ravn, Signe
A considerable part of today's sociological research on recreational drug use is (explicitly or implicitly) inspired by Howard Becker's classical model of deviant careers. The aim of the present paper is to directly apply Becker's theory to empirical data on present-day cannabis use and to suggest...... in treatment for cannabis problems in Copenhagen, Denmark. We suggest a revision of Becker's career model in relation to four aspects: initiation of cannabis use, differentiation between socially integrated and individualised, disintegrated use, social control from non-users, and the users' moral stance...... on cannabis. A central point of the paper is that social interaction may both motivate cannabis use, as Becker proposed, and serve as a protective factor against extensive, problematic use....
Järvinen, Margaretha; Ravn, Signe
This article analyses the relationship between cannabis use and educational trajectories among 42 young drug users, recruited at addiction treatment centres in Denmark. Quantitative research shows regular cannabis use to be associated with poor school performance and drop-out. However, these studies do not pay much attention to differences between…
Dawkins, Lynne; Corcoran, Olivia
Electronic cigarettes are becoming increasingly popular among smokers worldwide. Commonly reported reasons for use include the following: to quit smoking, to avoid relapse, to reduce urge to smoke, or as a perceived lower-risk alternative to smoking. Few studies, however, have explored whether electronic cigarettes (e-cigarettes) deliver measurable levels of nicotine to the blood. This study aims to explore in experienced users the effect of using an 18-mg/ml nicotine first-generation e-cigarette on blood nicotine, tobacco withdrawal symptoms, and urge to smoke. Fourteen regular e-cigarette users (three females), who are abstinent from smoking and e-cigarette use for 12 h, each completed a 2.5 h testing session. Blood was sampled, and questionnaires were completed (tobacco-related withdrawal symptoms, urge to smoke, positive and negative subjective effects) at four stages: baseline, 10 puffs, 60 min of ad lib use and a 60-min rest period. Complete sets of blood were obtained from seven participants. Plasma nicotine concentration rose significantly from a mean of 0.74 ng/ml at baseline to 6.77 ng/ml 10 min after 10 puffs, reaching a mean maximum of 13.91 ng/ml by the end of the ad lib puffing period. Tobacco-related withdrawal symptoms and urge to smoke were significantly reduced; direct positive effects were strongly endorsed, and there was very low reporting of adverse effects. These findings demonstrate reliable blood nicotine delivery after the acute use of this brand/model of e-cigarette in a sample of regular users. Future studies might usefully quantify nicotine delivery in relation to inhalation technique and the relationship with successful smoking cessation/harm reduction.
Wan, Li; Baldridge, Robyn M; Colby, Amanda M; Stanford, Matthew S
Intensity dependence is an electrophysiological measure of intra-individual stability of the augmenting/reducing characteristic of N1/ P2 event-related potential amplitudes in response to stimuli of varying intensities. Abstinent ecstasy users typically show enhanced intensity dependence and higher levels of impulsivity and aggression. Enhanced intensity dependence and high impulsivity and aggression levels may be due to damage in the brain's serotonergic neurons as a result of ecstasy use. The present study investigated whether intensity dependence, impulsivity and aggression history can be used as indicators of previous chronic ecstasy usage. Forty-four abstinent polydrug users (8 women; age 19 to 61 years old) were recruited. All participants were currently residents at a local substance abuse facility receiving treatment and had been free of all drugs for a minimum of 21 days. The study found significantly enhanced intensity dependence of tangential dipole source activity and a history of more aggressive behavior in those who had previously been involved in chronic ecstasy use. Intensity dependence of the tangential dipole source and aggressive behavior history correctly identified 73.3% of those who had been regular ecstasy users and 78.3% of those who had not. Overall, 76.3% of the participants were correctly classified.
Smucker Barnwell, Sara; Earleywine, Mitch; Gordis, Elana B
The link between cannabis use and cannabis dependence remains poorly understood. Some people use cannabis regularly without signs of dependence; others show dependence despite using less. This study examined alcohol consumption as a moderator of this association. A sample of 476 people (primarily Caucasian men) who used cannabis at least once per week reported their alcohol consumption, cannabis use, and cannabis dependence symptoms in an Internet survey. Regressions revealed significant interactions between measures of cannabis use and alcohol consumption when predicting cannabis dependence. Cannabis use covaried with cannabis dependence, particularly in people who consumed alcohol frequently or in large amounts per week. Despite limitations, these data suggest that alcohol may decrease the safety of cannabis consumption. Copyright 2005 APA, all rights reserved.
Wright, A; Terry, P
Many previous studies have reported that alcohol and cannabis produce additive psychomotor effects in acute combination, but few have explicitly tested whether chronic exposure to cannabis, in the absence of acute administration, alters the effects of alcohol on psychomotor performance. To test whether long-term cannabis use modulates the effects of alcohol on psychomotor skills and self-reported mood and sensation. Regular cannabis users (minimum: daily use for at least 3 years) and infrequent users (maximum: once-monthly use for at most 3 years) were matched for sex, age, alcohol intake and other drug use (14 participants in each group). Participants received alcohol (females 0.35 g/kg; males 0.45 g/kg) and placebo drinks. By urinalysis, only regular users tested positive for metabolites of Delta(9)-tetrahydrocannabinol; breath alcohol levels were similar between groups. Participants were tested on a computerised tracking task that has been used to screen drugs for adverse effects on driving. The task involved tracking a moving target on a computer screen while simultaneously responding to occasional presentations of stimuli in the periphery of the screen. Tracking accuracy was similar for both groups after placebo, but alcohol caused a significant deterioration in performance among infrequent cannabis users relative to regular users. These changes were mirrored by significant changes in self-reported scores for dizziness, measured by visual analogue scales. Alcohol slowed reaction times, but not differentially between groups. For psychomotor skills relevant to driving, chronic cannabis use (in the absence of acute administration) does not potentiate the effects of alcohol. In fact, the superior tracking accuracy of regular users relative to infrequent users after alcohol, and their lower scores for dizziness, suggest that chronic cannabis use may instead confer cross-tolerance to specific effects of alcohol on behaviour.
The acute side effects caused by cannabis use are mainly related to psyche and cognition, and to circulation. Euphoria, anxiety, changes in sensory perception, impairment of memory and psychomotor performance are common effects after a dose is taken that exceeds an individually variable threshold. Cannabis consumption may increase heart rate and change blood pressure, which may have serious consequences in people with heart disease. Effects of chronic use may be induction of psychosis and development of dependency to the drug. Effects on cognitive abilities seem to be reversible after abstinence, except possibly in very heavy users. Cannabis exposure in utero may have negative consequences on brain development with subtle impairment of cognitive abilities in later life. Consequences of cannabis smoking may be similar to those of tobacco smoking and should be avoided. Use by young people has more detrimental effects than use by adults. There appear to be promising therapeutic uses of cannabis for a range of indications. Use of moderate doses in a therapeutic context is usually not associated with severe side effects. Current prohibition on cannabis use may also have harmful side effects for the individual and the society, while having little influence on prevalence of use. Harm is greatest for seriously ill people who may benefit from a treatment with cannabis. This makes it difficult to justify criminal penalties against patients.
Kinner, Stuart A; George, Jessica; Johnston, Jennifer; Dunn, Matthew; Degenhardt, Louisa
A significant proportion of young Australians engage in risky alcohol consumption, and an increasing minority are regular ecstasy (3,4-methylenedioxymethamphetamine) users. Risky alcohol use, alone or in combination with ecstasy, is associated with a range of acute and chronic health risks. The aim of this study was to document the incidence and some health-related correlates of alcohol use, and concurrent alcohol and ecstasy use, among a large, national sample of regular ecstasy users (REU) in Australia. National, cross-sectional surveys of REU in Australia 2003-2008. Among REU in 2008 (n=678) usual alcohol use, psychological distress and health-related quality of life were measured using the Alcohol Use Disorders Identification Test, Kessler Psychological Distress Scale and Short Form-8 Survey respectively. Among REU in 2008, 36% reported high-risk patterns of usual alcohol consumption, 62% reported usually consuming more than five standard drinks with ecstasy, and 24% reported currently experiencing high or very high levels of psychological distress. Controlling for age and education, high-risk drinking among REU was associated with higher levels of psychological distress and poorer health-related functioning; however, the associations between concurrent alcohol and ecstasy use, and health outcomes, were not significant (P>0.05). A large and increasing proportion of REU in Australia engage in high-risk patterns of alcohol consumption, including in combination with ecstasy. High-risk alcohol consumption among this group is associated with adverse health-related outcomes. Prevention and harm reduction interventions for REU should incorporate messages about the risks associated with alcohol use. There is an ongoing need for youth-specific, coordinated alcohol and other drug and mental health services. © 2011 Australasian Professional Society on Alcohol and other Drugs.
Lafaye, Genevieve; Karila, Laurent; Blecha, Lisa; Benyamina, Amine
Cannabis (also known as marijuana) is the most frequently used illicit psychoactive substance in the world. Though it was long considered to be a "soft" drug, studies have proven the harmful psychiatric and addictive effects associated with its use. A number of elements are responsible for the increased complications of cannabis use, including the increase in the potency of cannabis and an evolution in the ratio between the two primary components, Δ 9 -tetrahydrocannabinol (Δ 9 -THC) and cannabidiol (toward a higher proportion of Δ 9 -THC), Synthetic cannabinoid (SC) use has rapidly progressed over the last few years, primarily among frequent cannabis users, because SCs provide similar psychoactive effects to cannabis. However, their composition and pharmacological properties make them dangerous substances. Cannabis does have therapeutic properties for certain indications. These therapeutic applications pertain only to certain cannabinoids and their synthetic derivatives. The objective of this article is to summarize current developments concerning cannabis and the spread of SCs. Future studies must further explore the benefit-risk profile of medical cannabis use.
Creswell, Kasey G; Chung, Tammy; Clark, Duncan B; Martin, Christopher S
Most adolescent cannabis use occurs in social settings among peers. Solitary cannabis use during adolescence may represent an informative divergence from normative behavior with important implications for understanding risk for cannabis problems. This longitudinal study examined associations of adolescent solitary cannabis use with levels of cannabis use and problems in adolescence and in young adulthood. Cannabis using-adolescents aged 12-18 were recruited from clinical programs (n=354; 43.8% female; 83.3% Caucasian) and community sources (n=93; 52.7% female; 80.6% Caucasian). Participants reported on cannabis use patterns and diagnostic symptoms at baseline and multiple follow-ups into young adulthood. Compared to social-only users, adolescent solitary cannabis users were more likely to be male and reported more frequent cannabis use and more DSM-IV cannabis use disorder (CUD) symptoms. Regression analyses showed that solitary cannabis use in adolescence predicted CUD symptom counts in young adulthood (age 25) after controlling for demographic variables and the frequency of adolescent cannabis use. However, solitary adolescent cannabis use was no longer predictive of age 25 CUD symptoms after additionally controlling for adolescent CUD symptoms. Solitary cannabis use is associated with greater cannabis use and problems during adolescence, but evidence is mixed that it predicts young adult cannabis problems. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Best, David; Gross, Samantha; Manning, Victoria; Gossop, Michael; Witton, John; Strang, John
The study uses a school-based sample to test the social and familial risk and protective factors relating to cannabis use. Based on a self-completion survey of 2078 14-16-year-olds (mean age of 15 years) attending seven standard state-run secondary schools in south London, an assessment was made of rates and risk factors for cannabis use. Twenty-four per cent of the total sample had ever used cannabis, with 15% having done so in the month prior to assessment. In addition to greater likelihood of illicit drug use, lifetime cannabis users were less likely to spend time regularly with both their mothers and fathers, but more likely to spend free time with friends who smoked, drank alcohol and used illicit drugs, and with friends involved in criminal activities. Among those who had ever used cannabis, frequency of cannabis use was predicted (using linear regression) by two onset factors (earlier initiation of drinking and cannabis use were both linked to more frequent use) and two social factors (more time spent with drug-using friends and less time spent with the mother). Overall, the study showed that early onset, itself predicted by social networks, is linked to more frequent use of cannabis and that this appears to be sustained by less time spent with parents and more with drug-using peers.
Cosker, E; Schwitzer, T; Ramoz, N; Ligier, F; Lalanne, L; Gorwood, P; Schwan, R; Laprévote, V
Cannabis is one of the most widely-used drugs in industrialized countries. It is now well established that cannabis use impacts neurocognition. In the intoxication period time episodic memory, working memory and attention are impacted and impulsivity is increased. The long-term effects of cannabis use tend to be similar. Various internal factors, such as sex differences, modulate this impact. It is unclear whether genetic variations can also influence the impact of cannabis on neurocognition. We set out to examine the impact of genetic variations on neurocognition in cannabis users. We conducted a search via the PubMed, Web of Science, and ScienceDirect databases to identify studies measuring neurocognition and assessing genotypes in the context of cannabis use. We included 13 articles. We found that working memory, verbal and visual memory and sustained attention are more impacted during intoxication in subjects with the Val COMT allele. COMT gene could also modulate sustained attention in regular use. The CNR1, AKT1, DBH and 5-HTT/SLC6A4 genes may also modulate effects. Most of these genes are linked to schizophrenia. A fuller understanding of their impact on the effects of cannabis on neurocognition would thus help elucidate the mechanisms linking cannabis and psychosis. However, evidence is still scant, and more research is needed. Copyright © 2017. Published by Elsevier Inc.
Breen, Courtney; Roxburgh, Amanda; Degenhardt, Louisa
Previous research has found that female injecting drug users (IDU) are younger and more likely to be involved in risky behaviours such as needle sharing and sex work than male IDU. Aboriginal female drug users, in particular, are over-represented in IDU and prison populations. These factors place female IDU at increased risk of health problems and complicate issues such as homelessness, unemployment and poverty. Although a substantial body of research exists, little trend analysis has been done in Australia and much of the previous literature has focused on treatment populations. Cross-sectional data from 1996 to 2003 from regular IDU in Sydney interviewed as part of Australia's drug monitoring system, the Illicit Drug Reporting System (IDRS) were examined for trends over time. The demographic characteristics, drug use patterns and self-reported risk behaviours of the most recent sample (2003) were analysed for gender differences. Female IDU were younger in all sample years. Female IDU were more likely to identify as Aboriginal or Torres Strait Islander (ATSI) and engage in sex work. There has been a steady increase in these proportions over time. Female IDU were less likely to have a prison history, although there has been an increase among both male and female IDU over time. There were no gender differences in drug use patterns or frequency of drug use. Larger proportions of females report lending needles. Reports of lending and borrowing needles have decreased over time among both male and female IDU. Female IDU may place themselves at greater risk than male IDU by being more likely to share injecting equipment and engage in sex work. Treatment and other measures to reduce harm may need to be targeted specifically at women and, in particular, indigenous women.
Cannabis is the most widely used illicit drug. Part of ever-users become frequent users and continue to use over a longer period. 600 frequent users (18-30 years) were enrolled in a 3-year longitudinal study. Trajectories of frequent cannabis use and cannabis dependence appeared very dynamic.
Soyka, M; Preuss, U; Hoch, E
Use and misuse of cannabis and marihuana are frequent. About 5% of the adult population are current users but only 1.2% are dependent. The medical use of cannabis is controversial but there is some evidence for improvement of chronic pain and spasticity. The somatic toxicity of cannabis is well proven but limited and psychiatric disorders induced by cannabis are of more relevance, e.g. cognitive disorders, amotivational syndrome, psychoses and delusional disorders as well as physical and psychological dependence. The withdrawal symptoms are usually mild and do not require pharmacological interventions. To date there is no established pharmacotherapy for relapse prevention. Psychosocial interventions include psychoeducation, behavioral therapy and motivational enhancement. The CANDIS protocol is the best established German intervention among abstinence-oriented therapies.
Jouanjus, Emilie; Raymond, Valentin; Lapeyre-Mestre, Maryse; Wolff, Valérie
The purpose of the study was to examine the published evidence on the cardiovascular risk related to the use of cannabis-based products by performing a systematic review of recent literature. The World Health Organization (WHO) emphasizes that cannabis use represents a risky behavior as it may lead to many adverse effects, and in particular, cardiovascular effects. A systematic review of articles published between January 1, 2011 and May 31, 2016 was performed in agreement with the PRISMA statement. Articles presenting data on humans exposed to cannabis-based products and suffering from any cardiovascular condition were eligible for inclusion. The inclusion process was based on a search algorithm and performed in a blinded standardized manner. Overall, 826 articles were found in the literature search, 115 of which remained after performing the inclusion procedure. These were 81 case reports, 29 observational studies, 3 clinical trials, and 2 experimental studies. A total of 116 individuals was the subject of case reports. The mean age was 31 years (95%CI = 29-34), and patients were more frequently men (81.9%) than women (18.1%). They mainly suffered from ischemic strokes or myocardial infarctions. Data provided by the 29 included observational studies evidenced an association between exposure to cannabis-based products and cardiovascular disease. Currently, this evidence is stronger for ischemic strokes than for any other cardiovascular diseases. While the data are limited, there is some suggestion that cannabis use may have negative cardiovascular consequences, particularly at large doses.
Sundström, Mira; Pelander, Anna; Simojoki, Kaarlo; Ojanperä, Ilkka
The most severe consequences of drug abuse include infectious diseases, overdoses, and drug-related deaths. As the range of toxicologically relevant compounds is continually changing due to the emergence of new psychoactive substances (NPS), laboratories are encountering analytical challenges. Current immunoassays are insufficient for determining the whole range of the drugs abused, and a broad-spectrum screening method is therefore needed. Here, the patterns of drug abuse in two groups of drug users were studied from urine samples using a comprehensive screening method based on high-resolution time-of-flight mass spectrometry. The two groups comprised drug abusers undergoing opioid maintenance treatment (OMT) or drug withdrawal therapy and routinely visiting a rehabilitation clinic, and drug abusers with irregular attendance at a harm reduction unit (HRU) and suspected of potential NPS abuse. Polydrug abuse was observed in both groups, but was more pronounced among the HRU subjects with a mean number of concurrent drugs per sample of 3.9, whereas among the regularly treated subjects the corresponding number was 2.1. NPS and pregabalin were more frequent among HRU subjects, and their abuse was always related to drug co-use. The most common drug combination for an HRU subject included amphetamine, cannabis, buprenorphine, benzodiazepine, and alpha-pyrrolidinovalerophenone. A typical set of drugs for treated subjects was buprenorphine, benzodiazepine, and occasionally amphetamine. Abuse of several concurrent drugs poses a higher risk of drug intoxication and a threat of premature termination of OMT. Since the subjects attending treatment used fewer concurrent drugs, this treatment could be valuable in reducing polydrug abuse. Copyright © 2015 John Wiley & Sons, Ltd.
Korf, Dirk J
Conflicting predictions have been made to the influence of decriminalization on cannabis use. Prohibitionists forecast that decriminalization will lead to an increase in consumption of cannabis, while their opponents hypothesise that cannabis use will decline after decriminalization. Most probably cannabis use in the Netherlands so far evolved in two waves, with a first peak around 1970, a low during the late 1970s and early 1980s, and a second peak in the mid-1990s. It is striking that this trend in cannabis use among youth in the Netherlands rather parallels four identified stages in the availability of cannabis. The number of cannabis users peaked when the cannabis was distributed through an underground market (late 1960s and early 1970s). Then the number decreased as house dealers were superseeding the underground market (1970s), and went up again after coffee shops took over the sale of cannabis (1980s), and stabilised or slightly decreased by the end of the 1990s when the number of coffee shops was reduced. Although changes in cannabis policy went along with changes in availability of cannabis and prevalence of cannabis use, it is questionable whether changes in cannabis policy were causally related to trends in cannabis use. Cannabis use also developed in waves in other European countries that did not decriminalize cannabis, as well as in the US. Consequently, trends in cannabis use seem to develop rather independently of cannabis policy.
Bosker, Wendy M; Kuypers, Kim P C; Theunissen, Eef L; Surinx, Anke; Blankespoor, Roos J; Skopp, Gisela; Jeffery, Wayne K; Walls, H Chip; van Leeuwen, Cees J; Ramaekers, Johannes G
The acute and chronic effects of dronabinol [medicinal Δ(9) -tetrahydrocannabinol (THC)] on actual driving performance and the Standard Field Sobriety Test (SFST) were assessed. It was hypothesized that occasional users would be impaired on these tests and that heavy users would show less impairment due to tolerance. Double-blind, placebo-controlled, randomized, three-way cross-over study. Twelve occasional and 12 heavy cannabis users (14 males/10 females) received single doses of placebo, 10 and 20 mg dronabinol. Standard deviation of lateral position (SDLP; i.e. weaving) is the primary measure of road-tracking control. Time to speed adaptation (TSA) is the primary reaction-time measure in the car-following test. Percentage of impaired individuals on the SFST and subjective high on a visual analogue scale were secondary measures. Superiority tests showed that SDLP (P = 0.008) and TSA (P = 0.011) increased after dronabinol in occasional users. Equivalence tests demonstrated that dronabinol-induced increments in SDLP were bigger than impairment associated with BAC of 0.5 mg/ml in occasional and heavy users, although the magnitude of driving impairment was generally less in heavy users. The SFST did not discriminate between conditions. Levels of subjective high were comparable in occasional and heavy users. Dronabinol (medicinal tetrahydrocannabinol) impairs driving performance in occasional and heavy users in a dose-dependent way, but to a lesser degree in heavy users due possibly to tolerance. The Standard Field Sobriety Test is not sensitive to clinically relevant driving impairment caused by oral tetrahydrocannabinol. © 2012 The Authors. Addiction © 2012 Society for the Study of Addiction.
van der Pol, P.; Liebregts, N.; de Graaf, R.; Korf, D.J.; van den Brink, W.; van Laar, M.
Background Frequent cannabis users are at high risk of dependence, still most (near) daily users are not dependent. It is unknown why some frequent users develop dependence, whereas others do not. This study aims to identify predictors of first-incidence DSM-IV cannabis dependence in frequent
The cannabis plant has been known to humanity for centuries as a remedy for pain, diarrhea and inflammation. Current research is inspecting the use of cannabis for many diseases, including multiple sclerosis, epilepsy, dystonia, and chronic pain. In inflammatory conditions cannabinoids improve pain in rheumatoid arthritis and:pain and diarrhea in Crohn's disease. Despite their therapeutic potential, cannabinoids are not free of side effects including psychosis, anxiety, paranoia, dependence and abuse. Controlled clinical studies investigating the therapeutic potential of cannabis are few and small, whereas pressure for expanding cannabis use is increasing. Currently, as long as cannabis is classified as an illicit drug and until further controlled studies are performed, the use of medical cannabis should be limited to patients who failed conventional better established treatment.
Buckner, Julia D; Zvolensky, Michael J
Social anxiety appears to be a risk factor for cannabis-related problems. Socially anxious individuals are vulnerable to using cannabis to cope in social situations and to avoiding social situations if marijuana is unavailable. Yet, the relative impact of cannabis use to cope with social anxiety relative to use to cope with negative affect more broadly has yet to be examined. The present study used the Marijuana to Cope with Social Anxiety Scale (MCSAS) to examine the incremental validity of using cannabis use to cope in social situations (MCSAS-Cope) and avoidance of social situations if cannabis is unavailable (MCSAS-Avoid) in a community-recruited sample of 123 (34.1% female) current cannabis users. After controlling for age of first cannabis use, gender, alcohol and tobacco use, other cannabis use motives, and cannabis expectancies, MCSAS-Cope remained significantly positively related to cannabis use frequency and cannabis-related problems. After controlling for age of first cannabis use, gender, alcohol and tobacco use, and experiential avoidance, MCSAS-Avoid remained significantly related to cannabis problems but not frequency. The present findings suggest that cannabis use to manage social forms of anxiety may be important to understanding cannabis use behaviors. The current findings identify cognitive/motivational factors implicated in more frequent cannabis use and in cannabis-related impairment, which may be essential to inform efforts to further refine prevention and treatment efforts. © American Academy of Addiction Psychiatry.
Van der Meersch, H; Verschuere, A P; Bottriaux, F
Pharmaceutical grade cannabis is available to Dutch patients from public pharmacies in the Netherlands. The first part of this paper reviews the pharmaceutical and pharmacological properties of medicinal cannabis. Detailed information about its composition and quality, potential applications, methods of administration, adverse reactions, drug interactions and safety during pregnancy or breastfeeding are given. The second part deals with the legal aspects of dispensing medicinal cannabis through pharmacies in view of the Belgian and Dutch legislation. The last part discusses the present Belgian regulation about the possession of cannabis.
El Omri, Naoual; Eljaoudi, Rachid; Mekouar, Fadwa; Jira, Mohammed; Sekkach, Youssef; Amezyane, Taoufik; Ghafir, Driss
Cannabis is the most consumed psychoactive substance by young people. Chronic use of cannabis can lead to cannabis arteritis, which is a very rare peripheral vascular disease similar to Buerger's disease. It is affecting young adults, especially men, consuming cannabis. A 27-year old woman, with no particular past medical history except for long-term use of cannabis and tobacco developed a digital necrosis in the left hand. She denied using other illicit drugs. Doppler ultrasound examination of the upper limbs was unremarkable. Toxicological analysis revealed the presence of cannabis in both biological fluid and hair strand. Despite medical treatment, cessation of the cannabis and tobacco consumption and hyperbaric oxygen therapy, an amputation of necrotic parts was then required. This case shows the prolonged use of cannabis could be a risk factor for young adult arteritis. Faced with a rapidly progressive arteritis occurring in young adult, the physician should consider the history of use of cannabis. Hair analysis can be useful for confirmation of the chronic consumption of drugs.
Shi, Yuyan; Lenzi, Michela; An, Ruopeng
Aims To assess the associations between types of cannabis control policies at country level and prevalence of adolescent cannabis use. Setting, Participants and Design Multilevel logistic regressions were performed on 172,894 adolescents 15 year of age who participated in the 2001/2002, 2005/2006, or 2009/2010 cross-sectional Health Behaviour in School-Aged Children (HBSC) survey in 38 European and North American countries. Measures Self-reported cannabis use status was classified into ever use in life time, use in past year, and regular use. Country-level cannabis control policies were categorized into a dichotomous measure (whether or not liberalized) as well as 4 detailed types (full prohibition, depenalization, decriminalization, and partial prohibition). Control variables included individual-level sociodemographic characteristics and country-level economic characteristics. Findings Considerable intra-class correlations (.15-.19) were found at country level. With respect to the dichotomized cannabis control policy, adolescents were more likely to ever use cannabis (odds ratio (OR) = 1.10, p = .001), use in past year (OR = 1.09, p = .007), and use regularly (OR = 1.26, p = .004). Although boys were substantially more likely to use cannabis, the correlation between cannabis liberalization and cannabis use was smaller in boys than in girls. With respect to detailed types of policies, depenalization was associated with higher odds of past-year use (OR = 1.14, p = .013) and regular use (OR = 1.23, p = .038), and partial prohibition was associated with higher odds of regular use (OR = 2.39, p = .016). The correlation between cannabis liberalization and regular use was only significant after the policy had been introduced for more than 5 years. Conclusions Cannabis liberalization with depenalization and partial prohibition policies was associated with higher levels of regular cannabis use among adolescents. The correlations were heterogeneous between genders and
Vredeveldt, Annelies; Charman, Steve D.; den Blanken, Aukje; Hooydonk, Maren
Eyewitnesses to crimes are regularly under the influence of drugs, such as cannabis. Yet there is very little research on how the use of cannabis affects eyewitness memory. In the present study, we assessed the effects of cannabis on eyewitness recall and lineup identification performance in a field
Gray, Kevin M; Riggs, Paula D; Min, Sung-Joon; Mikulich-Gilbertson, Susan K; Bandyopadhyay, Dipankar; Winhusen, Theresa
Cigarette smoking is common in adolescents with attention-deficit/hyperactivity disorder (ADHD) and substance use disorders (SUD). However, little is known about the relationship between cigarette and cannabis use trajectories in the context of treatment for both ADHD and SUD. To address this research gap, we report collateral analyses from a 16-week randomized, controlled trial (n=303) of osmotic-release methylphenidate (OROS-MPH) in adolescents with ADHD concurrently receiving cognitive behavioral therapy (CBT) targeting non-nicotine SUD. Participants completed cigarette and cannabis use self-report at baseline and throughout treatment. Analyses were performed to explore the relationships between cigarette smoking, cannabis use, and other factors, such as medication treatment assignment (OROS-MPH versus placebo). Baseline (pre-treatment) cigarette smoking was positively correlated with cannabis use. Negligible decline in cigarette smoking during treatment for non-nicotine SUD was observed in both medication groups. Regular cigarette and cannabis users at baseline who reduced their cannabis use by >50% also reduced cigarette smoking (from 10.8±1.1 to 6.2±1.1 cigarettes per day). Findings highlight the challenging nature of concurrent cannabis and cigarette use in adolescents with ADHD, but demonstrate that changes in use of these substances during treatment may occur in parallel. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Full Text Available People with schizophrenia frequently report cannabis use, and cannabis may be a risk factor for schizophrenia, mediated through effects on brain function and biochemistry. Thus, it is conceivable that cannabis may also influence cognitive functioning in this patients group. We report data from our own laboratory on the use of cannabis by schizophrenia patients, and review the existing literature on the effects of cannabis on cognition in schizophrenia and related psychosis. Of the 23 studies that were found, 14 reported that the cannabis users had better cognitive performance than the schizophrenia non-users. Eight studies reported no or minimal differences in cognitive performance in the two groups, but only one study reported better cognitive performance in the schizophrenia non-user group. Our own results confirm the overall impression from the literature review of better cognitive performance in the cannabis user group. These paradoxical findings may have several explanations, which are discussed. We suggest that cannabis causes a transient cognitive breakdown enabling the development of psychosis, imitating the typical cognitive vulnerability seen in schizophrenia. This is further supported by an earlier age of onset and fewer neurological soft signs in the cannabis-related schizophrenia group, suggesting an alternative pathway to psychosis.
Schoeler, Tabea; Petros, Natalia; Di Forti, Marta; Klamerus, Ewa; Foglia, Enrico; Murray, Robin; Bhattacharyya, Sagnik
Uncertainty exists whether the use of non-prescription psychoactive substances following onset of a first episode of psychosis (FEP), in particular cannabis use, affects medication adherence. Data from FEP patients (N=233) obtained through prospective assessments measured medication adherence and pattern of cannabis and other substance use in the first two years following onset of psychosis. Multiple logistic regression analyses were employed to compare the different substance use groups with regard to risk of medication non-adherence, while controlling for confounders. The proportion of non-adherent patients was higher in those who continued using high-potency forms of cannabis (skunk-like) following the onset (83%) when compared to never regular users (51%), corresponding to an Odds Ratio (OR) of 5.26[95% Confidence Interval (CI) 1.91-15.68]. No significant increases in risk were present in those who used cannabis more sporadically or used milder forms of cannabis (hash-like). Other substances did not make an independent contribution in this model, including cigarette use ([OR 0.88, 95% CI 0.41-1.89]), alcohol use ([OR 0.66, 95% CI 0.27-1.64]) or regular use of other illicit drugs ([OR 1.03, 95% CI 0.34-3.15]) following the onset. These results suggest that continued use of high-potency cannabis following the onset of psychosis may adversely affect medication adherence. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.
Hoff, Dominic A.; Andersen, Anette; Holstein, Bjorn E.
There is little information available on the topic of poor school satisfaction as a risk factor for cannabis use among adolescents. We examined if there was an association between poor school satisfaction, school class cannabis use and individual cannabis use. Further, we investigated if many cannabis users within the school class statistically…
Nicholas Sullivan; Sytze Elzinga; Jeffrey C. Raber
The present study was conducted in order to quantify to what extent cannabis consumers may be exposed to pesticide and other chemical residues through inhaled mainstream cannabis smoke. Three different smoking devices were evaluated in order to provide a generalized data set representative of pesticide exposures possible for medical cannabis users. Three different pesticides, bifenthrin, diazinon, and permethrin, along with the plant growth regulator paclobutrazol, which are readily available...
Ramo, Danielle E; Popova, Lucy; Grana, Rachel; Zhao, Shirley; Chavez, Kathryn
Mobile technology is pervasive and widely used to obtain information about drugs such as cannabis, especially in a climate of rapidly changing cannabis policy; yet the content of available cannabis apps is largely unknown. Understanding the resources available to those searching for cannabis apps will clarify how this technology is being used to reflect and influence cannabis use behavior. We investigated the content of 59 cannabis-related mobile apps for Apple and Android devices as of November 26, 2014. The Apple and Google Play app stores were searched using the terms "cannabis" and "marijuana." Three trained coders classified the top 20 apps for each term and each store, using a coding guide. Apps were examined for the presence of 20 content codes derived by the researchers. Total apps available for each search term were 124 for cannabis and 218 for marijuana in the Apple App Store, and 250 each for cannabis and marijuana on Google Play. The top 20 apps in each category in each store were coded for 59 independent apps (30 Apple, 29 Google Play). The three most common content areas were cannabis strain classification (33.9%), facts about cannabis (20.3%), and games (20.3%). In the Apple App Store, most apps were free (77%), all were rated "17+" years, and the average user rating was 3.9/5 stars. The most popular apps provided cannabis strain classifications (50%), dispensary information (27%), or general facts about cannabis (27%). Only one app (3%) provided information or resources related to cannabis abuse, addiction, or treatment. On Google Play, most apps were free (93%), rated "high maturity" (79%), and the average user rating was 4.1/5. The most popular app types offered games (28%), phone utilities (eg, wallpaper, clock; 21%) and cannabis food recipes (21%); no apps addressed abuse, addiction, or treatment. Cannabis apps are generally free and highly rated. Apps were most often informational (facts, strain classification), or recreational (games), likely
Salehi, Nazu; Lambert-Jensen, Mikkel Mørch; Hansen, Sebastian Lorentz; Hansen, Caroline Pulz; Nadir, Atifa Mohammad; Ernst, Line; Showiki, Omar Isac
AbstractCannabis har, blandt nogle kulturer, været værdsat for sine medicinske egenskaber i årtusinder. Formålet med denne rapport er, at undersøge de helende effekter cannabis har på cancer og multipel sclerose. Dette gør vi, ved at se på moderne forskning indenfor emnet. Endvidere vil vi prøve at forudsige, hvilke fremtidige studier der skal foretages for at opnå implementering af medicinsk cannabis, ved at bruge Rogers’ Diffusion of Innovations. VI har valgt at interviewe 3 forskellige per...
Gates, Peter J; Albertella, Lucy
The majority of Australians support a change in legislation to allow the use of cannabis for medical purposes. Despite strong public support, very little is known about the patterns of medicinal cannabis use among Australians. This study aims to gain a better understanding of Australian medicinal cannabis users and their patterns of use. The nature of calls to the Cannabis Information and Helpline (N = 15701), a free national service for Australians with concerns regarding cannabis use, were investigated to determine the number of calls made by those who inquired about the medicinal use of cannabis (N = 275) and the implied reasons for use among those who identify using cannabis in this way. The majority of medicinal cannabis inquirers mentioned cannabis to alleviate pain. Further, compared to other callers, medicinal cannabis inquirers were more likely to be male, unemployed, older, and have recently started using cannabis. These findings highlight the need for future research to better understand the issues faced by Australians regarding the use of cannabis for medicinal purposes and how they may be meaningfully addressed. Particular focus should be placed toward older, unemployed males.
Allsop, David J.; Copeland, Jan; Norberg, Melissa M.; Fu, Shanlin; Molnar, Anna; Lewis, John; Budney, Alan J.
Background and Aims Questions over the clinical significance of cannabis withdrawal have hindered its inclusion as a discrete cannabis induced psychiatric condition in the Diagnostic and Statistical Manual of Mental Disorders (DSM IV). This study aims to quantify functional impairment to normal daily activities from cannabis withdrawal, and looks at the factors predicting functional impairment. In addition the study tests the influence of functional impairment from cannabis withdrawal on cannabis use during and after an abstinence attempt. Methods and Results A volunteer sample of 49 non-treatment seeking cannabis users who met DSM-IV criteria for dependence provided daily withdrawal-related functional impairment scores during a one-week baseline phase and two weeks of monitored abstinence from cannabis with a one month follow up. Functional impairment from withdrawal symptoms was strongly associated with symptom severity (p = 0.0001). Participants with more severe cannabis dependence before the abstinence attempt reported greater functional impairment from cannabis withdrawal (p = 0.03). Relapse to cannabis use during the abstinence period was associated with greater functional impairment from a subset of withdrawal symptoms in high dependence users. Higher levels of functional impairment during the abstinence attempt predicted higher levels of cannabis use at one month follow up (p = 0.001). Conclusions Cannabis withdrawal is clinically significant because it is associated with functional impairment to normal daily activities, as well as relapse to cannabis use. Sample size in the relapse group was small and the use of a non-treatment seeking population requires findings to be replicated in clinical samples. Tailoring treatments to target withdrawal symptoms contributing to functional impairment during a quit attempt may improve treatment outcomes. PMID:23049760
David J Allsop
Full Text Available Questions over the clinical significance of cannabis withdrawal have hindered its inclusion as a discrete cannabis induced psychiatric condition in the Diagnostic and Statistical Manual of Mental Disorders (DSM IV. This study aims to quantify functional impairment to normal daily activities from cannabis withdrawal, and looks at the factors predicting functional impairment. In addition the study tests the influence of functional impairment from cannabis withdrawal on cannabis use during and after an abstinence attempt.A volunteer sample of 49 non-treatment seeking cannabis users who met DSM-IV criteria for dependence provided daily withdrawal-related functional impairment scores during a one-week baseline phase and two weeks of monitored abstinence from cannabis with a one month follow up. Functional impairment from withdrawal symptoms was strongly associated with symptom severity (p=0.0001. Participants with more severe cannabis dependence before the abstinence attempt reported greater functional impairment from cannabis withdrawal (p=0.03. Relapse to cannabis use during the abstinence period was associated with greater functional impairment from a subset of withdrawal symptoms in high dependence users. Higher levels of functional impairment during the abstinence attempt predicted higher levels of cannabis use at one month follow up (p=0.001.Cannabis withdrawal is clinically significant because it is associated with functional impairment to normal daily activities, as well as relapse to cannabis use. Sample size in the relapse group was small and the use of a non-treatment seeking population requires findings to be replicated in clinical samples. Tailoring treatments to target withdrawal symptoms contributing to functional impairment during a quit attempt may improve treatment outcomes.
Solowij, Nadia; Pesa, Nicole
Evidence that cannabis use impairs cognitive function in humans has been accumulating in recent decades. The purpose of this overview is to update knowledge in this area with new findings from the most recent literature. Literature searches were conducted using the Web of Science database up to February 2010. The terms searched were: "cannabi*" or "marijuana", and "cogniti*" or "memory" or "attention" or "executive function", and human studies were reviewed preferentially over the animal literature. Cannabis use impairs memory, attention, inhibitory control, executive functions and decision making, both during the period of acute intoxication and beyond, persisting for hours, days, weeks or more after the last use of cannabis. Pharmacological challenge studies in humans are elucidating the nature and neural substrates of cognitive changes associated with various cannabinoids. Long-term or heavy cannabis use appears to result in longer-lasting cognitive abnormalities and possibly structural brain alterations. Greater adverse cognitive effects are associated with cannabis use commencing in early adolescence. The endogenous cannabinoid system is involved in regulatory neural mechanisms that modulate processes underlying a range of cognitive functions that are impaired by cannabis. Deficits in human users most likely therefore reflect neuroadaptations and altered functioning of the endogenous cannabinoid system.
Popova, Lucy; Grana, Rachel; Zhao, Shirley; Chavez, Kathryn
Background Mobile technology is pervasive and widely used to obtain information about drugs such as cannabis, especially in a climate of rapidly changing cannabis policy; yet the content of available cannabis apps is largely unknown. Understanding the resources available to those searching for cannabis apps will clarify how this technology is being used to reflect and influence cannabis use behavior. Objective We investigated the content of 59 cannabis-related mobile apps for Apple and Android devices as of November 26, 2014. Methods The Apple and Google Play app stores were searched using the terms “cannabis” and “marijuana.” Three trained coders classified the top 20 apps for each term and each store, using a coding guide. Apps were examined for the presence of 20 content codes derived by the researchers. Results Total apps available for each search term were 124 for cannabis and 218 for marijuana in the Apple App Store, and 250 each for cannabis and marijuana on Google Play. The top 20 apps in each category in each store were coded for 59 independent apps (30 Apple, 29 Google Play). The three most common content areas were cannabis strain classification (33.9%), facts about cannabis (20.3%), and games (20.3%). In the Apple App Store, most apps were free (77%), all were rated “17+” years, and the average user rating was 3.9/5 stars. The most popular apps provided cannabis strain classifications (50%), dispensary information (27%), or general facts about cannabis (27%). Only one app (3%) provided information or resources related to cannabis abuse, addiction, or treatment. On Google Play, most apps were free (93%), rated “high maturity” (79%), and the average user rating was 4.1/5. The most popular app types offered games (28%), phone utilities (eg, wallpaper, clock; 21%) and cannabis food recipes (21%); no apps addressed abuse, addiction, or treatment. Conclusions Cannabis apps are generally free and highly rated. Apps were most often informational
Rella, Joseph G
Cannabis is widely used for a variety of reasons, and its changing legal status may foster more new users. Although the acute clinical effects of cannabis are generally benign, clinicians should be aware of health complications and testing limitations. Copyright © 2015 Cleveland Clinic.
van der Pol, P.M.
Young adults who often smoke cannabis are at higher risk of dependence, but most do not become dependent. This thesis examined the question: Which frequent cannabis users are/become/stay dependent, and seek treatment, and which do not? It was answered with a three-year prospective cohort of 600
van der Pol, P.M.
Young adults who often smoke cannabis are at higher risk of dependence, but most do not become dependent. This thesis examined the question: Which frequent cannabis users are/become/stay dependent, and seek treatment, and which do not? It was answered with a three-year prospective cohort of 600 young adults (18-30 years) who used cannabis frequently (≥3 days weekly for >1 year), distinguishing users with and without dependence; comparisons with non-users and patients in treatment; and ‘natura...
Anthony, James C; Lopez-Quintero, Catalina; Alshaarawy, Omayma
Globally, the most widely used set of compounds among the internationally regulated drugs is cannabis. To review evidence from epidemiological research on cannabis, organized in relation to this field's five main rubrics: quantity, location, causes, mechanisms, and prevention/ control. The review covers a selection of evidence from standardized population surveys, official statistics, and governmental reports, as well as published articles and books identified via MEDLINE, Web of Science, and Google Scholar as of July 2016. In relation to quantity, an estimated 3% to 5% of the world population is thought to have tried a cannabis product, with at least one fairly recent use, mainly extra-medical and outside boundaries of prescribed use. Among cannabis users in the United States, roughly one in 7-8 has engaged in medical marijuana use. In relation to location, prevalence proportions reveal important variations across countries and between subgroups within countries. Regarding causes and mechanisms of starting to use cannabis, there is no compelling integrative and replicable conceptual model or theoretical formulation. Most studies of mechanisms have focused upon a 'gateway sequence' and person-to-person diffusion, with some recent work on disability-adjusted life years. A brief review of cannabis use consequences, as well as prevention and control strategies is also provided. At present, we know much about the frequency and occurrence of cannabis use, with too little replicable definitive evidence with respect to the other main rubrics. Given a changing regulatory environment for cannabis products, new institutions such as an independent International Cannabis Products Safety Commission may be required to produce evidence required to weigh benefits versus costs. It is not clear that governmentsponsored research will be sufficient to meet consumer demand for balanced points of view and truly definitive evidence. Copyright© Bentham Science Publishers; For any queries
Anthony, James C.; Lopez-Quintero, Catalina; Alshaarawy, Omayma
Background Globally, the most widely used set of compounds among the internationally regulated drugs is cannabis. Objective To review evidence from epidemiological research on cannabis, organized in relation to this field’s five main rubrics: quantity, location, causes, mechanisms, and prevention/control. Method The review covers a selection of evidence from standardized population surveys, official statistics, and governmental reports, as well as published articles and books identified via MEDLINE, Web of Science, and Google Scholar as of July 2016. Results In relation to quantity, an estimated 3% to 5% of the world population is thought to have tried a cannabis product, with at least one fairly recent use, mainly extra-medical and outside boundaries of prescribed use. Among cannabis users in the United States, roughly one in 7–8 has engaged in medical marijuana use. In relation to location, prevalence proportions reveal important variations across countries and between subgroups within countries. Regarding causes and mechanisms of starting to use cannabis, there is no compelling integrative and replicable conceptual model or theoretical formulation. Most studies of mechanisms have focused upon a ‘gateway sequence’ and person-to-person diffusion, with some recent work on disability-adjusted life years. A brief review of cannabis use consequences, as well as prevention and control strategies is also provided. Conclusion At present, we know much about the frequency and occurrence of cannabis use, with too little replicable definitive evidence with respect to the other main rubrics. Given a changing regulatory environment for cannabis products, new institutions such as an independent International Cannabis Products Safety Commission may be required to produce evidence required to weigh benefits versus costs. It is not clear that government sponsored research will be sufficient to meet consumer demand for balanced points of view and truly definitive evidence
Ruchlemer, Rosa; Amit-Kohn, Michal; Raveh, David; Hanuš, Lumír
Medicinal cannabis is an invaluable adjunct therapy for pain relief, nausea, anorexia, and mood modification in cancer patients and is available as cookies or cakes, as sublingual drops, as a vaporized mist, or for smoking. However, as with every herb, various microorganisms are carried on its leaves and flowers which when inhaled could expose the user, in particular immunocompromised patients, to the risk of opportunistic lung infections, primarily from inhaled molds. The objective of this study was to identify the safest way of using medicinal cannabis in immunosuppressed patients by finding the optimal method of sterilization with minimal loss of activity of cannabis. We describe the results of culturing the cannabis herb, three methods of sterilization, and the measured loss of a main cannabinoid compound activity. Systematic sterilization of medicinal cannabis can eliminate the risk of fatal opportunistic infections associated with cannabis among patients at risk.
Buckner, Julia D.; Crosby, Ross D.; Wonderlich, Stephen A.; Schmidt, Norman B.
Individuals with elevated social anxiety appear especially vulnerable to cannabis-related problems, yet little is known about the antecedents of cannabis-related behaviors among this high-risk population. The present study used ecological momentary assessment (EMA) to examine the relations among social anxiety, cannabis craving, state anxiety, situational variables, and cannabis use in the natural environment during ad-lib cannabis use episodes. Participants were 49 current cannabis users. During the two-week EMA period, social anxiety significantly interacted with cannabis craving to predict cannabis use both cross-sectionally and prospectively. Specifically, individuals with higher social anxiety and craving were most likely to use cannabis. There was a significant social anxiety X state anxiety X others’ use interaction such that when others were using cannabis, those with elevations in both trait social anxiety and state anxiety were the most likely to use cannabis. PMID:22246109
Taylor, Michelle; Collin, Simon M; Munafò, Marcus R; MacLeod, John; Hickman, Matthew; Heron, Jon
Evidence on the role of cannabis as a gateway drug is inconsistent. We characterise patterns of cannabis use among UK teenagers aged 13-18 years, and assess their influence on problematic substance use at age 21 years. We used longitudinal latent class analysis to derive trajectories of cannabis use from self-report measures in a UK birth cohort. We investigated (1) factors associated with latent class membership and (2) whether latent class membership predicted subsequent nicotine dependence, harmful alcohol use and recent use of other illicit drugs at age 21 years. 5315 adolescents had three or more measures of cannabis use from age 13 to 18 years. Cannabis use patterns were captured as four latent classes corresponding to 'non-users' (80.1%), 'late-onset occasional' (14.2%), 'early-onset occasional' (2.3%) and 'regular' users (3.4%). Sex, mother's substance use, and child's tobacco use, alcohol consumption and conduct problems were strongly associated with cannabis use. At age 21 years, compared with the non-user class, late-onset occasional, early-onset occasional and regular cannabis user classes had higher odds of nicotine dependence (OR=3.5, 95% CI 0.7 to 17.9; OR=12.1, 95% CI 1.0 to 150.3; and OR=37.2, 95% CI 9.5 to 144.8, respectively); harmful alcohol consumption (OR=2.6, 95% CI 1.5 to 4.3; OR=5.0, 95% CI 2.1 to 12.1; and OR=2.6, 95% CI 1.0 to 7.1, respectively); and other illicit drug use (OR=22.7, 95% CI 11.3 to 45.7; OR=15.9, 95% CI 3.9 to 64.4; and OR=47.9, 95% CI 47.9 to 337.0, respectively). One-fifth of the adolescents in our sample followed a pattern of occasional or regular cannabis use, and these young people were more likely to progress to harmful substance use behaviours in early adulthood. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.
Monshouwer, Karin; Van Laar, Margriet; Vollebergh, Wilma A
The key objective of Dutch cannabis policy is to prevent and limit the risks of cannabis consumption for users, their direct environment and society ('harm reduction'). This paper will focus on the tolerated sale of cannabis in 'coffee shops'. We give a brief overview of Dutch policy on coffee shops, its history and recent developments. Furthermore, we present epidemiological data that may be indicative of the effects of the coffee shop policy on cannabis and other drug use. Dutch coffee shop policy has become more restrictive in recent years and the number of coffee shops has decreased. Cannabis prevalence rates in the adult population are somewhat below the European average; the rate is relatively high among adolescents; and age of first use appears to be low. On a European level, the use of hard drugs in both the Dutch adult and adolescent population is average to low (except for ecstasy among adults). International comparisons do not suggest a strong, upward effect of the coffee shop system on levels of cannabis use, although prevalence rates among Dutch adolescents give rise to concern. Furthermore, the coffee shop system appears to be successful in separating the hard and soft drugs markets. Nevertheless, in recent years, issues concerning the involvement of organised crime and the public nuisance related to drug tourism have given rise to several restrictive measures on the local level and have sparked a political debate on the reform of Dutch drug policy. © 2011 Trimbos Institute.
Jawad, Mohammed; Bakir, Ali; Ali, Mohammed; Grant, Aimee
Despite the rise in prevalence of waterpipe tobacco smoking, it has received little legislative enforcement from governing bodies, especially in the area of health warning labels. Twenty regular waterpipe tobacco smokers from London took part in five focus groups discussing the impact of waterpipe tobacco pack health warnings on their attitudes towards waterpipe smoking. We presented them with existing and mock waterpipe tobacco products, designed to be compliant with current and future UK/EU legislation. Data were analysed using thematic analysis. Participants felt packs were less attractive and health warnings were more impactful as health warnings increased in size and packaging became less branded. However, participants highlighted their lack of exposure to waterpipe tobacco pack health warnings due to the inherent nature of waterpipe smoking, that is, smoking in a café with the apparatus already prepacked by staff. Health warnings at the point of consumption had more reported impact than health warnings at the point of sale. Waterpipe tobacco pack health warnings are likely to be effective if compliant with existing laws and exposed to end-users. Legislations should be reviewed to extend health warning labels to waterpipe accessories, particularly the apparatus, and to waterpipe-serving premises.
Primack, Brian A; Douglas, Erika L; Kraemer, Kevin L
Cannabis use is referenced frequently in American popular music, yet it remains uncertain whether exposure to these references is associated with actual cannabis use. We aimed to determine if exposure to cannabis in popular music is associated independently with current cannabis use in a cohort of urban adolescents. We surveyed all 9th grade students at three large US urban high schools. We estimated participants' exposure to lyrics referent to cannabis with overall music exposure and content analyses of their favorite artists' songs. Outcomes included current (past 30 days) and ever use of cannabis. We used multivariable regression to assess independent associations between exposures and outcomes while controlling for important covariates. Each of the 959 participants was exposed to an estimated 27 cannabis references per day [correction added on 19 January 2010, after first online publication: 40 has been changed to 27] (standard deviation = 73 [correction added on 19 January 2010, after first online publication: 104 has been changed to 73]). Twelve per cent (n = 108) were current cannabis users and 32% (n = 286) had ever used cannabis. Compared with those in the lowest tertile of total cannabis exposure in music, those in the highest tertile of exposure were almost twice as likely to have used cannabis in the past 30 days (odds ratio = 1.83; 95% confidence interval = 1.04, 3.22), even after adjusting for socio-demographic variables, personality characteristics and parenting style. As expected, however, there was no significant relationship between our cannabis exposure variable and a sham outcome variable of alcohol use. This study supports an independent association between exposure to cannabis in popular music and early cannabis use among urban American adolescents.
Cowan, Ronald L; Joers, James M; Dietrich, Mary S
Impaired verbal memory is common in MDMA (Ecstasy) polydrug users. The contributions of Ecstasy or polydrug exposure to reduced verbal memory are unclear, as is the neural basis for this cognitive deficit. Ecstasy users have reduced gray matter in brain regions mediating verbal memory (BA 18, 21 and 45). N-acetylaspartate (NAA) as a neuronal marker and myoinositol (mI) as a glial marker are inconsistently affected in Ecstasy users. We used 3 T MRS in 17 recreational drug users to test the hypothesis that Ecstasy polydrug use would be associated with altered NAA or mI in BA 18, 21 and 45. No effects were seen for mI. Metabolite ratios for NAA (mean+/-SD) were: BA 18-NAA/Cr (2.030+/-0.188); BA 21-NAA/Cr (1.861+/-0.325); BA 45-NAA/Cr (1.925+/-0.329). Lifetime cannabis use was significantly associated with BA 45 NAA/Cr (r=-0.687, p=0.014) but not with NAA in BA 18 or 21. In contrast, there were no statistically significant associations for lifetime use of Ecstasy, alcohol, or cocaine with NAA. These findings suggest that cannabis use may contribute to altered neuronal integrity in Ecstasy polydrug users in a brain region associated with verbal memory processing.
Cowan, Ronald L; Joers, James M; Dietrich, Mary S
Impaired verbal memory is common in MDMA (Ecstasy) polydrug users. The contributions of Ecstasy or polydrug exposure to reduced verbal memory are unclear, as is the neural basis for this cognitive deficit. Ecstasy users have reduced gray matter in brain regions mediating verbal memory (BA 18, 21 and 45). N-acetylaspartate (NAA) as a neuronal marker and myoinositol (mI) as a glial marker are inconsistently affected in Ecstasy users. We used 3 Tesla MRS in 17 recreational drug users to test the hypothesis that Ecstasy polydrug use would be associated with altered NAA or mI in BA 18, 21 and 45. No effects were seen for mI. Metabolite ratios for NAA (mean ± SD) were: BA 18--NAA/Cr (2.030 ± 0.188); BA 21--NAA/Cr (1.861 ± 0.325); BA 45--NAA/Cr (1.925 ± 0.329). Lifetime cannabis use was significantly associated with BA 45 NAA/Cr (r = −0.687, p = 0.014) but not with NAA in BA 18 or 21. In contrast, there were no statistically significant associations for lifetime use of Ecstasy, alcohol, or cocaine with NAA. These findings suggest that cannabis use may contribute to altered neuronal integrity in Ecstasy polydrug users in a brain region associated with verbal memory processing. PMID:19032963
Sampasa-Kanyinga, Hugues; Hamilton, Hayley A.; LeBlanc, Allana G.; Chaput, Jean-Philippe
Background: Cannabis use can have serious detrimental effects in children and adolescents. It is therefore important to continually assess the use of cannabis among young people in order to inform prevention efforts. We assessed the prevalence of cannabis use among middle and high school students in Ontario and examined its association with demographic and behavioural factors. Methods: Data were obtained from the 2015 Ontario Student Drug Use and Health Survey, a province-wide school-based survey of students in grades 7 through 12. Analyses included a representative sample of 9920 middle and high school students. Bivariate cross-tabulations and logistic regression analyses were used to investigate the factors associated with cannabis use. Results: Overall, 21.5% and 13.9% of students reported using cannabis in the previous year and previous month, respectively. The conditional probability that an adolescent who reported cannabis use in the previous year would report daily use was 12.5%. There was a significant dose-response gradient with age, with older students being more likely to use cannabis than younger students. In multivariable analyses, being in grades 10 through 12 (odds ratios [ORs] ranged from 3.71 to 3.85), being black (OR 2.67 [95% confidence interval (CI) 1.76-4.05]), using tobacco cigarettes (OR 10.10 [95% CI 8.68-13.92]) and being an occasional (OR 5.35 [95% CI 4.01-7.13]) or regular (OR 14.6 [95% CI 10.8-19.89]) alcohol user were associated with greater odds of cannabis use. Being an immigrant was associated with lower odds of cannabis use (OR 0.55 [95% CI 0.39-0.78]). Interpretation: The findings suggest that cannabis use is prevalent among middle and high school students in Ontario and is strongly associated with tobacco cigarette smoking and alcohol consumption. Future research should document trends in cannabis use over time, including its risks, especially when the legalization of recreational cannabis comes into effect. PMID:29367264
Background General practitioners (GPs) and nurses are ideally placed to address the significant unmet demand for the treatment of cannabis-related problems given the numbers of people who regularly seek their care. The aim of this study was to evaluate differences between GPs and nurses’ perceived knowledge, beliefs, and behaviors toward cannabis use and its screening and management. Methods This study involved 161 nurses and 503 GPs who completed a survey distributed via conference satchels to delegates of Healthed seminars focused on topics relevant to women and children’s health. Differences between GPs and nurses were analyzed using χ2- tests and two-sample t-tests, while logistic regression examined predictors of service provision. Results GPs were more likely than nurses to have engaged in cannabis-related service provision, but also more frequently reported barriers related to time, interest, and having more important issues to address. Nurses reported less knowledge, skills, and role legitimacy. Perceived screening skills predicted screening and referral to alcohol and other drug (AOD) services, while knowing a regular user increased the likelihood of referrals only. Conclusions Approaches to increase cannabis-related screening and intervention may be improved by involving nurses, and by leveraging the relationship between nurses and doctors, in primary care. PMID:22827931
Norberg Melissa M
Full Text Available Abstract Background General practitioners (GPs and nurses are ideally placed to address the significant unmet demand for the treatment of cannabis-related problems given the numbers of people who regularly seek their care. The aim of this study was to evaluate differences between GPs and nurses’ perceived knowledge, beliefs, and behaviors toward cannabis use and its screening and management. Methods This study involved 161 nurses and 503 GPs who completed a survey distributed via conference satchels to delegates of Healthed seminars focused on topics relevant to women and children’s health. Differences between GPs and nurses were analyzed using χ2- tests and two-sample t-tests, while logistic regression examined predictors of service provision. Results GPs were more likely than nurses to have engaged in cannabis-related service provision, but also more frequently reported barriers related to time, interest, and having more important issues to address. Nurses reported less knowledge, skills, and role legitimacy. Perceived screening skills predicted screening and referral to alcohol and other drug (AOD services, while knowing a regular user increased the likelihood of referrals only. Conclusions Approaches to increase cannabis-related screening and intervention may be improved by involving nurses, and by leveraging the relationship between nurses and doctors, in primary care.
Norberg, Melissa M; Gates, Peter; Dillon, Paul; Kavanagh, David J; Manocha, Ramesh; Copeland, Jan
General practitioners (GPs) and nurses are ideally placed to address the significant unmet demand for the treatment of cannabis-related problems given the numbers of people who regularly seek their care. The aim of this study was to evaluate differences between GPs and nurses' perceived knowledge, beliefs, and behaviors toward cannabis use and its screening and management. This study involved 161 nurses and 503 GPs who completed a survey distributed via conference satchels to delegates of Healthed seminars focused on topics relevant to women and children's health. Differences between GPs and nurses were analyzed using χ(2)- tests and two-sample t-tests, while logistic regression examined predictors of service provision. GPs were more likely than nurses to have engaged in cannabis-related service provision, but also more frequently reported barriers related to time, interest, and having more important issues to address. Nurses reported less knowledge, skills, and role legitimacy. Perceived screening skills predicted screening and referral to alcohol and other drug (AOD) services, while knowing a regular user increased the likelihood of referrals only. Approaches to increase cannabis-related screening and intervention may be improved by involving nurses, and by leveraging the relationship between nurses and doctors, in primary care.
Weinstein, Aviv; Brickner, Orit; Lerman, Hedva; Greemland, Mazal; Bloch, Miki; Lester, Hava; Chisin, Roland; Mechoulam, Raphael; Bar-Hamburger, Rachel; Freedman, Nanette; Even-Sapir, Einat
Twelve regular users of marijuana underwent two positron emission tomography (PET) scans using [18F] Fluorodeoxyglucose (FDG), one while subject to the effects of 17 mg THC, the other without THC. In both sessions, a virtual reality maze task was performed during the FDG uptake period. When subject to the effects of 17 mg THC, regular marijuana smokers hit the walls more often on the virtual maze task than without THC. Compared to results without THC, 17 mg THC increased brain metabolism during task performance in areas that are associated with motor coordination and attention in the middle and medial frontal cortices and anterior cingulate, and reduced metabolism in areas that are related to visual integration of motion in the occipital lobes. These findings suggest that in regular marijuana users, the immediate effects of marijuana may impact on cognitive-motor skills and brain mechanisms that modulate coordinated movement and driving.
Zamengo, Luca; Frison, Giampietro; Bettin, Chiara; Sciarrone, Rocco
Cannabis is the most widely used illicit substance globally, with an estimated annual prevalence in 2010 of 2.6-5.0% of the adult population. Concerns have been expressed about increases in the potency of cannabis products. A high tetrahydrocannabinol (THC) content can increase anxiety, depression, and psychotic symptoms, and can increase the risk of dependence and adverse effects on the respiratory and cardiovascular systems in regular users. The aim of this study was to report statistical data about the potency of cannabis products seized in the north-east of Italy, in a geographical area centred in Venice and extending for more than 10,000 km(2) with a population of more than two million, by investigating the variability observed in THC levels of about 4000 samples of cannabis products analyzed over the period 2010-2012. Overall median THC content showed an increasing trend over the study period from about 6.0% to 8.1% (6.2-8.9% for cannabis resin, 5.1-7.6% for herbal cannabis). The variation in the THC content of individual samples was very large, ranging from 0.3% to 31% for cannabis resin and from 0.1 to 19% for herbal cannabis. Median CBN:THC ratios showed a slightly decreasing trend over the study period, from 0.09 (2010) to 0.03 (2012), suggesting an increasing freshness of submitted materials. Median CBD:THC ratios also showed a decreasing trend over the study from about 0.52 (2010) to 0.18 (2012), likely due to the increase in submissions of materials from indoor and domestic cultivation with improved breeding methods. Copyright © 2013 John Wiley & Sons, Ltd.
Jager, Gerry; van Hell, Hendrika H.; de Win, Maartje M. L.; Kahn, Rene S.; van den Brink, Wim; van Ree, Jan M.; Ramsey, Nick F.
Interest is growing in the neurotoxic potential of cannabis on human brain function. We studied non-acute effects of frequent cannabis use on hippocampus-dependent associative memory, investigated with functional Magnetic Resonance Imaging (fMRI) in 20 frequent cannabis users and 20 non-users
Jonathan K Burns
Full Text Available The nature of the relationship between cannabis use and psychosis is complex and remains unclear. Researchers and clinicians remain divided regarding key issues such as whether or not cannabis is an independent cause of psychosis and schizophrenia. This paper reviews the field in detail, examining questions of causality, the neurobiological basis for such causality and for differential inter-individual risk, the clinical and cognitive features of psychosis in cannabis users, and patterns of course and outcome of psychosis in the context of cannabis use. The author proposes two major pathways from cannabis to psychosis based on a differentiation between early-initiated lifelong cannabis use and a scenario where vulnerable individuals without a lifelong pattern of use consume cannabis over a relatively brief period of time just prior to psychosis onset. Additional key factors determining the clinical and neurobiological manifestation of psychosis as well as course and outcome in cannabis users include: underlying genetic and developmental vulnerability to schizophrenia-spectrum disorders; and whether or not cannabis use ceases or continues after the onset of psychosis. Finally, methodological guidelines are presented for future research aimed at both elucidating the pathways that lead from cannabis to psychosis and clarifying the long-term outcome of the disorder in those who have a history of using cannabis.
A number of therapeutic uses of cannabis and its derivatives have been postulated from preclinical investigations. Possible clinical indications include spasticity and pain in multiple sclerosis, cancer-associated nausea and vomiting, cancer pain and HIV neuropathy. However, evidence is limited, may reflect subjective rather than objective outcomes, and is not conclusive. Controversies lie in how to produce, supply and administer cannabinoid products. Introduction of cannabinoids therapeutically should be supported by a regulatory and educational framework that minimises the risk of harm to patients and the community. The Regulator of Medicinal Cannabis Bill 2014 is under consideration in Australia to address this. Nabiximols is the only cannabinoid on the Australian Register of Therapeutic Goods at present, although cannabidiol has been recommended for inclusion in Schedule 4.
Gilman, Jodi M; Lee, Sang; Kuster, John K; Lee, Myung Joo; Kim, Byoung Woo; van der Kouwe, Andre; Blood, Anne J; Breiter, Hans C
Decades of research have demonstrated the importance of social influence in initiation and maintenance of drug use, but little is known about neural mechanisms underlying social influence in young adults who use recreational drugs. To better understand whether the neural and/or behavioral response to social influence differs in young adults using illicit drugs, 20 marijuana-using young adults (MJ) aged 18-25, and 20 controls (CON) performed a decision-making task in the context of social influence, while they underwent functional magnetic resonance imaging scans. A priori analyses focused on the nucleus accumbens (NAc), with post hoc analyses in the rest of the striatum. In this task, participants could choose to either follow or go against group influence. When subjects applied social information to response choice selection (independent of following or going against group influence), we observed activation in the middle striatum (caudate), in the MJ group only, that extended ventrally into the NAc. MJ users but not CON showed greater activation in the NAc but not the caudate while making choices congruent with group influence as opposed to choices going against group influence. Activation in the NAc when following social influence was associated with amount of drug use reported. In contrast, during the feedback phase of the task we observed significant NAc activation in both MJ and CON, along with dorsal caudate activation only in MJ participants. This NAc activation did not correlate with drug use. This study shows that MJ users, but not CON, show differential brain activation across striatal subregions when applying social information to make a decision, following versus going against a group of peers, or receiving positive feedback. The current work suggests that differential neural sensitivity to social influence in regions such as the striatum may contribute to the development and/or maintenance of marijuana use.
Kronbæk, Mette; Frank, Vibeke Asmussen
AIM - To discuss similarities and differences in the way cannabis users with and without treatment experiences present their trajectories into daily use of cannabis. To observe the differences in patterns between the cannabis users’ descriptions of their recreational use and the development from...... a recreational to a more problematic use of cannabis. METHODS - Qualitative interviews were conducted with 32 adult cannabis users in Denmark. All respondents used cannabis daily. The respondents were 22-61 years old; 16 had had experiences with cannabis treatment while 16 had not. By using a mixed sample...... of respondents with and without treatment experiences, we were able to compare perspectives on cannabis initiation and trajectories not commonly examined. FINDINGS - All the respondents had started to use cannabis socially as adolescents in the company of peers, using it with specific peer groups...
The purpose of this thesis work was to investigate and analyze in what way online adver-tising in Twitter affects its regular users nowadays. More specifically it focused on the young (20-30 years old) frequent Internet users of the social networking medium. The theoretical part of the study introduced Twitter and methods of advertising in it. The em-pirical part of the thesis was conducted by using a quantitative research method. The data was gathered from discussions of a focus and a contro...
Full Text Available The present study was conducted in order to quantify to what extent cannabis consumers may be exposed to pesticide and other chemical residues through inhaled mainstream cannabis smoke. Three different smoking devices were evaluated in order to provide a generalized data set representative of pesticide exposures possible for medical cannabis users. Three different pesticides, bifenthrin, diazinon, and permethrin, along with the plant growth regulator paclobutrazol, which are readily available to cultivators in commercial products, were investigated in the experiment. Smoke generated from the smoking devices was condensed in tandem chilled gas traps and analyzed with gas chromatography-mass spectrometry (GC-MS. Recoveries of residues were as high as 69.5% depending on the device used and the component investigated, suggesting that the potential of pesticide and chemical residue exposures to cannabis users is substantial and may pose a significant toxicological threat in the absence of adequate regulatory frameworks.
Van Laar, Margriet; Van Der Pol, Peggy; Niesink, Raymond
The Netherlands has seen an increase in Δ9-tetrahydrocannabinol (THC) concentrations from approximately 8% in the 1990s up to 20% in 2004. Increased cannabis potency may lead to higher THC-exposure and cannabis related harm. The Dutch government officially condones the sale of cannabis from so called 'coffee shops', and the Opium Act distinguishes cannabis as a Schedule II drug with 'acceptable risk' from other drugs with 'unacceptable risk' (Schedule I). Even in 1976, however, cannabis potency was taken into account by distinguishing hemp oil as a Schedule I drug. In 2011, an advisory committee recommended tightening up legislation, leading to a 2013 bill proposing the reclassification of high potency cannabis products with a THC content of 15% or more as a Schedule I drug. The purpose of this measure was twofold: to reduce public health risks and to reduce illegal cultivation and export of cannabis by increasing punishment. This paper focuses on the public health aspects and describes the (explicit and implicit) assumptions underlying this '15% THC measure', as well as to what extent these are supported by scientific research. Based on scientific literature and other sources of information, we conclude that the 15% measure can provide in theory a slight health benefit for specific groups of cannabis users (i.e., frequent users preferring strong cannabis, purchasing from coffee shops, using 'steady quantities' and not changing their smoking behaviour), but certainly not for all cannabis users. These gains should be weighed against the investment in enforcement and the risk of unintended (adverse) effects. Given the many assumptions and uncertainty about the nature and extent of the expected buying and smoking behaviour changes, the measure is a political choice and based on thin evidence. Copyright © 2016 Springer. Published by Elsevier B.V. All rights reserved.
Reddy, D C; Singh, S P; Tiwari, I C; Shukla, K P; Srivastava, M K
A study of 4326 students, selected by stratified random sampling and using a self administered questionnaire, revealed that overall cannabis abuse among them was 4.5%. It amounted to a considerable decline in prevalence compared to 10.2% observed in 1976. However, it was noted that this reduction was mainly in occasional users and the proportion of regular users has actually increased in 1986. The prevalence has also shown an increase among girl students. The regular users were mainly from professional colleges, hailing from metropolitan cities and with relatively higher amount of pocket money at their disposal. It was concluded that the observed trends could be due to peer pressures. It was also considered that health education of such students at entry point may help reduce the problem.
Jones, Connor B; Hill, Melanie L; Pardini, Dustin A; Meier, Madeline H
Vaping nicotine (i.e., the use of e-cigarettes and similar devices to inhale nicotine) is becoming increasingly popular among young people. Though some vaporizers are capable of vaporizing cannabis, sparse research has investigated this method of cannabis administration. The present study examines the prevalence and correlates of vaping cannabis in a sample of 482 college students. Participants reported high lifetime rates of vaping nicotine (37%) and cannabis (29%). Men (r s = 0.09, p = .047) and individuals from higher socioeconomic status families (r s = 0.14, p = .003) vaped cannabis more frequently than women and individuals from lower SES families. In addition, those who vaped cannabis more frequently were more open to new experiences (r s = 0.17, p vaping were frequent cannabis use (r s = 0.70, p vaping (r s = 0.46, p vaping cannabis, endorsed by 65% of those who had vaped cannabis, was convenience and discreetness for use in public places. Several correlates distinguished cannabis users who vaped from cannabis users who did not vape, most notably more frequent cannabis use (odds ratios [OR] = 3.68, p vaping (OR = 1.73, p vaping is prevalent among young adults, particularly among those who use other substances frequently and have more favorable attitudes toward smoking cannabis. Research is needed on the antecedents and potential harms and benefits of cannabis vaping in young adulthood. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Verweij, K.J.H.; Agrawal, A.; Nat, N.O.; Creemers, H.E.; Huizink, A.C.; Martin, N.G.; Lynskey, M.T.
Background Various studies support the inclusion of cannabis withdrawal to the diagnosis of cannabis use disorders in the upcoming DSM-5. The aims of the current study were to (1) estimate the prevalence of DSM-5 cannabis withdrawal (Criterion B), (2) estimate the role of genetic and environmental influences on individual differences in cannabis withdrawal, and (3) determine the extent to which genetic and environmental influences on cannabis withdrawal overlap with those on DSM-IV defined abuse/dependence. Methods The sample included 2276 lifetime cannabis-using adult Australian twins. Cannabis withdrawal was defined in accordance with Criterion B of the proposed DSM-5 revisions. Cannabis abuse/dependence was defined as endorsing one or more DSM-IV criteria of abuse or three or more dependence criteria. The classical twin model was used to estimate the genetic and environmental influences on variation in cannabis withdrawal, as well as its covariation with abuse/dependence. Results Of all cannabis users 11.9% met criteria for cannabis withdrawal. Around 50% of between-individual variation in withdrawal could be attributed to additive genetic variation, and the rest of the variation was mostly due to non-shared environmental influences. Importantly, the genetic influences on cannabis withdrawal almost completely (99%) overlapped with those on abuse/dependence. Conclusions We showed that cannabis withdrawal symptoms exist among cannabis users, and that cannabis withdrawal is moderately heritable. Genetic influences on cannabis withdrawal are the same as those influencing abuse/dependence. These results add to the wealth of literature that recommends the addition of cannabis withdrawal to the diagnosis of DSM-5 cannabis use disorders. PMID:23194657
Dierker, Lisa; Braymiller, Jessica; Rose, Jennifer; Goodwin, Renee; Selya, Arielle
We evaluate if cigarette smoking and/or nicotine dependence predicts cannabis use disorder symptoms among adolescent and young adult cannabis users and whether the relationships differ based on frequency of cannabis use. Data were drawn from seven annual surveys of the NSDUH to include adolescents and young adults (age 12-21) who reported using cannabis at least once in the past 30 days (n = 21,928). Cannabis use frequency trends in the association between cigarette smoking, nicotine dependence and cannabis use disorder symptoms were assessed using Varying Coefficient Models (VCM's). Over half of current cannabis users also smoked cigarettes in the past 30 days (54.7% SE 0.48). Cigarette smoking in the past 30 days was associated with earlier onset of cannabis use, more frequent cannabis use and a larger number of cannabis use disorder symptoms compared to those who did not smoke cigarettes. After statistical control for socio-demographic characteristics and other substance use behaviors, nicotine dependence but not cigarette smoking quantity or frequency was positively and significantly associated with each of the cannabis use disorder symptoms as well as the total number of cannabis symptoms endorsed. Higher nicotine dependence scores were consistently associated with the cannabis use disorder symptoms across all levels of cannabis use from 1 day used (past month) to daily cannabis use, though the relationship was strongest among infrequent cannabis users. Prevention and treatment efforts should consider cigarette smoking comorbidity when addressing the increasing proportion of the US population that uses cannabis. Copyright © 2018 Elsevier B.V. All rights reserved.
Wouters, M.; Benschop, A.; van Laar, M.; Korf, D.J.
The aim of this paper is to assess the influence of coffee shop availability on the prevalence and intensity of cannabis use, as well as the effectiveness of the ‘separation of markets’ policy. A convenience sample of nightlife visitors and a sub-selection of previous year cannabis users were used
Full Text Available Tabea Schoeler, Sagnik BhattacharyyaDepartment of Psychosis Studies, King's College London, Institute of Psychiatry, London, UKAbstract: Investigating the effects of cannabis use on memory function appears challenging. While early observational investigations aimed to elucidate the longer-term effects of cannabis use on memory function in humans, findings remained equivocal and pointed to a pattern of interacting factors impacting on the relationship between cannabis use and memory function, rather than a simple direct effect of cannabis. Only recently, a clearer picture of the chronic and acute effects of cannabis use on memory function has emerged once studies have controlled for potential confounding factors and started to investigate the acute effects of delta-9-tetrahydrocannabinol (Δ9-THC and cannabidiol (CBD, the main ingredients in the extract of the cannabis plant in pharmacological challenge experiments. Relatively consistent findings have been reported regarding the acute impairments induced by a single dose of Δ9-THC on verbal and working memory. It is unclear whether they may persist beyond the intoxication state. In the long-term, these impairments seem particularly likely to manifest and may also persist following abstinence if regular and heavy use of cannabis strains high in Δ9-THC is started at an early age. Although still at an early stage, studies that employed advanced neuroimaging techniques have started to model the neural underpinnings of the effects of cannabis use and implicate a network of functional and morphological alterations that may moderate the effects of cannabis on memory function. Future experimental and epidemiological studies that take into consideration individual differences, particularly previous cannabis history and demographic characteristics, but also the precise mixture of the ingredients of the consumed cannabis are necessary to clarify the magnitude and the mechanisms by which cannabis
Alfredo Jácome Roca
Full Text Available Los estupefacientes han estado presentes en la historia de la medicina desde la antigüedad. La materia médica china (Pen-ts’ao-Ching atribuida al emperador rojo Shen-nung, incluye a la Cannabis indica para reducir el dolor del reumatismo y por sus beneficios en desórdenes digestivos. El láudano (tintura alcohólica de opio, la esponja anestésica (mandrágora con opio, o la teriaca (polifármaco que contenía opio fueron pilar de la lucha contra el dolor y otros males. El opio proviene del jugo de la corteza verde de la adormidera –variedad de amapola- o Papaver somniferum y ha sido reemplazado como potente analgésico de acción central por su alcaloide morfina o por análogos como la meperidina (1. Desde sus orígenes, el ser humano ha buscado alivio en diversas plantas medicinales, la analgesia, la sedación pero también la euforia. El efecto pasajero y la taquifilaxia generada por el uso continuo impulsan un aumento en la frecuencia y en la cantidad de las dosis, perdiéndose sus beneficios y aumentando su toxicidad. En estos casos, disminuye el número y la sensibilidad de los diferentes receptores, fenómeno conocido como down-regulation. Al ser adictivos, el manejo de estos narcóticos debe ser estrictamente médico y fuertemente regulado, cosa de la que se han librado el alcohol y el tabaco. La prohibición del licor solo llevó al enriquecimiento de los contrabandistas. Hay alucinógenos menos villanos como los obtenidos de la Cannabis sativa, aunque no son demasiado benignos.
van der Pol, P.; Liebregts, N.; Brunt, T.; van Amsterdam, J.; de Graaf, R.; Korf, D.J.; van den Brink, W.; van Laar, M.
Background and Aims Increased delta-9-tetrahydrocannabinol (THC) concentrations in cannabis may lead to higher THC exposure, cannabis dependence and treatment need, but users may also adapt the actual intake of THC through reduced inhalation of THC containing smoke (titration). We investigated
van der Pol, Peggy; Liebregts, Nienke; Brunt, Tibor; van Amsterdam, Jan; de Graaf, Ron; Korf, Dirk J.; van den Brink, Wim; van Laar, Margriet
Increased delta-9-tetrahydrocannabinol (THC) concentrations in cannabis may lead to higher THC exposure, cannabis dependence and treatment need, but users may also adapt the actual intake of THC through reduced inhalation of THC containing smoke (titration). We investigated whether consumers of
Cannabis saliva ('dagga') affects the central nervous system. (CNS) in a variety of ... to cannabis use. These include delusional thinking, paranoid ideas ... It is thought to consist of diminished drive, volition and ambition, a loss of motivation,.
Mark A Ware
Full Text Available Safety issues are a major barrier to the use of cannabis and cannabinoid medications for clinical purposes. Information on the safety of herbal cannabis may be derived from studies of recreational cannabis use, but cannabis exposure and effects may differ widely between medical and recreational cannabis users. Standardized, quality-controlled cannabinoid products are available in Canada, and safety profiles of approved medications are available through the Canadian formulary. In the present article, the evidence behind major safety issues related to cannabis use is summarized, with the aim of promoting informed dialogue between physicians and patients in whom cannabinoid therapy is being considered. Caution is advised in interpreting these data, because clinical experience with cannabinoid use is in the early stages. There is a need for long-term safety monitoring of patients using cannabinoids for a wide variety of conditions, to further guide therapeutic decisions and public policy.
Dahl, Silje Louise; Demant, Jakob Johan
investigate how cannabis users from 23–40 years discuss their use and act to present themselves as adult smokers. The analysis is based on semistructured interviews with 25 experienced cannabis users. Findings: When cannabis users continue smoking in adulthood, they must negotiate their self......-presentations within a discourse of adultness where maturing out of illegal drug use is expected. The participants presented themselves as adults by using three strategies: negotiating playfulness and obligations, mature narration of cannabis use and mature ways of administering cannabis. Conclusions: By continuing...... to smoke in adulthood, they challenge the notion that cannabis use is linked to youth. Simultaneously, they moderate their use to meet expectations of adultness, thus reproducing the idea that cannabis use belongs to the youth phase. When the participants project a mature lifestyle by under...
Garry, Aurélia; Rigourd, Virginie; Amirouche, Ammar; Fauroux, Valérie; Aubry, Sylvie; Serreau, Raphaël
Cannabis is a drug derived from hemp plant, Cannabis sativa, used both as a recreational drug or as medicine. It is a widespread illegal substance, generally smoked for its hallucinogenic properties. Little is known about the adverse effects of postnatal cannabis exposure throw breastfeeding because of a lack of studies in lactating women. The active substance of cannabis is the delta 9 TetraHydroCannabinol (THC). Some studies conclude that it could decrease motor development of the child at ...
Buckner, Julia D; Zvolensky, Michael J; Ecker, Anthony H
There is little research that has sought to identify factors related to quit success and failure among cannabis users. The current study examined affective, cognitive, and situational factors related to cannabis use among current cannabis users undergoing a voluntary, self-guided quit attempt. The sample consisted of 30 (33% female) current cannabis users, 84% of whom evinced a current cannabis use disorder. Ecological momentary assessment was used to collect multiple daily ratings of cannabis withdrawal, negative affect, peer cannabis use, reasons for use, and successful coping strategies over two weeks. Findings from generalized linear models indicated that cannabis withdrawal and positive and negative affect were significantly higher during cannabis use than non-use episodes. Additionally, when negative and positive affect were entered simultaneously, negative affect, but not positive affect, remained significantly related to use. Participants were significantly more likely to use in social situations than when alone. When participants were in social situations, they were significantly more likely to use if others were using. Participants tended to use more behavioral than cognitive strategies to abstain from cannabis. The most common reason for use was to cope with negative affect. Overall, these novel findings indicate that cannabis withdrawal, affect (especially negative affect), and peer use play important roles in cannabis use among self-quitters. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Schmits, Emilie; Maurage, Pierre; Thirion, Romain; Quertemont, Etienne
Cannabis is one of the most commonly drugs used by teenagers. Expectancies about its effects play a crucial role in cannabis consumption. Various tools have been used to assess expectancies, mainly self-report questionnaires measuring explicit expectancies, but implicit measures based on experimental tasks have also been developed, measuring implicit expectancies. The aim of this study was to simultaneously assess implicit/explicit expectancies related to cannabis among adolescent users and non-users. 130 teenagers attending school (55 girls) were enrolled (Age: M=16.40 years); 43.84% had never used cannabis ("non-users") and 56.16% had used cannabis ("users"). They completed self-report questionnaires evaluating cannabis use, cannabis-related problems, effect expectancies (explicit expectancies), alcohol use, social and trait anxiety, depression, as well as three Implicit Association Tests (IAT) assessing implicit expectancies. Adolescents manifested more implicit affective associations (relaxation, excitation, negative) than neutral ones regarding cannabis. These were not related to explicit expectancies. Cannabis users reported more implicit relaxation expectancies and less negative explicit expectancies than non-users. The frequency of use and related problems were positively associated with the explicit expectancies regarding relaxation and enhancement, and were negatively associated with negative explicit expectancies and negative implicit expectancies. Findings indicate that implicit and explicit expectancies play different roles in cannabis use by adolescents. The implications for experimentation and prevention are discussed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Fiz, Jimena; Durán, Marta; Capellà, Dolors; Carbonell, Jordi; Farré, Magí
The aim of this study was to describe the patterns of cannabis use and the associated benefits reported by patients with fibromyalgia (FM) who were consumers of this drug. In addition, the quality of life of FM patients who consumed cannabis was compared with FM subjects who were not cannabis users. Information on medicinal cannabis use was recorded on a specific questionnaire as well as perceived benefits of cannabis on a range of symptoms using standard 100-mm visual analogue scales (VAS). Cannabis users and non-users completed the Fibromyalgia Impact Questionnaire (FIQ), the Pittsburgh Sleep Quality Index (PSQI) and the Short Form 36 Health Survey (SF-36). Twenty-eight FM patients who were cannabis users and 28 non-users were included in the study. Demographics and clinical variables were similar in both groups. Cannabis users referred different duration of drug consumption; the route of administration was smoking (54%), oral (46%) and combined (43%). The amount and frequency of cannabis use were also different among patients. After 2 hours of cannabis use, VAS scores showed a statistically significant (pcannabis users than in non-users. No significant differences were found in the other SF-36 domains, in the FIQ and the PSQI. The use of cannabis was associated with beneficial effects on some FM symptoms. Further studies on the usefulness of cannabinoids in FM patients as well as cannabinoid system involvement in the pathophysiology of this condition are warranted.
Li, Kong M.; Arnold, Jonathon C.; McGregor, Iain S.
Recent analysis of the cannabinoid content of cannabis plants suggests a shift towards use of high potency plant material with high levels of Δ9-tetrahydrocannabinol (THC) and low levels of other phytocannabinoids, particularly cannabidiol (CBD). Use of this type of cannabis is thought by some to predispose to greater adverse outcomes on mental health and fewer therapeutic benefits. Australia has one of the highest per capita rates of cannabis use in the world yet there has been no previous systematic analysis of the cannabis being used. In the present study we examined the cannabinoid content of 206 cannabis samples that had been confiscated by police from recreational users holding 15 g of cannabis or less, under the New South Wales “Cannabis Cautioning” scheme. A further 26 “Known Provenance” samples were analysed that had been seized by police from larger indoor or outdoor cultivation sites rather than from street level users. An HPLC method was used to determine the content of 9 cannabinoids: THC, CBD, cannabigerol (CBG), and their plant-based carboxylic acid precursors THC-A, CBD-A and CBG-A, as well as cannabichromene (CBC), cannabinol (CBN) and tetrahydrocannabivarin (THC-V). The “Cannabis Cautioning” samples showed high mean THC content (THC+THC-A = 14.88%) and low mean CBD content (CBD+CBD-A = 0.14%). A modest level of CBG was detected (CBG+CBG-A = 1.18%) and very low levels of CBC, CBN and THC-V (cannabis with very low CBD content. The implications for public health outcomes and harm reduction strategies are discussed. PMID:23894589
Full Text Available Recent analysis of the cannabinoid content of cannabis plants suggests a shift towards use of high potency plant material with high levels of Δ(9-tetrahydrocannabinol (THC and low levels of other phytocannabinoids, particularly cannabidiol (CBD. Use of this type of cannabis is thought by some to predispose to greater adverse outcomes on mental health and fewer therapeutic benefits. Australia has one of the highest per capita rates of cannabis use in the world yet there has been no previous systematic analysis of the cannabis being used. In the present study we examined the cannabinoid content of 206 cannabis samples that had been confiscated by police from recreational users holding 15 g of cannabis or less, under the New South Wales "Cannabis Cautioning" scheme. A further 26 "Known Provenance" samples were analysed that had been seized by police from larger indoor or outdoor cultivation sites rather than from street level users. An HPLC method was used to determine the content of 9 cannabinoids: THC, CBD, cannabigerol (CBG, and their plant-based carboxylic acid precursors THC-A, CBD-A and CBG-A, as well as cannabichromene (CBC, cannabinol (CBN and tetrahydrocannabivarin (THC-V. The "Cannabis Cautioning" samples showed high mean THC content (THC+THC-A = 14.88% and low mean CBD content (CBD+CBD-A = 0.14%. A modest level of CBG was detected (CBG+CBG-A = 1.18% and very low levels of CBC, CBN and THC-V (<0.1%. "Known Provenance" samples showed no significant differences in THC content between those seized from indoor versus outdoor cultivation sites. The present analysis echoes trends reported in other countries towards the use of high potency cannabis with very low CBD content. The implications for public health outcomes and harm reduction strategies are discussed.
Cerdá, Magdalena; Moffitt, Terrie E.; Meier, Madeline H.; Harrington, HonaLee; Houts, Renate; Ramrakha, Sandhya; Hogan, Sean; Poulton, Richie; Caspi, Avshalom
With the increasing legalization of cannabis, understanding the consequences of cannabis use is particularly timely. We examined the association between cannabis use and dependence, prospectively assessed between ages 18–38, and economic and social problems at age 38. We studied participants in the Dunedin Longitudinal Study, a cohort (n=1,037) followed from birth to age 38. Study members with regular cannabis use and persistent dependence experienced downward socioeconomic mobility, more financial difficulties, workplace problems, and relationship conflict in early midlife. Cannabis dependence was not linked to traffic-related convictions. Associations were not explained by socioeconomic adversity, childhood psychopathology, achievement orientation, or family structure; cannabis-related criminal convictions; early onset of cannabis dependence; or comorbid substance dependence. Cannabis dependence was associated with more financial difficulties than alcohol dependence; no difference was found in risks for other economic or social problems. Cannabis dependence is not associated with fewer harmful economic and social problems than alcohol dependence. PMID:28008372
Cousijn, Janna; Snoek, Robin W M; Wiers, Reinout W
Experimental laboratory studies suggest that the approach bias (relatively fast approach responses) toward substance-related materials plays an important role in problematic substance use. How this bias is moderated by intention to use versus recent use remains unknown. Moreover, the relationship between approach bias and other motivational processes (satiation and craving) and executive functioning remains unclear. The aim of this study was to investigate the cannabis approach bias before and after cannabis use in real-life setting (Amsterdam coffee shops) and to assess the relationship between approach bias, craving, satiation, cannabis use, and response inhibition. Cannabis, tobacco, and neutral approach and avoidance action tendencies were measured with the Approach Avoidance Task and compared between 42 heavy cannabis users with the intention to use and 45 heavy cannabis users shortly after cannabis use. The classical Stroop was used to measure response inhibition. Multiple regression analyses were conducted to investigate relationships between approach bias, satiation, craving, cannabis use, and response inhibition. In contrast to the hypotheses, heavy cannabis users with the intention to use did not show a cannabis approach bias, whereas intoxicated cannabis users did show an approach bias regardless of image category. This could be attributed to a general slowing of avoidance action tendencies. Moreover, craving was negatively associated with the approach bias, and no relationships were observed between the cannabis approach bias, satiation, prior cannabis use, and response inhibition. Cannabis intoxication in a real-life setting inhibited general avoidance. Expression of the cannabis approach bias appeared not to be modulated by satiation or response inhibition.
José Alexandre Crippa
-induced pathophysiological changes. A computer literature review was conducted in the MEDLINE and PsycLIT databases between 1966 and November of 2004 with the search terms 'cannabis', 'marijuana', 'neuroimaging', 'magnetic resonance', 'computed tomography', 'positron emission tomography', 'single photon emission computed tomography", 'SPET', 'MRI' and 'CT'. Structural neuroimaging studies have yielded conflicting results. Most studies report no evidence of cerebral atrophy or regional changes in tissue volumes, and one study suggested that long-term users who started regular use on early adolescence have cerebral atrophy as well as reduction in gray matter. However, several methodological shortcomings limit the interpretation of these results.Functional neuroimaging studies have reported increases in neural activity in regions that may be related with cannabis intoxication or mood-change effects (orbital and mesial frontal lobes, insula, and anterior cingulate and decreases in activity of regions related with cognitive functions impaired during acute intoxication.The important question whether residual neurotoxic effects occur after prolonged and regular use of cannabis remains unclear, with no study addressing this question directly. Better designed neuroimaging studies, combined with cognitive evaluation, may be elucidative on this issue.
Garry, A [Department dIngenierie Biologique, Ecole Polytechnique de Universite de Nice - Sophia Antipolis, 1645 Route des Lucioles, 06410 Biot (France); Virginie Rigourd, V; Aubry, S [Lactarium d' Ile de France, Institut de Puericulture et de Perinatalogie, 26 Boulevard Brune, 75014 Paris (France); Amirouche, A; Fauroux, V [Centre de Recherche Clinique Paris Centre, 89 rue d' Assas, 75006 Paris (France); Serreau, R [Centre de Recherche Clinique Paris Centre EA 3620, 89 rue d' Assas 75006 Paris (France)
Cannabis is a drug derived from hemp plant, Cannabis sativa, used both as a recreational drug or as medicine. It is a widespread illegal substance, generally smoked for its hallucinogenic properties. Little is known about the adverse effects of postnatal cannabis exposure throw breast feeding because of a lack of studies in lactating women. The active substance of cannabis is the delta 9 Tetrahydrocannabinol (THC). Some studies conclude that it could decrease motor development of the child at one year of age. Therefore, cannabis use and abuse of other drugs like alcohol, tobacco, or cocaine must be contraindicated during breast feeding. Mothers who use cannabis must stop breast feeding, or ask for medical assistance to stop cannabis use in order to provide her baby with all the benefits of human milk.
Garry, A.; Virginie Rigourd, V.; Aubry, S.; Amirouche, A.; Fauroux, V.; Serreau, R.
Cannabis is a drug derived from hemp plant, Cannabis sativa, used both as a recreational drug or as medicine. It is a widespread illegal substance, generally smoked for its hallucinogenic properties. Little is known about the adverse effects of postnatal cannabis exposure throw breast feeding because of a lack of studies in lactating women. The active substance of cannabis is the delta 9 Tetrahydrocannabinol (THC). Some studies conclude that it could decrease motor development of the child at one year of age. Therefore, cannabis use and abuse of other drugs like alcohol, tobacco, or cocaine must be contraindicated during breast feeding. Mothers who use cannabis must stop breast feeding, or ask for medical assistance to stop cannabis use in order to provide her baby with all the benefits of human milk.
Full Text Available Cannabis is a drug derived from hemp plant, Cannabis sativa, used both as a recreational drug or as medicine. It is a widespread illegal substance, generally smoked for its hallucinogenic properties. Little is known about the adverse effects of postnatal cannabis exposure throw breastfeeding because of a lack of studies in lactating women. The active substance of cannabis is the delta 9 TetraHydroCannabinol (THC. Some studies conclude that it could decrease motor development of the child at one year of age. Therefore, cannabis use and abuse of other drugs like alcohol, tobacco, or cocaine must be contraindicated during breastfeeding. Mothers who use cannabis must stop breastfeeding, or ask for medical assistance to stop cannabis use in order to provide her baby with all the benefits of human milk.
Bourne, Donald; Plinke, Wesley; Hooker, Elizabeth R; Nielson, Carrie M
Cannabis use is rising in the USA. Its relationship to cannabinoid signaling in bone cells implies its use could affect bone mineral density (BMD) in the population. In a national survey of people ages 20-59, we found no association between self-reported cannabis use and BMD of the hip or spine. Cannabis is the most widely used illegal drug in the USA, and its recreational use has recently been approved in several US states. Cannabinoids play a role in bone homeostasis. We aimed to determine the association between cannabis use and BMD in US adults. In the National Health and Nutrition Examination Survey 2007-2010, 4743 participants between 20 and 59 years old, history of cannabis use was categorized into never, former (previous use, but not in last 30 days), light (1-4 days of use in last 30 days), and heavy (≥5 days of use in last 30 days). Multivariable linear regression was used to test the association between cannabis use and DXA BMD of the proximal femur and lumbar spine with adjustment for age, sex, BMI, and race/ethnicity among other BMD determinants. Sixty percent of the population reported ever using cannabis; 47% were former users, 5% were light users, and 7% were heavy users. Heavy cannabis users were more likely to be male, have a lower BMI, increased daily alcohol intake, increased tobacco pack-years, and were more likely to have used other illegal drugs (cocaine, heroin, or methamphetamines). No association between cannabis and BMD was observed for any level of use (p ≥ 0.28). A history of cannabis use, although highly prevalent and related to other risk factors for low BMD, was not independently associated with BMD in this cross-sectional study of American men and women.
Najolia, Gina M; Buckner, Julia D; Cohen, Alex S
Emerging research suggests that cannabis use might be related to psychosis onset in people vulnerable to developing schizophrenia-spectrum disorders. Furthermore, individuals with high-positive and disorganized schizotypy traits report more cannabis use and cannabis-related problems than controls. Social anxiety, a frequently co-occurring schizotypal feature, is related to increased cannabis-related problems in the general population. Building on this research, we explored the impact of social anxiety, measured by the Social Interaction Anxiety Scale (SIAS), and depression and trait anxiety reported on the Brief Symptom Inventory (BSI), on the relationship of schizotypy, measured by the Schizotypy Personality Questionnaire-Brief Revised (SPQ-BR), to cannabis use (n=220 schizotypy, 436 controls) and frequent use and cannabis-related problems among users (n=88 schizotypy, 83 controls) in college undergraduates. Among cannabis users, social anxiety moderated the relationships of schizotypy to frequent cannabis use and more cannabis-related problems in the total schizotypy group, and across high-positive, negative, and disorganized schizotypy subgroups. Depression and trait anxiety also moderated the relationship of schizotypy to frequent cannabis use and more cannabis-related problems, but results varied across high-positive, negative, and disorganized schizotypy subgroups. Results suggest therapeutically targeting negative affective states may be useful in psychosocial intervention for cannabis-related problems in schizotypy. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
Ecker, Anthony H.; Buckner, Julia D.
Objective: Individuals with greater social anxiety are particularly vulnerable to cannabis-related impairment. Descriptive norms (beliefs about others’ use) and injunctive norms (beliefs regarding others’ approval of risky use) may be particularly relevant to cannabis-related behaviors among socially anxious persons if they use cannabis for fear of evaluation for deviating from what they believe to be normative behaviors. Yet, little research has examined the impact of these social norms on the relationships between social anxiety and cannabis use behaviors. Method: The current study investigated whether the relationships of social anxiety to cannabis use and use-related problems varied as a function of social norms. The sample comprised 230 (63.0% female) current cannabis-using undergraduates. Results: Injunctive norms (regarding parents, not friends) moderated the relationship between social anxiety and cannabis-related problem severity. Post hoc probing indicated that among participants with higher (but not lower) social anxiety, those with greater norm endorsement reported the most severe impairment. Injunctive norms (parents) also moderated the relationship between social anxiety and cannabis use frequency such that those with higher social anxiety and lower norm endorsement used cannabis less frequently. Descriptive norms did not moderate the relationship between social anxiety and cannabis use frequency. Conclusions: Socially anxious cannabis users appear to be especially influenced by beliefs regarding parents’ approval of risky cannabis use. Results underscore the importance of considering reference groups and the specific types of norms in understanding factors related to cannabis use behaviors among this vulnerable population. PMID:24411799
Harris, Gregory E; Dupuis, Lise; Mugford, Gerald J; Johnston, Lynn; Haase, David; Page, Ginny; Haldane, Heather; Harris, Nicholas; Midodzi, William K; Dow, Gordon
BACKGROUND: The prevalence of cannabis use in HIV-infected individuals is high and its long-term effects are unclear. METHODS: The prevalence, perceived benefits and consequences, and predictors of cannabis use were studied using a cross-sectional survey in two immunodeficiency clinics in Maritime Canada. RESULTS: Current cannabis use was identified in 38.5% (87 of 226) of participants. Almost all cannabis users (85 of 87 [97.7%]) acknowledged its use for recreational purposes, with 21.8% (19 of 87) reporting medicinal cannabis use. The majority of patients enrolled in the present study reported mild or no symptoms related to HIV (n=179). Overall, 80.5% (70 of 87) of the cannabis-using participants reported a symptom-relieving benefit, mostly for relief of stress, anorexia or pain. Participants consumed a mean (± SD) of 18.3±21.1 g of cannabis per month and spent an average of $105.15±109.87 on cannabis per month. Cannabis use was associated with rural residence, lower income level, driving under the influence of a substance, and consumption of ecstasy and tobacco. Income level, ecstasy use and tobacco use were retained as significant predictors in regression modelling. Cannabis use was not associated with adverse psychological outcomes. DISCUSSION: Prolonged previous cannabis consumption and the substantial overlap between recreational and medicinal cannabis use highlight the challenges in obtaining a tenable definition of medicinal cannabis therapy. PMID:24634690
Full Text Available Cannabis use is increasingly pervasive among adolescents today, even more common than cigarette smoking. The evolving policy surrounding the legalization of cannabis reaffirms the need to understand the relationship between cannabis exposure early in life and psychiatric illnesses. Cannabis contains psychoactive components, notably Δ9-tetrahydrocannbinol (THC, that interfere with the brain’s endogenous endocannabinoid system, which is critically involved in both pre- and post-natal neurodevelopment. Consequently, THC and related compounds could potentially usurp normal adolescent neurodevelopment, shifting the brain’s developmental trajectory towards a disease-vulnerable state, predisposing early cannabis-users to motivational, affective and psychotic disorders. Numerous human studies, including prospective longitudinal studies, demonstrate that early cannabis use is associated with major depressive disorder and drug addiction. A strong association between schizophrenia and cannabis use is also apparent, especially when considering genetic factors that interact with this environmental exposure. These human studies set a foundation for carefully controlled animal studies which demonstrate similar patterns following early cannabinoid exposure. Given the vulnerable nature of adolescent neurodevelopment and the persistent changes that follow early cannabis exposure, the experimental findings outlined should be carefully considered by policymakers. In order to fully address the growing issues of psychiatric illnesses and to ensure a healthy future, measures should be taken to reduce cannabis use among teens.
Schlienz, Nicolas J; Lee, Dustin C; Stitzer, Maxine L; Vandrey, Ryan
There is a clear need for advancing the treatment of cannabis use disorders. Prior research has demonstrated that dronabinol (oral THC) can dose-dependently suppress cannabis withdrawal and reduce the acute effects of smoked cannabis. The present study was conducted to evaluate whether high-dose dronabinol could reduce cannabis self-administration among daily users. Non-treatment seeking daily cannabis users (N = 13) completed a residential within-subjects crossover study and were administered placebo, low-dose dronabinol (120 mg/day; 40 mg tid), or high-dose dronabinol (180-240 mg/day; 60-80 mg tid) for 12 consecutive days (order counterbalanced). During each 12-day dronabinol maintenance phase, participants were allowed to self-administer smoked cannabis containing <1% THC (placebo) or 5.7% THC (active) under forced-choice (drug vs. money) or progressive ratio conditions. Participants self-administered significantly more active cannabis compared with placebo in all conditions. When active cannabis was available, self-administration was significantly reduced during periods of dronabinol maintenance compared with placebo maintenance. There was no difference in self-administration between the low- and high-dose dronabinol conditions. Chronic dronabinol dosing can reduce cannabis self-administration in daily cannabis users and suppress withdrawal symptoms. Cannabinoid agonist medications should continue to be explored for therapeutic utility in the treatment of cannabis use disorders. Copyright © 2018 Elsevier B.V. All rights reserved.
Kahan, Meldon; Srivastava, Anita; Spithoff, Sheryl; Bromley, Lisa
Objective To offer preliminary guidance on prescribing smoked cannabis for chronic pain before the release of formal guidelines. Quality of evidence We reviewed the literature on the analgesic effectiveness of smoked cannabis and the harms of medical and recreational cannabis use. We developed recommendations on indications, contraindications, precautions, and dosing of smoked cannabis, and categorized the recommendations based on levels of evidence. Evidence is mostly level II (well conducted observational studies) and III (expert opinion). Main message Smoked cannabis might be indicated for patients with severe neuropathic pain conditions who have not responded to adequate trials of pharmaceutical cannabinoids and standard analgesics (level II evidence). Smoked cannabis is contraindicated in patients who are 25 years of age or younger (level II evidence); who have a current, past, or strong family history of psychosis (level II evidence); who have a current or past cannabis use disorder (level III evidence); who have a current substance use disorder (level III evidence); who have cardiovascular or respiratory disease (level III evidence); or who are pregnant or planning to become pregnant (level II evidence). It should be used with caution in patients who smoke tobacco (level II evidence), who are at increased risk of cardiovascular disease (level III evidence), who have anxiety or mood disorders (level II evidence), or who are taking higher doses of opioids or benzodiazepines (level III evidence). Cannabis users should be advised not to drive for at least 3 to 4 hours after smoking, for at least 6 hours after oral ingestion, and for at least 8 hours if they experience a subjective “high” (level II evidence). The maximum recommended dose is 1 inhalation 4 times per day (approximately 400 mg per day) of dried cannabis containing 9% delta-9-tetrahydrocannabinol (level III evidence). Physicians should avoid referring patients to “cannabinoid” clinics (level
Boidi, María Fernanda; Queirolo, Rosario; Cruz, José Miguel
In 2013, Uruguay became the first country to fully regulate the cannabis market, which now operates under state control. Cannabis can be legally acquired in three ways: growing it for personal use (self-cultivation), cannabis club membership, and from pharmacies (not yet implemented). Users must be entered into a confidential official registry to gain access. This article presents findings of a Respondent Driven Sample survey of 294 high-frequency cannabis consumers in the Montevideo metropolitan area. Frequent consumers resort to more than one method for acquiring cannabis, with illegal means still predominating after 1 year of the new regulation law. Cannabis users overwhelmingly support the current regulation, but many of them are reluctant to register. Some of the attitudes and behaviors of the high-frequency consumers pose a challenge to the success of the cannabis law. Individuals relying on more than one method of access defy the single access clause, a prerequisite for legal use, while the maximum amount of cannabis individuals can access monthly seems too high even for most frequent consumers, which might promote the emergence of a grey market. Reluctance to register among a significant proportion of high-frequency consumers raises doubts about the law's ability to achieve its stated objectives. Copyright © 2016 Elsevier B.V. All rights reserved.
Lau, Nicholas; Sales, Paloma; Averill, Sheigla; Murphy, Fiona; Sato, Sye-Ok; Murphy, Sheigla
Substitution is operationalised as a conscious choice made by users to use one drug instead of, or in conjunction with another based on: perceived safety, level of addiction potential, effectiveness in relieving symptoms, access and level of acceptance. Harm reduction is a set of strategies that aim to minimise problems associated with drug use while recognising that for some users, abstinence may be neither a realistic nor a desirable goal. In this paper, we aim for deeper understandings of older adult cannabis users' beliefs and substitution practices as part of the harm reduction framework. We present selected findings from our qualitative study of Baby Boomer (born 1946-1964) marijuana users in the San Francisco Bay Area. Although the sample consisted of primary cannabis users, many had personal experience with other drugs throughout their lifetimes. Data collection consisted of an audio-recorded, semi-structured in-depth life history interview followed by a questionnaire and health survey. Qualitative interviews were analysed to discover users' harm reduction beliefs and cannabis substitution practices. Study participants described using cannabis as a safer alternative for alcohol, illicit drugs and pharmaceuticals based on their perceptions of less adverse side effects, low-risk for addiction and greater effectiveness at relieving symptoms, such as chronic pain. Cannabis substitution can be an effective harm reduction method for those who are unable or unwilling to stop using drugs completely. More research is needed on cannabis as a safer alternative. © 2015 Australasian Professional Society on Alcohol and other Drugs.
Reece, Albert Stuart
Cannabis is the most widely used illicit drug worldwide. As societies reconsider the legal status of cannabis, policy makers and clinicians require sound knowledge of the acute and chronic effects of cannabis. This review focuses on the latter. A systematic review of Medline, PubMed, PsychInfo, and Google Scholar using the search terms "cannabis," "marijuana," "marihuana," "toxicity," "complications," and "mechanisms" identified 5,198 papers. This list was screened by hand, and papers describing mechanisms and those published in more recent years were chosen preferentially for inclusion in this review. There is evidence of psychiatric, respiratory, cardiovascular, and bone toxicity associated with chronic cannabis use. Cannabis has now been implicated in the etiology of many major long-term psychiatric conditions including depression, anxiety, psychosis, bipolar disorder, and an amotivational state. Respiratory conditions linked with cannabis include reduced lung density, lung cysts, and chronic bronchitis. Cannabis has been linked in a dose-dependent manner with elevated rates of myocardial infarction and cardiac arrythmias. It is known to affect bone metabolism and also has teratogenic effects on the developing brain following perinatal exposure. Cannabis has been linked to cancers at eight sites, including children after in utero maternal exposure, and multiple molecular pathways to oncogenesis exist. Chronic cannabis use is associated with psychiatric, respiratory, cardiovascular, and bone effects. It also has oncogenic, teratogenic, and mutagenic effects all of which depend upon dose and duration of use.
... progression of MS: Effect of oral dronabinol (a synthetic Cannabis/marijuana derivative) on progression in progressive MS: Previous ... the evidence regarding marijuana and its derivatives: Oral cannabis extract and synthetic THC (tetrahydrocannabinol — a major active component of cannabis) ...
Galván, Gonzalo; Guerrero-Martelo, Manuel; Vásquez De la Hoz, Francisco
The vision of cannabis as a soft drug is due to the low risk perception that young and old people have of the drug. This perception is based on erroneous beliefs that people have about the drug. To compare the beliefs of cannabis use and consequences among adolescents with a lifetime prevalence of cannabis use and those without a lifetime prevalence of cannabis use. Quantitative, descriptive and cross-sectional study with a probability sample of 156 high school students who completed an ad-hoc questionnaire that included sociodemographic data and 22 questions about the beliefs that young people had about cannabis use and its consequences. The lifetime prevalence of cannabis use was 13.5%. The prevalence group consisted mostly of males. Statistically significant differences between different groups and different beliefs were found. The group with no lifetime prevalence of cannabis use perceived higher risk as regards the damage that cannabis can cause to memory, other cognitive functions, neurons, mental health, and general health. The group with a lifetime prevalence of cannabis use perceived a lower risk as regards the use of cannabis, and think that intelligent people smoke cannabis, and that cannabis has positive effects on the brain, increasing creativity. and is used to cure mental diseases. Those who used cannabis once in their life perceive the use of the substance as less harmful or less potential danger to health compared to those who never consumed. In fact those who consumed at some time even have beliefs that suggest positive effects in those people that consume it. Copyright © 2016 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.
Darke, Shane; Torok, Michelle
Childhood physical abuse (CPA), non-suicidal self-harm and attempted suicide are all highly prevalent amongst injecting drug users (IDU). This paper reported on the association of CPA with self-harm and attempted suicide. Cross-sectional study, with 300 IDU administered a structured interview examining the prevalence of CPA, non-suicidal self-harm and suicide attempts. CPA was reported by 74.3%, and severe CPA by 40.3%. A history of non-suicidal self-harm was reported by 23.7%, and 25.7% had attempted suicide. Non-suicidal self-harm preceded the suicide attempt in 83.3% of cases where both had occurred. Independent correlates of non-suicidal self-harm were: female gender (OR 3.62), avoided home due to conflict (OR 2.28) and more extensive polydrug use (OR 1.32). Independent correlates of attempted suicide were: severe CPA (OR 3.18), frequent CPA (OR 2.54), avoided home due to conflict (OR 3.95), female gender (OR 2.99), a positive screen for Conduct Disorder (OR 3.53), and more extensive polydrug use (OR 1.52). Those presenting to treatment agencies are highly likely to have a history of CPA, that may still influence their behaviours. Screening for histories of CPA and non-suicidal self-harm appears warranted when determining suicide risk for this population. At the population level, reductions in the rate of CPA, could possibly reduce the rate of subsequent suicidality. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Lucas, Philippe; Walsh, Zach
In 2014 Health Canada replaced the Marihuana for Medical Access Regulations (MMAR) with the Marihuana for Medical Purposes Regulations (MMPR). One of the primary changes in the new program has been to move from a single Licensed Producer (LP) of cannabis to multiple Licensed Producers. This is the first comprehensive survey of patients enrolled in the MMPR. Patients registered to purchase cannabis from Tilray, a federally authorized Licenced Producer (LP) within the MMPR, were invited to complete an online survey consisting of 107 questions on demographics, patterns of use, and cannabis substitution effect. The survey was completed by 271 respondents. Cannabis is perceived to be an effective treatment for diverse conditions, with pain and mental health the most prominent. Findings include high self-reported use of cannabis as a substitute for prescription drugs (63%), particularly pharmaceutical opioids (30%), benzodiazepines (16%), and antidepressants (12%). Patients also reported substituting cannabis for alcohol (25%), cigarettes/tobacco (12%), and illicit drugs (3%). A significant percentage of patients (42%) reported accessing cannabis from illegal/unregulated sources in addition to access via LPs, and over half (55%) were charged to receive a medical recommendation to use cannabis, with nearly 25% paying $300 or more. The finding that patients report its use as a substitute for prescription drugs supports prior research on medical cannabis users; however, this study is the first to specify the classes of prescription drugs for which cannabis it is used as a substitute, and to match this substitution to specific diagnostic categories. The findings that some authorized patients purchase cannabis from unregulated sources and that a significant percentage of patients were charged for medical cannabis recommendations highlight ongoing policy challenges for this federal program. Copyright © 2017 Elsevier B.V. All rights reserved.
Troup, Lucy J.; Bastidas, Stephanie; Nguyen, Maia T.; Andrzejewski, Jeremy A.; Bowers, Matthew; Nomi, Jason S.
The effect of cannabis on emotional processing was investigated using event-related potential paradigms (ERPs). ERPs associated with emotional processing of cannabis users, and non-using controls, were recorded and compared during an implicit and explicit emotional expression recognition and empathy task. Comparisons in P3 component mean amplitudes were made between cannabis users and controls. Results showed a significant decrease in the P3 amplitude in cannabis users compared to controls. Specifically, cannabis users showed reduced P3 amplitudes for implicit compared to explicit processing over centro-parietal sites which reversed, and was enhanced, at fronto-central sites. Cannabis users also showed a decreased P3 to happy faces, with an increase to angry faces, compared to controls. These effects appear to increase with those participants that self-reported the highest levels of cannabis consumption. Those cannabis users with the greatest consumption rates showed the largest P3 deficits for explicit processing and negative emotions. These data suggest that there is a complex relationship between cannabis consumption and emotion processing that appears to be modulated by attention. PMID:26926868
Griffith-Lendering, Merel F H; Huijbregts, Stephan C J; Huizink, Anja C; Ormel, Hans; Verhulst, Frank C; Vollebergh, Wilma A M; Swaab, Hanna
Social skills (cooperation, assertion, and self-control) were assessed by teachers for a longitudinal cohort of (pre)adolescents, with measurements at average ages 11.1 (baseline) and 16.3 years (follow-up). Prospective associations with participants' self-reported use of cannabis, (age of) onset of cannabis use, and frequency of use at follow-up were examined using multinomial logistic regression analyses. Teacher-reported social skills predicted different aspects of cannabis use independent of better known factors such as presence of externalizing behavior and use of other substances. The direction of associations depended on the type of social skill. Good cooperation skills during early adolescence were associated with a reduced risk of lifetime cannabis use and a reduced risk of using cannabis on a regular basis. On the other hand, assertion at age 11 increased the risk of lifetime cannabis use and of using cannabis on an experimental basis.
López, Rodrigo; Baelum, Vibeke
The aim of this experiment was to investigate the association between cannabis use and destructive periodontal disease among adolescents. Data from a population screening examination carried out among Chilean high school students from the Province of Santiago were used to determine whether there was an association between the use of cannabis and signs of periodontal diseases as defined by (1) the presence of necrotizing ulcerative gingival (NUG) lesions or (2) the presence of clinical attachment loss (CAL) > or =3 mm. The cannabis exposures variables considered were "Ever use of cannabis" (yes/no) and "Regular use of cannabis" (yes/no). The associations were investigated using multiple logistic regression analyses adjusted for age, gender, paternal income, paternal education, frequency of tooth-brushing and time since last dental visit. Multiple logistic regression analyses showed that "Ever use of cannabis" was significantly negatively associated with the presence of NUG lesions (OR=0.47 [0.2;0.9]) among non-smokers only. No significant associations were observed between the presence of CAL > or =3 mm and cannabis use in either of the smoking groups. There was no evidence to suggest that the use of cannabis is positively associated with periodontal diseases in this adolescent population.
The cannabis plant (Cannabis sativa L.) has a long history as a recreational drug, but also as part of traditional medicine in many cultures. Nowadays, it is used by a large number of patients worldwide, to ameliorate the symptoms of diseases varying from cancer and AIDS to multiple sclerosis and migraine. The discovery of cannabinoid-receptors and the endocannabinoid system have opened up a new and exciting field of research. But despite the pharmaceutical potential of cannabis, its classifi...
Abdul I. Mahmad
Conclusion: Our patient reported the vomiting episodes were associated with the regular usage of cannabis over 19 years. One theory on the effectiveness of hot showers states that it may correct the disequilibrium of the thermoregulatory system in the hypothalamus. Another theory suggests that the concept of peripheral vasodilation and redistribution of blood flow from the splanchnic circulation to peripheral musculature helps decrease vomiting. This research gap shows that further studying of cannabis and its effects are still needed.
Wouters, M.; Korf, D.J.
In the Netherlands, small amounts of cannabis can be lawfully sold to consumers in so-called coffee shops. Many communities in the country do not have coffee shops, and users under 18 years of age are not allowed to enter coffee shops. A field sample of 773 current cannabis users were interviewed in
Shiplo, Samantha; Asbridge, Mark; Leatherdale, Scott T; Hammond, David
The mode of medical cannabis delivery-whether cannabis is smoked, vapourized, or consumed orally-may have important implications for its therapeutic efficacy and health risks. However, there is very little evidence on current patterns of use among Canadian medical cannabis users, particularly with respect to modes of delivery. The current study examined modes of medical cannabis delivery following regulatory changes in 2014 governing how Canadians access medical cannabis. A total of 364 approved adult Canadian medical cannabis users completed an online cross-sectional survey between April and June 2015. The survey examined patterns of medical cannabis use, modes of delivery used, and reasons for use. Participants were recruited through a convenience sample from nine Health Canada licensed producers. Using a vapourizer was the most popular mode of delivery for medical cannabis (53 %), followed by smoking a joint (47 %). The main reason for using a vapourizer was to reduce negative health consequences associated with smoking. A majority of current vapourizer users reported using a portable vapourizer (67.2 %), followed by a stationary vapourizer (41.7 %), and an e-cigarette or vape pen (19.3 %). Current use of a vapourizer was associated with fewer respiratory symptoms (AOR = 1.28, 95 % CI 1.05-1.56, p = 0.01). The findings suggest an increase in the popularity of vapourizers as the primary mode of delivery among approved medical users. Using vapourizers has the potential to prevent some of the adverse respiratory health consequences associated with smoking and may serve as an effective harm reduction method. Monitoring implications of such current and future changes to medical cannabis regulations may be beneficial to policymakers.
Full Text Available Abstract Background The mode of medical cannabis delivery—whether cannabis is smoked, vapourized, or consumed orally—may have important implications for its therapeutic efficacy and health risks. However, there is very little evidence on current patterns of use among Canadian medical cannabis users, particularly with respect to modes of delivery. The current study examined modes of medical cannabis delivery following regulatory changes in 2014 governing how Canadians access medical cannabis. Methods A total of 364 approved adult Canadian medical cannabis users completed an online cross-sectional survey between April and June 2015. The survey examined patterns of medical cannabis use, modes of delivery used, and reasons for use. Participants were recruited through a convenience sample from nine Health Canada licensed producers. Results Using a vapourizer was the most popular mode of delivery for medical cannabis (53 %, followed by smoking a joint (47 %. The main reason for using a vapourizer was to reduce negative health consequences associated with smoking. A majority of current vapourizer users reported using a portable vapourizer (67.2 %, followed by a stationary vapourizer (41.7 %, and an e-cigarette or vape pen (19.3 %. Current use of a vapourizer was associated with fewer respiratory symptoms (AOR = 1.28, 95 % CI 1.05–1.56, p = 0.01. Conclusions The findings suggest an increase in the popularity of vapourizers as the primary mode of delivery among approved medical users. Using vapourizers has the potential to prevent some of the adverse respiratory health consequences associated with smoking and may serve as an effective harm reduction method. Monitoring implications of such current and future changes to medical cannabis regulations may be beneficial to policymakers.
The topic of drug addiction or misuse of drugs has numerous far-reaching ramifications into areas such as neuroscience, medicine and therapeutics, toxicology, epidemiology, national and international economics and politics, and the law. The general principles of drug addiction are first summarised. A recurring and intrinsic problem is lack of adequate characterisation of the independent variable, namely the drug taken. Secondly, it is not feasible to allocate subjects randomly to treatments. Thirdly, the heterogeneity of different forms of addiction precludes facile generalisations. "A problem drug user is anyone who experiences social, psychological, physical, or legal problems related to intoxication, and/or regular excessive consumption, and/or dependence as a consequence of their use of drugs" (UK Advisory Council on Misuse of Drugs, 1982). Cannabis is a genus of flowering plants whose products are used as recreational drugs. Claims have been made for a range of therapeutic properties. Its two main active principles are delta9 - tetrahydrocannabinol (THC) and cannabidiol (CBD). These compounds have contrasting pharmacological properties. THC is suspected of causing psychotic phenomena, but CBD seems more sedative and may even be antipsychotic. The past use of cannabis, particularly the concentrations of THC and CBD, can be monitored with hair analysis. Recent studies involving the administration of THC and CBD to human subjects are reviewed. Suggestions are made for further research into the pharmacology and toxicology of CBD. Such data may also point to a more rational evidence-based approach to the legal control of cannabis preparations.
Psychosis is one of the most serious among the adverse effects associated with cannabis use. The association between cannabis use and psychosis has been variously explored in a series of recent meta-analyses. The results of these meta-analyses show that persons who develop psychosis experience onset of psychosis about 2-3 years earlier if they are cannabis users; this effect is not observed with alcohol or other substance use. Higher levels of cannabis use are associated with greater risk of psychosis. Current cannabis abuse or dependence (but not past use or lower levels of current use) increases the risk of transition into psychosis in persons at ultrahigh risk of psychosis. About a third of patients with first-episode psychosis are cannabis users, and, at follow-up, about half of these users are found to continue their cannabis use. Continued cannabis use (in those who are treated after developing psychosis) is associated with higher risk of relapse into psychosis, and discontinuation of cannabis use reduces the risk of relapse to that in cannabis nonusers. Finally, persons with psychosis who continue to use cannabis have more severe positive symptoms and poorer levels of functioning. Because experimental studies in humans show that cannabinoids and cannabis can induce psychotic symptoms, it is reasonable to assume that the epidemiologic data indicate a causal effect of cannabis in anticipating, triggering, or exacerbating psychosis in vulnerable individuals and in worsening the course and outcome of the illness in those who continue to use the substance. Given the public health implications of these findings, the trend to legalize medical marijuana must be viewed with concern, and efforts are necessary to educate patients and the public about the serious mental and physical health risks associated with cannabis use and abuse. © Copyright 2016 Physicians Postgraduate Press, Inc.
Núñez, Christian; Ochoa, Susana; Huerta-Ramos, Elena; Baños, Iris; Barajas, Ana; Dolz, Montserrat; Sánchez, Bernardo; Del Cacho, Núria; Usall, Judith
First episode patients and patients with schizophrenia exhibit increased rates of cannabis use compared to the general population. Contrary to what has been reported in studies with healthy people, most of the published studies so far have reported no impairments or even beneficial effects on neurocognition associated with cannabis consumption in psychotic patients. However, these studies did not address the effects of very high cannabis consumption. Our aim in this study was to assess the effects on neurocognition of medium and heavy cannabis consumption in first psychotic episode patients. A total of 74 patients were included in the study and assigned to three different groups according to their mean cannabis consumption during the last year (non-users, medium users, and heavy users). Participants were administered verbal memory and other neurocognitive tasks. Heavy cannabis users were significantly impaired in all the verbal memory measures with respect to non-users, including immediate (p = .026), short-term (p = .005), and long-term (p = .002) memory. There were no significant differences between medium and non-users. Moreover, non-users performed better than all cannabis users in the arithmetic task (p = .020). Heavy cannabis consumption was associated with more commission errors in the continuous performance task (CPT) (p = .008) and more time to complete trail making test A (TMT-A) (p = .008), compared to the group of medium users. Heavy cannabis consumption seems to impair verbal memory in first psychotic episode patients. Heavy users also perform worse than medium users in other neurocognitive tasks. Based on the results and the available evidence, a dose-related effect of cannabis consumption is suggested.
Pacek, Lauren R; Towe, Sheri L; Hobkirk, Andrea L; Nash, Denis; Goodwin, Renee D
Little is known about cannabis use frequency, medical cannabis use, or correlates of use among persons living with HIV (PLWH) in United States nationally representative samples. Data came from 626 PLWH from the 2005-2015 National Survey on Drug Use and Health. Logistic regression identified characteristics associated with frequency of cannabis use. Chi-squares identified characteristics associated with medial cannabis use. Non-daily and daily cannabis use was reported by 26.9% and 8.0%. Greater perceived risk of cannabis use was negatively associated with daily and non-daily use. Younger age, substance use, and binge drinking were positively associated with non-daily cannabis use. Smoking and depression were associated with non-daily and daily use. One-quarter reported medical cannabis use. Medical users were more likely to be White, married, and nondrinkers. Cannabis use was common among PLWH. Findings help to differentiate between cannabis users based on frequency of use and medical versus recreational use.
van der Pol, Peggy; Liebregts, Nienke; de Graaf, Ron; Korf, Dirk J; van den Brink, Wim; van Laar, Margriet
To assess the reliability and validity of self-reported cannabis dose and potency measures. Cross-sectional study comparing self-reports with objective measures of amount of cannabis and delta-9-tetrahydrocannabinol (THC) concentration. Ecological study with assessments at participants' homes or in a coffee shop. Young adult frequent cannabis users (n = 106) from the Dutch Cannabis Dependence (CanDep) study. The objectively measured amount of cannabis per joint (dose in grams) was compared with self-reported estimates using a prompt card and average number of joints made from 1 g of cannabis. In addition, objectively assessed THC concentration in the participant's cannabis was compared with self-reported level of intoxication, subjective estimate of cannabis potency and price per gram of cannabis. Objective estimates of doses per joint (0.07-0.88 g/joint) and cannabis potency (1.1-24.7%) varied widely. Self-reported measures of dose were imprecise, but at group level, average dose per joint was estimated accurately with the number of joints made from 1 g [limit of agreement (LOA) = -0.02 g, 95% confidence interval (CI) = -0.29; 0.26], whereas the prompt card resulted in serious underestimation (LOA = 0.14 g, 95% CI = -0.10; 0.37). THC concentration in cannabis was associated with subjective potency ['average' 3.77% (P = 0.002) and '(very) strong' 5.13% more THC (P cannabis] and with cannabis price (about 1% increase in THC concentration per euro spent on 1 g of cannabis, P cannabis use appear at best to be associated weakly with objective measures. Of the self-report measures, number of joints per gram, cannabis price and subjective potency have at least some validity. © 2013 Society for the Study of Addiction.
The Victorian Adolescent Health Cohort Study (VAHCS) is a long-term Australian cohort study that has documented cannabis use in young Australians from the mid-teens to the mid-30s. The study findings have described the natural history of early cannabis use, remission, and escalation and the social and mental health consequences of different patterns of use. The adverse consequences of cannabis use are most clear-cut in heavy early adolescent users. These consequences include educational failure, persisting mental health problems, and progression to other substance use. For later onset and occasional users, the risks are lower and appear to entail modest elevations in risk for other drug use compared with never users. With growing evidence of health consequences, there is a strong case for actions around early heavy adolescent users. Prevention of early use, identification and treatment of early heavy users, and harm reduction through diversion of early heavy users away from the custodial justice system into health care are all priority responses. PMID:27254840
Strickland, Justin C; Lile, Joshua A; Stoops, William W
Few studies have simultaneously evaluated delay discounting and behavioral economic demand to determine their unique contribution to drug use. A recent study in cannabis users found that monetary delay discounting uniquely predicted cannabis dependence symptoms, whereas cannabis demand uniquely predicted use frequency. This study sought to replicate and extend this research by evaluating delay discounting and behavioral economic demand measures for multiple commodities and including a use quantity measure. Amazon.com's Mechanical Turk was used to sample individuals reporting recent cannabis use (n=64) and controls (n=72). Participants completed measures of monetary delay discounting as well as alcohol and cannabis delay discounting and demand. Cannabis users and controls did not differ on monetary delay discounting or alcohol delay discounting and demand. Among cannabis users, regression analyses indicated that cannabis delay discounting uniquely predicted use severity, whereas cannabis demand uniquely predicted use frequency and quantity. These effects remained significant after controlling for other delay discounting and demand measures. This research replicates previous outcomes relating delay discounting and demand with cannabis use and extends them by accounting for the contribution of multiple commodities. This research also demonstrates the ability of online crowdsourcing methods to complement traditional human laboratory techniques. Copyright © 2017 Elsevier B.V. All rights reserved.
Martell, K.; Fairchild, A.; LeGerrier, B.; Sinha, R.; Baker, S.; Liu, H.; Ghose, A.; Olivotto, I.A.; Kerba, M.
Background A comprehensive assessment of cannabis use by patients with cancer has not previously been reported. In this study, we aimed to characterize patient perspectives about cannabis and its use. Methods An anonymous survey about cannabis use was offered to patients 18 years of age and older attending 2 comprehensive and 2 community cancer centres, comprising an entire provincial health care jurisdiction in Canada (ethics id: hreba-17011). Results Of 3138 surveys distributed, 2040 surveys were returned (65%), with 1987 being sufficiently complete for analysis (response rate: 63%). Of the respondents, 812 (41%) were less than 60 years of age; 45% identified as male, and 55% as female; and 44% had completed college or higher education. Of respondents overall, 43% reported any lifetime cannabis use. That finding was independent of age, sex, education level, and cancer histology. Cannabis was acquired through friends (80%), regulated medical dispensaries (10%), and other means (6%). Of patients with any use, 81% had used dried leaves. Of the 356 patients who reported cannabis use within the 6 months preceding the survey (18% of respondents with sufficiently complete surveys), 36% were new users. Their reasons for use included cancer-related pain (46%), nausea (34%), other cancer symptoms (31%), and non-cancer-related reasons (56%). Conclusions The survey demonstrated that prior cannabis use was widespread among patients with cancer (43%). One in eight respondents identified at least 1 cancer-related symptom for which they were using cannabis.
Barrus, Daniel G.; Capogrossi, Kristen L.; Cates, Sheryl C.; Gourdet, Camille K.; Peiper, Nicholas C.; Novak, Scott P.; Lefever, Timothy W.; Wiley, Jenny L.
Food products containing cannabis extract (edibles) have emerged as a popular and lucrative facet of the legalized market for both recreational and medicinal cannabis. The many formulations of cannabis extracts used in edibles present a unique regulatory challenge for policy makers. Though edibles are often considered a safe, discreet, and effective means of attaining the therapeutic and/or intoxicating effects of cannabis without exposure to the potentially harmful risks of cannabis smoking, little research has evaluated how ingestion differs from other methods of cannabis administration in terms of therapeutic efficacy, subjective effects, and safety. The most prominent difference between ingestion and inhalation of cannabis extracts is the delayed onset of drug effect with ingestion. Consumers often do not understand this aspect of edible use and may consume a greater than intended amount of drug before the drug has taken effect, often resulting in profoundly adverse effects. Written for the educated layperson and for policy makers, this paper explores the current state of research regarding edibles, highlighting the promises and challenges that edibles present to both users and policy makers, and describes the approaches that four states in which recreational cannabis use is legal have taken regarding regulating edibles. PMID:28127591
Bonnet, Udo; Preuss, Ulrich W
The cannabis withdrawal syndrome (CWS) is a criterion of cannabis use disorders (CUDs) (Diagnostic and Statistical Manual of Mental Disorders – Fifth Edition) and cannabis dependence (International Classification of Diseases [ICD]-10). Several lines of evidence from animal and human studies indicate that cessation from long-term and regular cannabis use precipitates a specific withdrawal syndrome with mainly mood and behavioral symptoms of light to moderate intensity, which can usually be treated in an outpatient setting. Regular cannabis intake is related to a desensitization and downregulation of human brain cannabinoid 1 (CB1) receptors. This starts to reverse within the first 2 days of abstinence and the receptors return to normal functioning within 4 weeks of abstinence, which could constitute a neurobiological time frame for the duration of CWS, not taking into account cellular and synaptic long-term neuroplasticity elicited by long-term cannabis use before cessation, for example, being possibly responsible for cannabis craving. The CWS severity is dependent on the amount of cannabis used pre-cessation, gender, and heritable and several environmental factors. Therefore, naturalistic severity of CWS highly varies. Women reported a stronger CWS than men including physical symptoms, such as nausea and stomach pain. Comorbidity with mental or somatic disorders, severe CUD, and low social functioning may require an inpatient treatment (preferably qualified detox) and post-acute rehabilitation. There are promising results with gabapentin and delta-9-tetrahydrocannabinol analogs in the treatment of CWS. Mirtazapine can be beneficial to treat CWS insomnia. According to small studies, venlafaxine can worsen the CWS, whereas other antidepressants, atomoxetine, lithium, buspirone, and divalproex had no relevant effect. Certainly, further research is required with respect to the impact of the CWS treatment setting on long-term CUD prognosis and with respect to
Full Text Available Udo Bonnet,1,2 Ulrich W Preuss3,4 1Department of Psychiatry, Psychotherapy and Psychosomatic Medicine, Evangelisches Krankenhaus Castrop-Rauxel, Academic Teaching Hospital of the University of Duisburg-Essen, Castrop-Rauxel, 2Department of Psychiatry and Psychotherapy, Faculty of Medicine, LVR-Hospital Essen, University of Duisburg-Essen, Essen, 3Vitos-Klinik Psychiatrie und Psychotherapie Herborn, Herborn, 4Martin Luther University Halle-Wittenberg, Halle (Saale, Germany Abstract: The cannabis withdrawal syndrome (CWS is a criterion of cannabis use disorders (CUDs (Diagnostic and Statistical Manual of Mental Disorders – Fifth Edition and cannabis dependence (International Classification of Diseases [ICD]-10. Several lines of evidence from animal and human studies indicate that cessation from long-term and regular cannabis use precipitates a specific withdrawal syndrome with mainly mood and behavioral symptoms of light to moderate intensity, which can usually be treated in an outpatient setting. Regular cannabis intake is related to a desensitization and downregulation of human brain cannabinoid 1 (CB1 receptors. This starts to reverse within the first 2 days of abstinence and the receptors return to normal functioning within 4 weeks of abstinence, which could constitute a neurobiological time frame for the duration of CWS, not taking into account cellular and synaptic long-term neuroplasticity elicited by long-term cannabis use before cessation, for example, being possibly responsible for cannabis craving. The CWS severity is dependent on the amount of cannabis used pre-cessation, gender, and heritable and several environmental factors. Therefore, naturalistic severity of CWS highly varies. Women reported a stronger CWS than men including physical symptoms, such as nausea and stomach pain. Comorbidity with mental or somatic disorders, severe CUD, and low social functioning may require an inpatient treatment (preferably qualified detox and
Loflin, Mallory; Earleywine, Mitch; Bonn-Miller, Marcel
The present study is the first to test whether veterans who use cannabis specifically for the purposes of self-medication for their reported PTSD symptoms differ from veterans who use cannabis medicinally for other reasons, or recreationally, in terms of patterns of cannabis use, use of alcohol, and reactivity to written combat trauma reminders. Assessment measures were administered online to a sample of veterans with a history of cannabis use (n=1971). Cued arousal was assessed pre/post via a prompt about combat experiences. Hypotheses were tested using a series of Bonferroni corrected one-way analyses of variance, t-tests, bivariate and partial correlations, and a Chi-square test. Compared to recreational users, veterans who identify as medicinal cannabis users reported greater combat exposure (d=0.56), PTSD symptoms (d=1.02), subjective arousal when cued (d=0.25), and cannabis use (d frequency =0.40; d density =0.42), but less alcohol use (d=0.28). Few differences were observed between medicinal users who reported using for PTSD versus those who reported using for other reasons. Compared to those who use cannabis recreationally, veterans who report that they use cannabis medicinally use more cannabis and endorse significantly more symptoms of arousal following a prompt about combat trauma experiences. Published by Elsevier Ltd.
Tuck, Andrew; Hamilton, Hayley A; Agic, Branka; Ialomiteanu, Anca R; Mann, Robert E
Rates of cannabis use differ around the world; in Ontario, the rate of use has been stable since about 2005. Understanding which population groups are at greater risk for problematic cannabis use can help reduce long-term health effects and service expenses. The aim of this study was to explore differences in cannabis use among Canadian adults of different ethnic origins living in Ontario. Data are based on telephone interviews with 11,560 respondents and are derived from multiple cycles (2005-2011) of the Centre for Addiction and Mental Health's (CAMH) Monitor survey, an ongoing cross-sectional survey of adults in Ontario, Canada, aged 18 years and older. Data were analyzed using bivariate cross-tabulations and logistic regression. Problematic cannabis use was determined with a score of 8+ on the ASSIST-CIS to identify moderate/high problematic users. Lifetime, past year and problematic cannabis use (in the past 3 months) occurs among all ethnic groups: Canadian, East Asian, South East Asian, South Asian, Caribbean, African, East European, South European, North European, and Central West European. When compared to the Canadian group the odds of past year cannabis use was significantly lower for East Asians and South Asians, but higher for the Caribbean group. Significantly higher odds of problematic cannabis use were found for Caribbeans and Northern Europeans compared to Canadians. These results of this study provide an important basis for considering the possible impact of the impending legalization of cannabis in Canada among different ethnic groups. Copyright © 2017 Elsevier B.V. All rights reserved.
van Ours, J.C.
This paper uses a dataset collected among inhabitants of Amsterdam, to study the employment effects of the use of cannabis and cocaine.For females no negative effects of drug use on the employment rate are found.For males there is a negative correlation between past cannabis and cocaine use and
Slijkhuis C; Hoving R; Blok-Tip L; Kaste D de; KCF
Medicinal Cannabis can be legally supplied by pharmacists to patients from the first of September 2003, although still only on prescription. The quality of this product is tested conform the monograph Cannabis flos. In this monograph tests and quality standards, such as characteristics, loss on
The cannabis plant (Cannabis sativa L.) has a long history as a recreational drug, but also as part of traditional medicine in many cultures. Nowadays, it is used by a large number of patients worldwide, to ameliorate the symptoms of diseases varying from cancer and AIDS to multiple sclerosis and
Biehl, Jason R.
Recent legislative successes allowing expanded access to recreational and medicinal cannabis have been associated with its increased use by the public, despite continued debates regarding its safety within the medical and scientific communities. Despite legislative changes, cannabis is most commonly used by smoking, although alternatives to inhalation have also emerged. Moreover, the composition of commercially available cannabis has dramatically changed in recent years. Therefore, developing sound scientific information regarding its impact on lung health is imperative, particularly because published data conducted prior to widespread legalization are conflicting and inconclusive. In this commentary, we delineate major observations of epidemiologic investigations examining cannabis use and the potential associated development of airways disease and lung cancer to highlight gaps in pulmonary knowledge. Additionally, we review major histopathologic alterations related to smoked cannabis and define specific areas in animal models and human clinical translational investigations that could benefit from additional development. Given that cannabis has an ongoing classification as a schedule I medication, federal funding to support investigations of modern cannabis use in terms of medicinal efficacy and safety profile on lung health have been elusive. It is clear, however, that the effects of inhaled cannabis on lung health remain uncertain and given increasing use patterns, are worthy of further investigation. PMID:25996274
Full Text Available Alcohol and cannabis misuse is currently the most frequent co-morbidity disorder of schizophrenia. The following four issues will be dealt with: 1 the neurobiological basis of the psychosis-inducing, pathogenic effects of THC, the agent contained in cannabis products. 2 Can cannabis use - and for comparison alcohol abuse - prematurely trigger or even cause schizophrenia? 3 Are persons genetically liable to schizophrenia, psychosis-prone individuals or young persons before completion of brain development at an increased risk? 4 What consequences does cannabis use have on the symptomatology and further course of schizophrenia? Results from recent literature and the ABC Schizophrenia Study show that the risk for cannabis use in schizophrenia is about twice the size in healthy controls. In most cases cannabis use starts before first admission, in a third of cases before schizophrenia onset. There is an increased affinity to misuse already at the prodromal stage. Cannabis can prematurely trigger schizophrenia onset - on average eight years earlier than in non-use - and cause the illness partly in interaction with predisposing factors. Cannabis use in the course of schizophrenia increases positive symptoms and reduces affective flattening, thus leading to dysfunctional coping in some cases.
Full Text Available Abstract Background Simultaneous use of alcohol and cannabis predicts increased negative consequences for users beyond individual or even concurrent use of the two drugs. Given the widespread use of the drugs and common simultaneous consumption, problems unique to simultaneous use may bear important implications for many substance users. Cognitive expectancies offer a template for future drug use behavior based on previous drug experiences, accurately predicting future use and problems. Studies reveal similar mechanisms underlying both alcohol and cannabis expectancies, but little research examines simultaneous expectancies for alcohol and cannabis use. Whereas research has demonstrated unique outcomes associated with simultaneous alcohol and cannabis use, this study hypothesized that unique cognitive expectancies may underlie simultaneous alcohol and cannabis use. Results: This study examined a sample of 2600 (66% male; 34% female Internet survey respondents solicited through advertisements with online cannabis-related organizations. The study employed known measures of drug use and expectancies, as well as a new measure of simultaneous drug use expectancies. Expectancies for simultaneous use of alcohol and cannabis predicted simultaneous use over and above expectancies for each drug individually. Discussion Simultaneous expectancies may provide meaningful information not available with individual drug expectancies. These findings bear potential implications on the assessment and treatment of substance abuse problems, as well as researcher conceptualizations of drug expectancies. Policies directing the treatment of substance abuse and its funding ought to give unique consideration to simultaneous drug use and its cognitive underlying factors.
Livne, Ofir; Razon, Liat; Rehm, Jürgen; Hasin, Deborah S; Lev-Ran, Shaul
Though high rates of co-occurring cannabis use and depression are well-documented, data regarding the association between cannabis use and dysthymia is scarce. The aim of this cross-sectional study was to explore clinical correlations of cannabis use among individuals with dysthymia, as well as the changes in the association between cannabis use and dysthymia across six decades of birth cohorts. Data were drawn from the National Epidemiologic Survey on Alcohol and Related Conditions-III (NESARC-III; 2012-2013; N = 36,309). Participants were divided into six birth cohorts (1940s-1990s), based on their decade of birth, and individuals with dysthymia were further categorized by 3 levels of lifetime cannabis use: non-users, non-CUD users, and CUD-users. We compared rates of co-occurring psychiatric and substance use disorders among cannabis users vs non-users and conducted logistic regression analyses in order to determine the odds of dysthymia among cannabis users across six decades. Rates of several psychiatric disorders, such as personality disorders, and substance use disorders were higher among individuals with dysthymia who used cannabis compared to those who did not. The interaction between cannabis use (without a CUD) and birth cohort was associated with a decrease in the odds of dysthymia (OR=0.90, 95% CI 0.84-0.97) and remained significant after controlling for confounding variables. Similar changes over time were not demonstrated for CUD users. Likelihood for recall bias and misclassification based on cross-sectional nature of the study and on respondents' self-reports of symptoms throughout their lifetime. Our study's findings demonstrate that the association between cannabis use (but not CUDs) and dysthymia has weakened over time. These findings highlight the need for further research examining changes over time in the relationship between cannabis use and associated psychiatric disorders. Copyright © 2018 Elsevier B.V. All rights reserved.
Camera Ariella A
Full Text Available Abstract Background Cannabis use can frequently have adverse affects in those that use it and these can be amplified by various characteristics of an individual, from demographic and environmental variations to familial predisposition for mental illnesses. Methods The current study of 100 individuals, who were cannabis users during their adolescence and may still be users, was a survey of the self perceived effects of cannabis and their correlates. A reliable family member was also interviewed for determination of family history of various major mental illnesses and substance use. Results As many as 40% of cannabis users had paranoid feelings (suspiciousness when using cannabis, although the most frequent effect was feeling relaxed (46%. Having a familial background for mental illnesses such as depression or schizophrenia did not determine the effects of cannabis nor its pattern of use, although the number of subjects with such a history was small. An age at which an individual began using cannabis did have an effect on how heavily it was used and the heavier the cannabis use, the more likely the individual was also to have had psychotic symptoms after use. There were no sex differences in effects of cannabis. These results are tempered by the reliance on self-report for many of the variables ascertained. Conclusion Cannabis can frequently have negative effects in its users, which can be amplified by certain demographic and/or psychosocial factors. Thus, users with a specific profile may be at a higher risk of unpleasant effects from cannabis use and caution should be noted when cannabis is administered to young people for medicinal purposes.
Colizzi, Marco; Iyegbe, Conrad; Powell, John; Ursini, Gianluca; Porcelli, Annamaria; Bonvino, Aurora; Taurisano, Paolo; Romano, Raffaella; Masellis, Rita; Blasi, Giuseppe; Morgan, Craig; Aitchison, Katherine; Mondelli, Valeria; Luzi, Sonija; Kolliakou, Anna; David, Anthony; Murray, Robin M.; Bertolino, Alessandro; Forti, Marta Di
Both cannabis use and the dopamine receptor (DRD2) gene have been associated with schizophrenia, psychosis-like experiences, and cognition. However, there are no published data investigating whether genetically determined variation in DRD2 dopaminergic signaling might play a role in individual susceptibility to cannabis-associated psychosis. We genotyped (1) a case-control study of 272 patients with their first episode of psychosis and 234 controls, and also from (2) a sample of 252 healthy subjects, for functional variation in DRD2, rs1076560. Data on history of cannabis use were collected on all the studied subjects by administering the Cannabis Experience Questionnaire. In the healthy subjects’ sample, we also collected data on schizotypy and cognitive performance using the Schizotypal Personality Questionnaire and the N-back working memory task. In the case-control study, we found a significant interaction between the rs1076560 DRD2 genotype and cannabis use in influencing the likelihood of a psychotic disorder. Among cannabis users, carriers of the DRD2, rs1076560, T allele showed a 3-fold increased probability to suffer a psychotic disorder compared with GG carriers (OR = 3.07; 95% confidence interval [CI]: 1.22–7.63). Among daily users, T carrying subjects showed a 5-fold increase in the odds of psychosis compared to GG carriers (OR = 4.82; 95% CI: 1.39–16.71). Among the healthy subjects, T carrying cannabis users had increased schizotypy compared with T carrying cannabis-naïve subjects, GG cannabis users, and GG cannabis-naïve subjects (all P ≤ .025). T carrying cannabis users had reduced working memory accuracy compared with the other groups (all P ≤ .008). Thus, variation of the DRD2, rs1076560, genotype may modulate the psychosis-inducing effect of cannabis use. PMID:25829376
Galván, Gonzalo Daniel; Guerrero, Manuel; Pinedo López, Jhon; García, Ricardo
In this cross sectional and descriptive study, secondary school students trom the city of Santa Rosa were questioned about their beliefs about cannabis and their risk perception derived from it. The sample consisted in 83 male and 71 female 17 year-old teenagers. On the one hand, it was found that the highest risk perceptions were related to the legal issues that might arise due to cannabis consumption, and to its effects on neurons. On the other hand, the lowest risk perceptions were associated with the belief/ idea that smoking tobacco affects the lungs more than smoking cannabis, which might create dependence, and its use can cause mental disorders. Several significant differences were found as regards gender, since the female students noticed more risk than male students in that the consumption of cannabis can develop mental disorders, amotivational syndrome, lack of enthusiasm and less satisfaction with life. The teenager's risk perception about cannabis is variable.
Zalesky, Andrew; Solowij, Nadia; Yucel, Murat; Lubman, Dan I.; Takagi, Michael; Harding, Ian H.; Lorenzetti, Valentina; Wang, Ruopeng; Searle, Karissa; Pantelis, Christos; Seal, Marc
Cannabis use typically begins during adolescence and early adulthood, a period when cannabinoid receptors are still abundant in white matter pathways across the brain. However, few studies to date have explored the impact of regular cannabis use on white matter structure, with no previous studies examining its impact on axonal connectivity. The…
Christensen, Lisa B; Rosing, Kasper; Lempert, Susanne M; Hede, Børge
To describe the pattern of dental services provided to 64-65-year-old Danes who are regular users of dental care over a 5-year period, to analyse whether this pattern is associated with socio-demographic and/or socioeconomic factors, and if different uses of dental services are related to dental status and caries experience. Finally, to discuss the future planning of dental services aimed at the increasing population of elderly citizens. [Correction made on 21 March 2014, after first online publication: The sentence 'Data on elderly's dental service are scarce, although increased use is seen and more teeth are present in this age group.' was removed.] A cross-sectional study of all aged 64-65 (n = 37 234) who received a dental examination in 2009 was conducted. Clinical data comprised dental services received under the National Health Insurance reimbursement scheme, dental status and DMFT. Geographical, socio-demographic and socioeconomic data derived from public registers. Almost all received restorations, while periodontal treatment was received by dental services was dominated by periodontal services. Periodontal services were most prevalent in the capital and the most affluent areas. Relatively more extractions were related to low income and persons in least affluent areas. Total number of services was highest among women, persons with ≥20 teeth, persons living in the capital, and where the ratio user per dentist was low. For future planning of dental care for elderly, dental status, geographical and social area-based factors and to some degree gender, income, and education must be taken into consideration as all these factors seem to influence the future demand for dental services. © 2014 John Wiley & Sons A/S and The Gerodontology Association. Published by John Wiley & Sons Ltd.
Meier, Madeline H
High-potency cannabis concentrates are increasingly popular in the United States, and there is concern that use of high-potency cannabis might increase risk for cannabis-related problems. However, little is known about the potential negative consequences of concentrate use. This study reports on associations between past-year use of a high-potency cannabis concentrate, known as butane hash oil (BHO), and cannabis-related problems. A sample of 821 college students were recruited to complete a survey about their health and behavior. Participants who had used cannabis in the past year (33%, n=273) completed questions about their cannabis use, including their use of BHO and cannabis-related problems in eight domains: physical dependence, impaired control, academic-occupational problems, social-interpersonal problems, self-care problems, self-perception, risk behavior, and blackouts. Approximately 44% (n=121) of past-year cannabis users had used BHO in the past year. More frequent BHO use was associated with higher levels of physical dependence (RR=1.8, pcannabis-related academic/occupational problems (RR=1.5, p=0.004), poor self-care (RR=1.3, p=0.002), and cannabis-related risk behavior (RR=1.2, p=0.001). After accounting for sociodemographic factors, age of onset of cannabis use, sensation seeking, overall frequency of cannabis use, and frequency of other substance use, BHO use was still associated with higher levels of physical dependence (RR=1.2, p=0.014). BHO use is associated with greater physiological dependence on cannabis, even after accounting for potential confounders. Longitudinal research is needed to determine if cannabis users with higher levels of physiological dependence seek out BHO and/or if BHO use increases risk for physiological dependence. Copyright © 2017 Elsevier B.V. All rights reserved.
Simpson, Annabelle K; Magid, Viktoriya
Cannabis use in the adolescent population poses a significant threat of addiction potential resulting in altered neurodevelopment. There are multiple mechanisms of treatment of cannabis use disorder including behavioral therapy management and emerging data on treatment via pharmacotherapy. Recognizing the diagnostic criteria for cannabis use disorder, cannabis withdrawal syndrome, and mitigating factors that influence adolescent engagement in cannabis use allows for comprehensive assessment and management in the adolescent population. Copyright © 2016 Elsevier Inc. All rights reserved.
Rafael Faria Sanches
Full Text Available OBJETIVO: Avaliar as relações entre o uso agudo e crônico de cannabis e alterações do humor. MÉTODO: Os artigos foram selecionados por meio de busca eletrônica no indexador PubMed. Capítulos de livros e as listas de referências dos artigos selecionados também foram revisados. RESULTADOS: Observam-se elevados índices de comorbidade entre abuso/dependência de cannabis e transtornos afetivos em estudos transversais e em amostras clínicas. Estudos longitudinais indicam que, em longo prazo, o uso mais intenso de cannabis está relacionado com um risco maior de desenvolvimento de doença bipolar e, talvez, depressão maior em indivíduos inicialmente sem quadros afetivos; porém, os mesmos não encontraram maior risco de uso de cannabis entre aqueles com mania ou depressão sem esta comorbidade. Outra importante observação é que o uso de substâncias psicoativas em bipolares pode estar associado a uma série de características negativas, como dificuldade na recuperação dos sintomas afetivos, maior número de internações, piora na adesão ao tratamento, risco aumentado de suicídio, agressividade e a uma pobre resposta ao lítio. Tratamentos psicossociais e farmacológicos são indicados para o manejo da comorbidade entre cannabis e transtornos afetivos. CONCLUSÃO: As relações entre o uso de cannabis e alterações do humor são observadas tanto epidemiologicamente quanto nos contextos clínicos.OBJECTIVE: Evaluate the relationship between acute and chronic use of cannabis and mood changes. METHOD: Articles were selected by electronic search in PubMed. Chapters in books and reference lists of selected articles were also reviewed. As the research did not involve humans, there was no evaluation by a Research Ethics Committee. RESULTS: High rates of comorbidity between use/abuse/dependence of cannabis and affective disorders in longitudinal studies and in clinical samples were observed. Longitudinal studies indicate that, in long
Aharonovich, Efrat; Garawi, Fatima; Bisaga, Adam; Brooks, Daniel; Raby, Wilfrid N; Rubin, Eric; Nunes, Edward V; Levin, Frances R
Cannabis is the most widely used illicit substance in the United States with especially high prevalence of use among those with psychiatric disorders. Few studies have examined the relationship between concurrent cannabis use and treatment outcome among patients receiving treatment for comorbid substance abuse and psychiatric disorders. This study investigated the effects of cannabis use on treatment retention and abstinence from cocaine among cocaine dependent patients with Attention Deficit Hyperactivity Disorder (ADHD). Cocaine dependent patients diagnosed with current ADHD (DSM-IV, N = 92) aged 25 to 51 participated in a randomized clinical trial of methylphenidate for treatment of ADHD and cocaine dependence in an outpatient setting. The majority of patients (69%) used cannabis during treatment. Results suggest that moderate/intermittent cannabis users had greater retention rates compared to abstainers and consistent users (p = .02). This study is the first to examine concurrent cannabis use in cocaine dependent patients diagnosed with ADHD.
van Rossum, Inge; Boomsma, Maarten; Tenback, Diederik
Research suggests that cannabis use affects negatively on onset and outcome of schizophrenia, but less is known about possible effects in mood disorders. Bipolar in- and outpatients (N = 3459) were enrolled in an observational study. The influence of cannabis exposure on clinical and social...... treatment outcome measures was examined over the course of 1 year, as well as the effects on these associations of third mediating variables. Over 12 months of treatment, cannabis users exhibited less compliance and higher levels of overall illness severity, mania, and psychosis compared with nonusers....... Additionally, cannabis users experienced less satisfaction with life and had a lower probability of having a relationship compared with nonusers. There was little evidence that cannabis-outcome associations were mediated by third variables. An independent impact of cannabis use on psychopathologic outcomes...
Buckner, Julia D; Walukevich, Katherine A; Zvolensky, Michael J; Gallagher, Matthew W
Little empirical work has evaluated why anxious cannabis users are especially vulnerable to poorer cannabis cessation outcomes. Presumably, these individuals rely on cannabis because they have difficulties with emotion regulation and they therefore use cannabis to manage their negative emotions. The current study examined the direct and indirect effects of anxiety severity on a range of cannabis cessation variables among 79 (63.3% non-Hispanic White; 43.0% female) adults with anxiety disorders seeking outpatient treatment for cannabis use disorder. The independent and serial indirect effects of difficulties with emotion regulation and coping motives were examined in relation to the anxiety-cannabis variables. Anxiety severity was directly and robustly related to greater cannabis withdrawal symptom severity, less self-efficacy to refrain from using cannabis in emotionally distressing situations, and more reasons for quitting. Anxiety was indirectly related to cannabis outcomes via the serial effects of emotion regulation and coping motives. These findings document the important role of emotion regulation and coping motives in the relations of anxiety with cannabis cessation variables among dually diagnosed outpatients. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Gazibara, Tatjana; Prpic, Milica; Maric, Gorica; Pekmezovic, Tatjana; Kisic-Tepavcevic, Darija
There are some indices in which legalization of medical cannabis in the Republic of Serbia might be considered. The purpose of this research was to assess knowledge and attitudes towards medical cannabis in an urban adult population. This cross-sectional study was conducted in December 2015 and January 2016. A convenience sample of study participants comprised users of the Community Health Center. A total of 360 adults were invited to participate. Data were collected through an anonymous questionnaire. Most participants (77.1%) answered correctly that cancer was indicative of medical cannabis treatment, while the remaining conditions were less frequently recognized. A total of 42% answered correctly that adverse effects of cannabis were hallucinations and dizziness. Persons who previously used cannabis were more knowledgeable on conditions for medical cannabis treatment (ρ = 0.155; p = 0.006). Study respondents expressed positive attitude towards legalization of medical cannabis (median 5 out of 5) and negative towards legalization of recreational cannabis (median 2 out of 5). In conclusion, the adult population in Belgrade had some knowledge of medical cannabis. The overall attitude of our population regarding legalization of medical cannabis was positive, while the attitude towards legalization of cannabis for recreational purposes was negative.
Erkens, J A; Janse, A F C; Herings, R M C
Since September 2003, cannabis is available for medicinal purposes in Dutch pharmacies to. It was anticipated that the medicinal cannabis use via illegal ways would decrease. The objective of this study was to get insight in the use of medicinal cannabis in daily practise as dispensed by community pharmacies and to characterize the users as well as the symptoms and conditions cannabis is prescribed for.A prospective follow-up study among 200 patients who filled a prescription for medicinal cannabis was performed in the period between September 2003 and January 2004. The patients filled out a structured questionnaire concerning symptoms and conditions and their experience with cannabis. Of all patients, 42% suffered from multiple sclerosis, 11% suffered from rheumatic diseases, and 60% of respondents already used cannabis before the legalization. Cannabis was mainly used for chronic pain and muscle cramp/stiffness.The indication of medicinal cannabis use was in accordance with the labeled indications. However, more than 80% of the patients still obtained cannabis for medicinal purpose from the illegal circuit. Because of the higher prices in pharmacies, ongoing debate on the unproven effectiveness of the drug and the hesitation by physicians to prescribe cannabis. Copyright (c) 2005 John Wiley & Sons, Ltd.
Hamilton, Hayley A; Brands, Bruna; Ialomiteanu, Anca R; Mann, Robert E
To investigate the prevalence of therapeutic cannabis use within a general population sample of adults and to describe various characteristics associated with use. Data were derived from the 2013 and 2014 CAMH Monitor Survey of adults in Ontario, Canada. This repeated cross-sectional survey employed a regionally stratified design and utilized computer-assisted telephone interviewing. Analyses were based on 401 respondents who reported using cannabis. The data indicated that 28.8% of those who used cannabis in the past year self-reported using cannabis for therapeutic purposes. Of therapeutic users, 15.2% reported having medical approval to use cannabis for therapeutic purposes. Cannabis use for therapeutic purposes was associated with more frequent use of cannabis, a moderate to high risk of problematic cannabis use, and a greater likelihood of using prescription opioids for medical purposes. There was little difference in cannabis use for therapeutic purposes according to sex, age, and marital status after adjusting for opioid use and problematic cannabis use. Findings suggest some potential negative consequences of cannabis use for therapeutic purposes; however, further research is needed to better understand the range and patterns of use and their corresponding vulnerabilities.
Andresen, Sven R; Biering-Sørensen, Fin; Hagen, Ellen Merete; Nielsen, Jørgen F; Bach, Flemming W; Finnerup, Nanna B
To evaluate recreational and medical cannabis use in individuals with traumatic spinal cord injury, including reasons and predictors for use, perceived benefits and negative consequences. Cross-sectional survey in Denmark. A 35-item questionnaire was sent to 1,101 patients with spinal cord injury who had been in contact with a rehabilitation centre between 1990 and 2012. A total of 537 participants completed the questionnaire. Of these, 36% had tried cannabis at least once and 9% were current users. Of current users, 79% had started to use cannabis before their spinal cord injury. The main reason for use was pleasure, but 65% used cannabis partly for spinal cord injury-related consequences and 59% reported at least good effect on pain and spasticity. Negative consequences of use were primarily inertia and feeling quiet/subdued. Lower age, living in rural areas/larger cities, tobacco-smoking, high alcohol intake and higher muscle stiffness were significantly associated with cannabis use. Those who had never tried cannabis reported that they would mainly use cannabis to alleviate pain and spasticity if it were legalized. Cannabis use is more frequent among individuals with spinal cord injury in Denmark than among the general population. High muscle stiffness and various demographic characteristics (lower age, living in rural areas/larger cities, tobacco-smoking and high alcohol intake) were associated with cannabis use. Most participants had started using cannabis before their spinal cord injury. There was considerable overlap between recreational and disability-related use.
Hoch, Eva; Bonnetn, Udo; Thomasius, Rainer; Ganzer, Florian; Havemann-Reinecke, Ursula; Preuss, Ulrich W
Cannabis is the most commonly consumed illicit drug around the world; in Germany, about 4.5% of all adults use it each year. Intense cannabis use is associated with health risks. Evidence-based treatments are available for health problems caused by cannabis use. Selective literature review based on a search of the PubMed database, with special emphasis on systematic reviews, meta-analyses, cohort studies, randomized controlled trials (RCTs), case-control studies, and treatment guidelines. The delta-9-tetrahydrocannabinol content of cannabis products is rising around the world as a result of plant breeding, while cannabidiol, in contrast, is often no longer detectable. Various medical conditions can arise acutely after cannabis use, depending on the user's age, dose, frequency, mode and situation of use, and individual disposition; these include panic attacks, psychotic symptoms, deficient attention, impaired concentration, motor incoordination, and nausea. In particular, intense use of high doses of cannabis over many years, and the initiation of cannabis use in adolescence, can be associated with substance dependence (DSM-5; ICD-10), specific withdrawal symptoms, cognitive impairment, affective disorders, psychosis, anxiety disorders, and physical disease outside the brain (mainly respiratory and cardiovascular conditions). At present, the most effective way to treat cannabis dependence involves a combination of motivational encouragement, cognitive behavioral therapy, and contingency management (level 1a evidence). For adolescents, family therapy is also recommended (level 1a evidence). No pharmacological treatments can be recommended to date, as evidence for their efficacy is lacking. Further research is needed to elucidate the causal relationships between intense cannabis use and potential damage to physical and mental health. Health problems due to cannabis use can be effectively treated.
Ruiz-Veguilla, Miguel; Barrigón, María Luisa; Hernández, Laureano; Rubio, José Luis; Gurpegui, Manuel; Sarramea, Fernando; Cervilla, Jorge; Gutiérrez, Blanca; James, Anthony; Ferrin, Maite
This study aimed to explore the associations between daily cannabis use and the specific profiles of subclinical symptoms in a non-clinical population obtained through snowball sampling, taking into account alcohol use, other drug use, social exclusion and age at onset of cannabis use. We included 85 daily cannabis users and 100 non-daily cannabis users. Both the case and the control populations were identified by snowball sampling. Daily cannabis use was associated with more alcohol intake and other drug use, as well as with early onset in the use of cannabis. Daily cannabis use appeared to exert a dose-response effect on first-rank symptoms, mania symptoms and auditory hallucinations, even after adjusting for sex, age, other drug use, social exclusion and age at onset of cannabis use. The paranoid dimension was only associated with the heaviest consumption of cannabis. Initial age of cannabis use modified the effects of daily cannabis use on the first-rank and voices experiences. Daily cannabis use was associated with significantly more first-rank and voices experiences among those subjects who started to use cannabis before 17 years of age. Our study supports the association of psychotic experiences with cannabis use even among non-psychotic subjects. Copyright © 2013 Elsevier Ltd. All rights reserved.
Pacula, Rosalie Liccardo; Jacobson, Mireille; Maksabedian, Ervant J
To describe patterns of cannabis use, the degree of overlap between medicinal and recreational users, and their differential use patterns, modes of consumption and sources of cannabis. An ongoing probability-based internet panel maintained by the market research firm GfK Group. Households in Colorado, Washington, Oregon and New Mexico, USA. A total of 2009 individuals from Washington (n = 787), Oregon (n = 506), Colorado (n = 503) and New Mexico (n = 213). Post stratification sampling weights were provided so that estimates could be made representative of the household population in each of these states. Respondents were aged between 18 and 91 years, with a mean age of 53 years. We compare patterns of cannabis consumption for medicinal and recreational users as well as simultaneous use of alcohol and cannabis. We also examine the extent to which patterns of use differ across states that chose to legalize (Washington and Colorado) and those that did not (New Mexico and Oregon). Rates of life-time medical cannabis use are similar in Colorado and Washington (8.8% and 8.2%) but lower in Oregon and New Mexico (6.5% and 1%). Recreational use is considerably higher than medical use across all states (41%), but highest in Oregon and Washington. Approximately 86% of people who report ever using cannabis for medicinal purposes also use it recreationally. Medical users are more likely to vaporize and consume edibles and report a higher amount (in grams) consumed, and spend more money per month than recreational users. Individuals who use cannabis do not commonly use it with alcohol, irrespective of whether they are consuming cannabis recreationally or medically. Fewer than one in five recreational users report simultaneous use of alcohol and cannabis most or all of the time and fewer than 3% of medicinal users report frequent simultaneous use of alcohol and cannabis. In the United States, the degree of overlap between medicinal and recreational cannabis users is 86
Franklyn, Alexandra M; Eibl, Joseph K; Gauthier, Graham J; Marsh, David C
With the Canadian government legalizing cannabis in the year 2018, the potential harms to certain populations-including those with opioid use disorder-must be investigated. Cannabis is one of the most commonly used substances by patients who are engaged in medication-assisted treatment for opioid use disorder, the effects of which are largely unknown. In this study, we examine the impact of baseline and ongoing cannabis use, and whether these are impacted differentially by gender. We conducted a retrospective cohort study using anonymized electronic medical records from 58 clinics offering opioid agonist therapy in Ontario, Canada. One-year treatment retention was the primary outcome of interest and was measured for patients who did and did not have a cannabis positive urine sample in their first month of treatment, and as a function of the proportion of cannabis-positive urine samples throughout treatment. Our cohort consisted of 644 patients, 328 of which were considered baseline cannabis users and 256 considered heavy users. Patients with baseline cannabis use and heavy cannabis use were at increased risk of dropout (38.9% and 48.1%, respectively). When evaluating these trends by gender, only female baseline users and male heavy users are at increased risk of premature dropout. Both baseline and heavy cannabis use are predictive of decreased treatment retention, and differences do exist between genders. With cannabis being legalized in the near future, physicians should closely monitor cannabis-using patients and provide education surrounding the potential harms of using cannabis while receiving treatment for opioid use disorder.
Shevlin, Mark; McElroy, Eoin; Murphy, Jamie
Purpose: While research has consistently identified an association between cannabis use and psychosis, few studies have examined this relationship in a polydrug context (i.e. combining cannabis with other illicit substances). The paper aims to discuss this issue. Design/methodology/approach: The ......Purpose: While research has consistently identified an association between cannabis use and psychosis, few studies have examined this relationship in a polydrug context (i.e. combining cannabis with other illicit substances). The paper aims to discuss this issue. Design....../methodology/approach: The present study sought to examine the association between recreational drug use (cannabis only vs polydrug) and psychotic disorders. Analysis was conducted on a large, representative survey of young Danish people aged 24 (n=4,718). Participants completed self-report measures of lifetime drug use...... and this information was linked to the Danish psychiatric registry system. Findings: Multivariate binary logistic regression analysis was used to examine the association between drug use (no drug use, cannabis only, cannabis and other drug) and ICD-10 psychotic disorders, while controlling for gender and parental...
Khadrawy, Yasser A; Sawie, Hussein G; Abdel-Salam, Omar M E; Hosny, Eman N
Cannabis sativa is one of the most widely recreational drugs and its use is more prevalent among depressed patients. Some studies reported that Cannabis has antidepressant effects while others showed increased depressive symptoms in Cannabis users. Therefore, the present study aims to investigate the effect of Cannabis extract on the depressive-like rats. Twenty four rats were divided into: control, rat model of depression induced by reserpine and depressive-like rats treated with Cannabis sativa extract (10mg/kg expressed as Δ9-tetrahydrocannabinol). The depressive-like rats showed a severe decrease in motor activity as assessed by open field test (OFT). This was accompanied by a decrease in monoamine levels and a significant increase in acetylcholinesterase activity in the cortex and hippocampus. Na + ,K + -ATPase activity increased in the cortex and decreased in the hippocampus of rat model. In addition, a state of oxidative stress was evident in the two brain regions. This was indicated from the significant increase in the levels of lipid peroxidation and nitric oxide. No signs of improvement were observed in the behavioral and neurochemical analyses in the depressive-like rats treated with Cannabis extract. Furthermore, Cannabis extract exacerbated the lipid peroxidation in the cortex and hippocampus. According to the present findings, it could be concluded that Cannabis sativa aggravates the motor deficits and neurochemical changes induced in the cortex and hippocampus of rat model of depression. Therefore, the obtained results could explain the reported increase in the depressive symptoms and memory impairment among Cannabis users. Copyright © 2017 Elsevier B.V. All rights reserved.
Longitudinal studies of the association between use of cannabis and later psychosis or schizophrenia were reviewed. Studies included were studies in the general population and in conscripts, using information from interviews about use of cannabis and register-based follow-up in psychiatric case......-registers or in personal interviews. There was a consistent finding that use of cannabis was associated with an increased risk of later psychosis with an odds ratio of approximately 2, when adjusted for predisposition to mental illness and socio-demographic risk factors....
Brancheau, Daniel; Blanco, Jessica; Gholkar, Gunjan; Patel, Brijesh; Machado, Christian
Cannabis or marijuana is the most used recreational, and until recently illegal, drug in the United States. Although cannabis has medicinal use, its consumption has been linked to motor vehicle accidents in dose dependent fashion. Marijuana and other cannabinoids produce a multitude of effects on the human body that may result in these motor vehicle accidents. Some of the effects that marijuana has been known to cause include altered sensorium, diminished reflexes, and increased vagal tone. We present a case of cannabis induced asystole from hypervagotonia. Copyright © 2016 Elsevier Inc. All rights reserved.
Full Text Available BACKGROUND: The aim of this study was to describe the patterns of cannabis use and the associated benefits reported by patients with fibromyalgia (FM who were consumers of this drug. In addition, the quality of life of FM patients who consumed cannabis was compared with FM subjects who were not cannabis users. METHODS: Information on medicinal cannabis use was recorded on a specific questionnaire as well as perceived benefits of cannabis on a range of symptoms using standard 100-mm visual analogue scales (VAS. Cannabis users and non-users completed the Fibromyalgia Impact Questionnaire (FIQ, the Pittsburgh Sleep Quality Index (PSQI and the Short Form 36 Health Survey (SF-36. RESULTS: Twenty-eight FM patients who were cannabis users and 28 non-users were included in the study. Demographics and clinical variables were similar in both groups. Cannabis users referred different duration of drug consumption; the route of administration was smoking (54%, oral (46% and combined (43%. The amount and frequency of cannabis use were also different among patients. After 2 hours of cannabis use, VAS scores showed a statistically significant (p<0.001 reduction of pain and stiffness, enhancement of relaxation, and an increase in somnolence and feeling of well being. The mental health component summary score of the SF-36 was significantly higher (p<0.05 in cannabis users than in non-users. No significant differences were found in the other SF-36 domains, in the FIQ and the PSQI. CONCLUSIONS: The use of cannabis was associated with beneficial effects on some FM symptoms. Further studies on the usefulness of cannabinoids in FM patients as well as cannabinoid system involvement in the pathophysiology of this condition are warranted.
Palamar, Joseph J.; Ompad, Danielle C.; Petkova, Eva
Background Support for cannabis (“marijuana”) legalization is increasing in the United States (US). Use was recently legalized in two states and in Uruguay, and other states and countries are expected to follow suit. This study examined intentions to use among US high school seniors if cannabis were to become legally available. Methods Data from the last five cohorts (2007–2011) of high school seniors in Monitoring the Future, an annual nationally representative survey of students in the US were utilized. Data were analyzed separately for the 6,116 seniors who reported no lifetime use of cannabis and the 3,828 seniors who reported lifetime use (weighted Ns). We examined whether demographic characteristics, substance use and perceived friend disapproval towards cannabis use were associated with 1) intention to try cannabis among non-lifetime users, and 2) intention to use cannabis as often or more often among lifetime users, if cannabis was legal to use. Results Ten percent of non-cannabis-using students reported intent to initiate use if legal and this would constitute a 5.6% absolute increase in lifetime prevalence of cannabis use in this age group from 45.6% (95% CI=46.6, 44.6) to 51.2% (95% CI=50.2, 52.2). Eighteen percent of lifetime users reported intent to use cannabis more often if it was legal. Odds for intention to use outcomes increased among groups already at high risk for use (e.g., males, whites, cigarette smokers) and odds were reduced when friends disapproved of use. However, large proportions of subgroups of students normally at low risk for use (e.g., non-cigarette-smokers, religious students, those with friends who disapprove of use) reported intention to use if legal. Recent use was also a risk factor for reporting intention to use as often or more often. Conclusion Prevalence of cannabis use is expected to increase if cannabis is legal to use and legally available. PMID:24589410
Palamar, Joseph J; Ompad, Danielle C; Petkova, Eva
Support for cannabis ("marijuana") legalization is increasing in the United States (US). Use was recently legalized in two states and in Uruguay, and other states and countries are expected to follow suit. This study examined intentions to use among US high school seniors if cannabis were to become legally available. Data from the last five cohorts (2007-2011) of high school seniors in Monitoring the Future, an annual nationally representative survey of students in the US were utilized. Data were analyzed separately for the 6116 seniors who reported no lifetime use of cannabis and the 3829 seniors who reported lifetime use (weighted Ns). We examined whether demographic characteristics, substance use and perceived friend disapproval towards cannabis use were associated with (1) intention to try cannabis among non-lifetime users, and (2) intention to use cannabis as often or more often among lifetime users, if cannabis was legal to use. Ten percent of non-cannabis-using students reported intent to initiate use if legal and this would be consistent with a 5.6% absolute increase in lifetime prevalence of cannabis use in this age group from 45.6% (95% CI=44.6, 46.6) to 51.2% (95% CI=50.2, 52.2). Eighteen percent of lifetime users reported intent to use cannabis more often if it was legal. Odds for intention to use outcomes increased among groups already at high risk for use (e.g., males, whites, cigarette smokers) and odds were reduced when friends disapproved of use. However, large proportions of subgroups of students normally at low risk for use (e.g., non-cigarette-smokers, religious students, those with friends who disapprove of use) reported intention to use if legal. Recent use was also a risk factor for reporting intention to use as often or more often. Prevalence of cannabis use is expected to increase if cannabis is legal to use and legally available. Copyright © 2014 Elsevier B.V. All rights reserved.
Cuttler, Carrie; Spradlin, Alexander
We created the Daily Sessions, Frequency, Age of Onset, and Quantity of Cannabis Use Inventory (DFAQ-CU) because the current lack of psychometrically sound inventories for measuring these dimensions of cannabis use has impeded research on the effects of cannabis in humans. A sample of 2,062 cannabis users completed the DFAQ-CU and was used to assess the DFAQ-CU's factor structure and reliability. To assess validity, a subsample of 645 participants completed additional measures of cannabis dependence and problems (Marijuana Smoking History Questionnaire [MSHQ], Timeline Followback [TLFB], Cannabis Abuse Screening Test [CAST], Cannabis Use Disorders Identification Test Revised [CUDIT-R], Cannabis Use Problems Identification Test [CUPIT], and Alcohol Use Disorder Identification Test [AUDIT]). A six-factor structure was revealed, with factors measuring: daily sessions, frequency, age of onset, marijuana quantity, cannabis concentrate quantity, and edibles quantity. The factors were reliable, with Cronbach's alpha coefficients ranging from .69 (daily sessions) to .95 (frequency). Results further provided evidence for the factors' convergent (MSHQ, TLFB), predictive (CAST, CUDIT-R, CUPIT), and discriminant validity (AUDIT). The DFAQ-CU is the first psychometrically sound inventory for measuring frequency, age of onset, and quantity of cannabis use. It contains pictures of marijuana to facilitate the measurement of quantity of marijuana used, as well as questions to assess the use of different forms of cannabis (e.g., concentrates, edibles), methods of administering cannabis (e.g., joints, hand pipes, vaporizers), and typical THC levels. As such, the DFAQ-CU should help facilitate research on frequency, quantity, and age of onset of cannabis use.
Full Text Available We created the Daily Sessions, Frequency, Age of Onset, and Quantity of Cannabis Use Inventory (DFAQ-CU because the current lack of psychometrically sound inventories for measuring these dimensions of cannabis use has impeded research on the effects of cannabis in humans.A sample of 2,062 cannabis users completed the DFAQ-CU and was used to assess the DFAQ-CU's factor structure and reliability. To assess validity, a subsample of 645 participants completed additional measures of cannabis dependence and problems (Marijuana Smoking History Questionnaire [MSHQ], Timeline Followback [TLFB], Cannabis Abuse Screening Test [CAST], Cannabis Use Disorders Identification Test Revised [CUDIT-R], Cannabis Use Problems Identification Test [CUPIT], and Alcohol Use Disorder Identification Test [AUDIT].A six-factor structure was revealed, with factors measuring: daily sessions, frequency, age of onset, marijuana quantity, cannabis concentrate quantity, and edibles quantity. The factors were reliable, with Cronbach's alpha coefficients ranging from .69 (daily sessions to .95 (frequency. Results further provided evidence for the factors' convergent (MSHQ, TLFB, predictive (CAST, CUDIT-R, CUPIT, and discriminant validity (AUDIT.The DFAQ-CU is the first psychometrically sound inventory for measuring frequency, age of onset, and quantity of cannabis use. It contains pictures of marijuana to facilitate the measurement of quantity of marijuana used, as well as questions to assess the use of different forms of cannabis (e.g., concentrates, edibles, methods of administering cannabis (e.g., joints, hand pipes, vaporizers, and typical THC levels. As such, the DFAQ-CU should help facilitate research on frequency, quantity, and age of onset of cannabis use.
Loflin, Mallory; Earleywine, Mitch; De Leo, Joseph; Hobkirk, Andrea
The current study examined the association between subtypes of attention-deficit/hyperactivity disorder (ADHD) and cannabis use within a sample of 2811 current users. Data were collected in 2012 from a national U.S. survey of cannabis users. A series of logistic regression equations and chi-squares were assessed for proportional differences between users. When asked about the ADHD symptoms they have experienced when not using cannabis, a higher proportion of daily users met symptom criteria for an ADHD diagnoses of the subtypes that include hyperactive-impulsive symptoms than the inattentive subtype. For nondaily users, the proportions of users meeting symptom criteria did not differ by subtype. These results have implications for identifying which individuals with ADHD might be more likely to self-medicate using cannabis. Furthermore, these findings indirectly support research linking relevant cannabinoid receptors to regulatory control.
Skyler G. Shollenbarger
Conclusions: Consistent with prior findings, cannabis use was associated with reduced frontolimbic WM integrity. WM integrity was also moderated by FAAH genotype, in that cannabis-using FAAH C/C carriers and A carrying controls had reduced WM integrity compared to control C/C carriers. Observed frontolimbic white matter abnormalities were linked with increased depressive and apathy symptoms in the cannabis users.
Blankers, Matthijs; Frijns, Tom; Belackova, Vendula; Rossi, Carla; Svensson, Bengt; Trautmann, Franz; van Laar, Margriet
Cannabis is Europe's most commonly used illicit drug. Some users do not develop dependence or other problems, whereas others do. Many factors are associated with the occurrence of cannabis-related disorders. This makes it difficult to identify key risk factors and markers to profile at-risk cannabis
Jager, Gerry; Kahn, Rene S; Van Den Brink, Wim; Van Ree, Jan M; Ramsey, Nick F
Excessive use of cannabis may have long-term effects on cognitive abilities. Mild impairments have been found in several cognitive domains, particularly in memory and attention. It is not clear, however, whether these effects also occur with moderate, recreational use of cannabis. Furthermore, little is known about underlying brain correlates. The aim of this study is to assess brain function in frequent but relatively moderate cannabis users in the domains of working memory and selective attention. Functional magnetic resonance imaging was used to examine verbal working memory and visuo-auditory selective attention in ten frequent cannabis users (after 1 week of abstinence) and ten non-using healthy controls. Groups were similar in age, gender and estimated IQ. Cannabis users and controls performed equally well during the working memory task and the selective attention task. Furthermore, cannabis users did not differ from controls in terms of overall patterns of brain activity in the regions involved in these cognitive functions. However, for working memory, a more specific region-of-interest analysis showed that, in comparison to the controls, cannabis users displayed a significant alteration in brain activity in the left superior parietal cortex. No evidence was found for long-term deficits in working memory and selective attention in frequent cannabis users after 1 week of abstinence. Nonetheless, frequent cannabis use may affect brain function, as indicated by altered neurophysiological dynamics in the left superior parietal cortex during working memory processing.
... passed the Boggs Act, which included Cannabis with narcotic drugs for the first time. Under the Controlled Substances ... and Alternative Medicine (OCCAM). Health care professionals who offer alternative cancer therapies submit their patients’ medical records ...
Hollister, Leo E.
Literature pertaining to the effects of cannabis use and health which has been published during the past 11 years has been reviewed. Many older concerns about adverse effects on health (chromosomal damage, 'cannabinol psychosis', endocrine abnormalities, cardiac events, impaired immunity) no longer seem to elicit much interest. Continuing concerns about the adverse cognitive effects of chronic use indicate that these can be demonstrated by proper testing; some studies suggest that they may be long-lasting. Although cannabis does not produce a specific psychosis, the possibility exists that it may exacerbate schizophrenia in persons predisposed to that disorder. However, evidence from retrospective surveys must always be questioned. Tolerance and dependence have occurred in man, confirming previous findings in many other species. Addiction tends to be mild and is probably less severe than with other social drugs. Driving under the influence of cannabis is impaired acutely; how long such impairments last is still unknown. More exacting tasks, such as flying an airplane, may be impaired for as long as 24 hours. While there is no doubt that marijuana smoke contains carcinogens, an increase in cancer among users has thus far been anecdotal. Because of the long latent period between cancer induction and initiation of cigarette smoking, the full story is yet to be told. Marijuana use during pregnancy is not advised although the consequences are usually not greater than those of smoking cigarettes, and far less than those from alcohol use. Whether smoked marijuana should become a therapeutic agent requires a cost-benefit analysis of the potential benefits versus the adverse effects of such use as we now know them.
Saugy, M; Avois, L; Saudan, C; Robinson, N; Giroud, C; Mangin, P; Dvorak, J
Cannabis is on the list of prohibited substances in the practice of sport, although its performance enhancing effect has not yet been proved. Its popularity among the younger generations as a social drug puts cannabis at the top of the list of compounds detected by the anti-doping laboratories accredited by the World Anti-Doping Agency worldwide. The management of the results of urine analysis is quite difficult for the medical and disciplinary committees not only because of the social use of the substance, but also because of the interpretation of the analytical data from urine samples. This paper gives an overview of what is presently known about cannabis in relation with the practice of sport. Review of literature on the cannabis and exercise, its effect in the body, and the problems with interpretation of results when it is detected in urine. The paper outlines the major effects of cannabis in the context of its social use and its use for sport activities. The difficulties in the interpretation of urine sample analysis results because of the protracted excretion time of the main metabolite, long after the intake, are described. There is an urgent need for sport authorities to take measures necessary to avoid players misusing cannabis.
Full Text Available Abstract Background Epidemiological studies show wide variability in the occurrence of cannabis smoking and related disorders across countries. This study aims to estimate cross-national variation in cannabis users' experience of clinically significant cannabis-related problems in three countries of the Americas, with a focus on cannabis users who may have tried alcohol or tobacco, but who have not used cocaine, heroin, LSD, or other internationally regulated drugs. Methods Data are from the World Mental Health Surveys Initiative and the National Latino and Asian American Study, with probability samples in Mexico (n = 4426, Colombia (n = 5,782 and the United States (USA; n = 8,228. The samples included 212 'cannabis only' users in Mexico, 260 in Colombia and 1,724 in the USA. Conditional GLM with GEE and 'exact' methods were used to estimate variation in the occurrence of clinically significant problems in cannabis only (CO users across these surveyed populations. Results The experience of cannabis-related problems was quite infrequent among CO users in these countries, with weighted frequencies ranging from 1% to 5% across survey populations, and with no appreciable cross-national variation in general. CO users in Colombia proved to be an exception. As compared to CO users in the USA, the Colombia smokers were more likely to have experienced cannabis-associated 'social problems' (odds ratio, OR = 3.0; 95% CI = 1.4, 6.3; p = 0.004 and 'legal problems' (OR = 9.7; 95% CI = 2.7, 35.2; p = 0.001. Conclusions This study's most remarkable finding may be the similarity in occurrence of cannabis-related problems in this cross-national comparison within the Americas. Wide cross-national variations in estimated population-level cumulative incidence of cannabis use disorders may be traced to large differences in cannabis smoking prevalence, rather than qualitative differences in cannabis experiences. More research is needed to identify conditions that
Capler, Rielle; Walsh, Zach; Crosby, Kim; Belle-Isle, Lynne; Holtzman, Susan; Lucas, Philippe; Callaway, Robert
In 2001, Canada established a federal program for cannabis for therapeutic purposes (CTP). Medical cannabis dispensaries (dispensaries) are widely accessed as a source of CTP despite storefront sales of cannabis being illegal. The discrepancy between legal status and social practice has fuelled active debate regarding the role of dispensaries. The present study aims to inform this debate by analysing CTP user experiences with different CTP sources, and comparing dispensary users to those accessing CTP from other sources. We compared sociodemographic characteristics, health related factors and patterns of cannabis use of 445 respondents, 215 who accessed CTP from dispensaries with 230 who accessed other sources. We compared patients' ratings of CTP sources (dispensaries, Health Canada's supplier, self-production, other producer, friend or acquaintance, street dealer) for quality and availability of product, safety and efficiency of access, cost, and feeling respected while accessing. Patients using dispensaries were older, more likely to have arthritis and HIV/AIDS, and less likely to have mental health conditions than those not using dispensaries. Those accessing dispensaries used larger quantities of cannabis, placed greater value on access to specific strains, and were more likely to have legal authorization for CTP. Dispensaries were rated equally to or more favourably than other sources of CTP for quality, safety, availability, efficiency and feeling respected, and less favourably than self-production and other producer for cost. Given the high endorsement of dispensaries by patients, future regulations should consider including dispensaries as a source of CTP and address known barriers to access such as cost and health care provider support. Further research should assess the impact of the addition of licensed producers on the role and perceived value of dispensaries within the Canadian medical cannabis system. Copyright © 2017 Elsevier B.V. All rights
Huizink, Anja C.; Ferdinand, Robert F.; Ormel, Johan; Verhulst, Frank C.
Aims To identify early onset cannabis users by measuring basal hypothalamic-pituitary-adrenal (HPA) axis activity, which may be a risk factor for early onset substance use when showing low activity. Design In a prospective cohort study, adolescents who initiated cannabis use at an early age (9-12
Lorenzetti, V; Batalla, A.; Cousijn, J.
Cannabis use disorders (CUDs) affect 13.1 million individuals worldwide. Brain morphology specific to CUDs may mediate the adverse behavioral outcomes of CUDs. We reviewed findings from 20 human neuroimaging studies on grey and white matter morphology in cannabis users that specifically included CUD
Huizink, Anja C.; Ferdinand, Robert F.; Ormel, Johan; Verhulst, Frank C.
Aims To identify early onset cannabis users by measuring basal hypothalamic-pituitary-adrenal (HPA) axis activity, which may be a risk factor for early onset substance use when showing low activity. Design In a prospective cohort study, adolescents who initiated cannabis use at an early age (9-12
Panlilio, Leigh V.; Justinova, Zuzana; Trigo, Jose M.; Le Foll, Bernard
Cannabis use has been increasingly accepted legally and in public opinion. However, cannabis has the potential to produce adverse physical and mental health effects and can result in cannabis use disorder (CUD) in a substantial percentage of both occasional and daily cannabis users. Many people have difficulty discontinuing use. Therefore, it would be beneficial to develop safe and effective medications for treating CUD. To achieve this, methods have been developed for screening and evaluating potential medications using animal models and controlled experimental protocols in human volunteers. In this chapter we describe: 1) animal models available for assessing the effect of potential medications on specific aspects of CUD; 2) the main findings obtained so far with these animal models; 3) the approaches used to assess potential medications in humans in laboratory experiments and clinical trials; and 4) the effectiveness of several potential pharmacotherapies on the particular aspects of CUD modeled in these human studies. PMID:27055612
Broséus, J.; Anglada, F.; Esseiva, P.
Cannabis cultivation in order to produce drugs is forbidden in Switzerland. Thus, law enforcement authorities regularly ask forensic laboratories to determinate cannabis plant's chemotype from seized material in order to ascertain that the plantation is legal or not. As required by the EU official analysis protocol the THC rate of cannabis is measured from the flowers at maturity. When laboratories are confronted to seedlings, they have to lead the plant to maturity, meaning a time consumi...
Lamy, Francois R; Daniulaityte, Raminta; Sheth, Amit; Nahhas, Ramzi W; Martins, Silvia S; Boyer, Edward W; Carlson, Robert G
Several states in the U.S. have legalized cannabis for recreational or medical uses. In this context, cannabis edibles have drawn considerable attention after adverse effects were reported. This paper investigates Twitter users' perceptions concerning edibles and evaluates the association edibles-related tweeting activity and local cannabis legislation. Tweets were collected between May 1 and July 31, 2015, using Twitter API and filtered through the eDrugTrends/Twitris platform. A random sample of geolocated tweets was manually coded to evaluate Twitter users' perceptions regarding edibles. Raw state proportions of Twitter users mentioning edibles were ajusted relative to the total number of Twitter users per state. Differences in adjusted proportions of Twitter users mentioning edibles between states with different cannabis legislation status were assesed via a permutation test. We collected 100,182 tweets mentioning cannabis edibles with 26.9% (n=26,975) containing state-level geolocation. Adjusted percentages of geolocated Twitter users posting about edibles were significantly greater in states that allow recreational and/or medical use of cannabis. The differences were statistically significant. Overall, cannabis edibles were generally positively perceived among Twitter users despite some negative tweets expressing the unreliability of edible consumption linked to variability in effect intensity and duration. Our findings suggest that Twitter data analysis is an important tool for epidemiological monitoring of emerging drug use practices and trends. Results tend to indicate greater tweeting activity about cannabis edibles in states where medical THC and/or recreational use are legal. Although the majority of tweets conveyed positive attitudes about cannabis edibles, analysis of experiences expressed in negative tweets confirms the potential adverse effects of edibles and calls for educating edibles-naïve users, improving edibles labeling, and testing their THC
Jarvinen, Margaretha; Demant, Jakob Johan
This paper analyses ‘techniques of neutralisation’ among young people discussing cannabis in focus group interviews. The paper is based on data from focus group interviews with young Danes followed from when they were 14–15 years old in 2004 until they were 18–19 years old in 2008. In this period......, the participants’ attitudes towards cannabis undergo a radical change from being negative and sceptical into being predominantly positive and accepting; a change we describe as a ‘normalisation’ of cannabis use. Four techniques of neutralisation are identified in this process. First, the participants redefine...... the setting of cannabis use, simultaneously creating a new type of togetherness: relaxed social intoxication. Second, the effects of cannabis use are transformed from being ‘strange’ and ‘unpredictable’ to being ‘controllable’ by the individual user. Third, participants change their classification of cannabis...
Mokrysz, C; Landy, R; Gage, SH; Munafò, MR; Roiser, JP; Curran, HV
There is much debate about the impact of adolescent cannabis use on intellectual and educational outcomes. We investigated associations between adolescent cannabis use and IQ and educational attainment in a sample of 2235 teenagers from the Avon Longitudinal Study of Parents and Children. By the age of 15, 24% reported having tried cannabis at least once. A series of nested linear regressions was employed, adjusted hierarchically by pre-exposure ability and potential confounds (e.g. cigarette and alcohol use, childhood mental-health symptoms and behavioural problems), to test the relationships between cumulative cannabis use and IQ at the age of 15 and educational performance at the age of 16. After full adjustment, those who had used cannabis ⩾50 times did not differ from never-users on either IQ or educational performance. Adjusting for group differences in cigarette smoking dramatically attenuated the associations between cannabis use and both outcomes, and further analyses demonstrated robust associations between cigarette use and educational outcomes, even with cannabis users excluded. These findings suggest that adolescent cannabis use is not associated with IQ or educational performance once adjustment is made for potential confounds, in particular adolescent cigarette use. Modest cannabis use in teenagers may have less cognitive impact than epidemiological surveys of older cohorts have previously suggested. PMID:26739345
Pearson-Dennett, Verity; Todd, Gabrielle; Wilcox, Robert A; Vogel, Adam P; White, Jason M; Thewlis, Dominic
Despite evidence that cannabinoid receptors are located in movement-related brain regions (e.g., basal ganglia, cerebral cortex, and cerebellum), and that chronic cannabis use is associated with structural and functional brain changes, little is known about the long-term effect of cannabis use on human movement. The aim of the current study was to investigate balance and walking gait in adults with a history of cannabis use. We hypothesised that cannabis use is associated with subtle changes in gait and balance that are insufficient in magnitude for detection in a clinical setting. Cannabis users (n=22, 24±6years) and non-drug using controls (n=22, 25±8years) completed screening tests, a gait and balance test (with a motion capture system and in-built force platforms), and a clinical neurological examination of movement. Compared to controls, cannabis users exhibited significantly greater peak angular velocity of the knee (396±30 versus 426±50°/second, P=0.039), greater peak elbow flexion (53±12 versus 57±7°, P=0.038) and elbow range of motion (33±13 versus 36±10°, P=0.044), and reduced shoulder flexion (41±19 versus 26±16°, P=0.007) during walking gait. However, balance and neurological parameters did not significantly differ between the groups. The results suggest that history of cannabis use is associated with long-lasting changes in open-chain elements of walking gait, but the magnitude of change is not clinically detectable. Further research is required to investigate if the subtle gait changes observed in this population become more apparent with aging and increased cannabis use. Copyright © 2017 Elsevier B.V. All rights reserved.
Jacobus, Joanna; Tapert, Susan F
This article reviews neuroimaging, neurocognitive, and preclinical findings on the effects of cannabis on the adolescent brain. Marijuana is the second most widely used intoxicant in adolescence, and teens who engage in heavy marijuana use often show disadvantages in neurocognitive performance, macrostructural and microstructural brain development, and alterations in brain functioning. It remains unclear whether such disadvantages reflect pre-existing differences that lead to increased substances use and further changes in brain architecture and behavioral outcomes. Future work should focus on prospective investigations to help disentangle dose-dependent effects from pre-existing effects, and to better understand the interactive relationships with other commonly abused substances (e.g., alcohol) to better understand the role of regular cannabis use on neurodevelopmental trajectories.
Jacobus, Joanna; Tapert, Susan F.
This article reviews neuroimaging, neurocognitive, and preclinical findings on the effects of cannabis on the adolescent brain. Marijuana is the second most widely used intoxicant in adolescence, and teens who engage in heavy marijuana use often show disadvantages in neurocognitive performance, macrostructural and microstructural brain development, and alterations in brain functioning. It remains unclear whether such disadvantages reflect pre-existing differences that lead to increased substances use and further changes in brain architecture and behavioral outcomes. Future work should focus on prospective investigations to help disentangle dose-dependent effects from pre-existing effects, and to better understand the interactive relationships with other commonly abused substances (e.g., alcohol) to better understand the role of regular cannabis use on neurodevelopmental trajectories. PMID:23829363
van Ours, J.C.
This paper uses information about prime age individuals living in Amsterdam, to study whether the use of alcohol, or tobacco stimulates the use cannabis, i.e. whether alcohol or cannabis are stepping stones for cannabis.The special element of the study is that it concerns the use in an environment
van Gastel, W.A.
Cannabis use has been implicated as a risk factor for mental health problems, (subclinical) psychotic symptoms in particular. If cannabis use was a cause of these problems, cessation would lead to improved public mental health. If cannabis use was a mere consequence of a predisposition for mental
Kindred, John H; Li, Kaigang; Ketelhut, Nathaniel B; Proessl, Felix; Fling, Brett W; Honce, Justin M; Shaffer, William R; Rudroff, Thorsten
Cannabis has been used for medicinal purpose for thousands of years; however the positive and negative effects of cannabis use in Parkinson's disease (PD) and Multiple Sclerosis (MS) are mostly unknown. Our aim was to assess cannabis use in PD and MS and compare results of self-reported assessments of neurological disability between current cannabis users and non-users. An anonymous web-based survey was hosted on the Michael J. Fox Foundation and the National Multiple Sclerosis Society webpages from 15 February to 15 October 2016. The survey collected demographic and cannabis use information, and used standardized questionnaires to assess neurological function, fatigue, balance, and physical activity participation. Analysis of variance and chi-square tests were used for the analysis. The survey was viewed 801 times, and 595 participants were in the final data set. Seventy-six percent and 24% of the respondents reported PD and MS respectively. Current users reported high efficacy of cannabis, 6.4 (SD 1.8) on a scale from 0 to 7 and 59% reported reducing prescription medication since beginning cannabis use. Current cannabis users were younger and less likely to be classified as obese (P Cannabis users reported lower levels of disability, specifically in domains of mood, memory, and fatigue (PCannabis may have positive impacts on mood, memory, fatigue, and obesity status in people with PD and MS. Further studies using clinically and longitudinally assessed measurements of these domains are needed to establish if these associations are causal and determine the long-term benefits and consequences of cannabis use in people with PD and MS. Copyright © 2017 Elsevier Ltd. All rights reserved.
Smith, Matthew J; Alden, Eva C; Herrold, Amy A; Roberts, Andrea; Stern, Dan; Jones, Joseph; Barnes, Allan; O'Connor, Kailyn P; Huestis, Marilyn A; Breiter, Hans C
Research typically characterizes cannabis use by self-report of cannabis intake frequency. In an effort to better understand relationships between measures of cannabis use, we evaluated if Δ-9-tetrahydrocannabinol (THC) and metabolite concentrations (biometrics) were associated with a calibrated timeline followback (TLFB) assessment of cannabis use. Participants were 35 young adult male cannabis users who completed a calibrated TLFB measure of cannabis use over the past 30 days, including time of last use. The calibration required participants handling four plastic bags of a cannabis substitute (0.25, 0.5, 1.0, and 3.5 grams) to quantify cannabis consumed. Participants provided blood and urine samples for analysis of THC and metabolites, at two independent laboratories. Participants abstained from cannabis use on the day of sample collection. We tested Pearson correlations between the calibrated TLFB measures and cannabis biometrics. Strong correlations were seen between urine and blood biometrics (all r > .73, all p biometric, including urine 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH) and blood THC, 11-hydroxy-THC (11-OH-THC), THCCOOH, THCCOOH-glucuronide (times of use: r > .48-.61, all p .40-.49, all p biometrics. The calibration of cannabis intake in grams was associated with each biometric, although the simple TLFB measure of times of use produced the strongest relationships with all five biometrics. These findings suggest that combined self-report and biometric data together convey the complexity of cannabis use, but allow that either the use of calibrated TLFB measures or biometrics may be sufficient for assessment of cannabis use in research.
Carliner, Hannah; Brown, Qiana L; Sarvet, Aaron L; Hasin, Deborah S
Cannabis is widely used among adolescents and adults. In the U.S., marijuana laws have been changing, and Americans increasingly favor legalizing cannabis for medical and recreational uses. While some can use cannabis without harm, others experience adverse consequences. The objective of this review is to summarize information on the legal status of cannabis, perceptions regarding cannabis, prevalence and time trends in use and related adverse consequences, and evidence on the relationship of state medical (MML) and recreational (RML) marijuana laws to use and attitudes. Twenty-nine states now have MMLs, and eight of these have RMLs. Since the early 2000s, adult and adolescent perception of cannabis use as risky has decreased. Over the same time, the prevalence of adolescent cannabis use has changed little. However, adult cannabis use, disorders, and related consequences have increased. Multiple nationally representative studies indicate that MMLs have had little effect on cannabis use among adolescents. However, while MML effects have been less studied in adults, available evidence suggests that MMLs increase use and cannabis use disorders in adults. While data are not yet available to evaluate the effect of RMLs, they are likely to lower price, increase availability, and thereby increase cannabis use. More permissive marijuana laws may accomplish social justice aims (e.g., reduce racial disparities in law enforcement) and generate tax revenues. However, such laws may increase cannabis-related adverse health and psychosocial consequences by increasing the population of users. Dissemination of balanced information about the potential health harms of cannabis use is needed. Copyright © 2017. Published by Elsevier Inc.
Walsh, Zach; Callaway, Robert; Belle-Isle, Lynne; Capler, Rielle; Kay, Robert; Lucas, Philippe; Holtzman, Susan
The authorized and unauthorized use of cannabis for therapeutic purposes (CTP) has increased dramatically in recent years, and physicians have called for further research to better clarify the parameters of effective and appropriate use. We report findings from a large cross-sectional study of the use of CTP in Canada and compare use across medical conditions and across authorized and unauthorized users. We examined cannabis use history, medical conditions and symptoms, patterns of current use of CTP, modes of access and perceived effectiveness among 628 self-selected Canadians consumers of CTP. Participants were recruited from medical cannabis dispensaries and from organizations that assist users of CTP. Patients reported using cannabis to treat multiple symptoms, with sleep, pain, and anxiety being the most common. Cannabis was perceived to provide effective symptoms relief across medical conditions. Patterns of use were also consistent across medical conditions. Notable differences were observed with regard to modes of access. Across medical conditions respondents reported using cannabis to effectively address diverse symptoms. Results indicate a substantial disconnect between the therapeutic use of cannabis and research on the risks and benefits of such use; particularly with regard to the anxiolytic and sedative use of cannabis. Authorized and unauthorized users exhibited few meaningful differences with regard to medical conditions and patterns of use, but faced substantial differences regarding access. Copyright © 2013 Elsevier B.V. All rights reserved.
Cuypers, Eva; Vanhove, Wouter; Gotink, Joachim; Bonneure, Arne; Van Damme, Patrick; Tytgat, Jan
Cannabis (Cannabis spp.) use and cultivation continue to increase in many (European) countries. The illicit indoor cannabis plantations that supply Belgian and European cannabis markets create problems and concerns about health and safety of intervention staff, dismantling companies, the direct environment of cannabis plantations and, eventually, of cannabis users. Main risks may come from pesticide residues on plants, cultivation infrastructure and materials; left-over plant growth-promoting substances; mycotoxins from fungal pathogens on harvested plants; and/or high levels of cannabinoids in cannabis plant parts for consumption. In the present research, we report on pesticides found in illicit indoor cannabis plantations in Belgium. EN15662 QuEChERS extraction method and LC-MS/MS analysis were used to identify pesticides in indoor cannabis plantations and thus to evaluate the hazards associated with the use, cultivation and removal of cannabis plants in plantations as well as with dismantling activities in the cultivation rooms. We found pesticides in 64.3% of 72 cannabis plant samples and in 65.2% of 46 carbon filter cloth samples. Overall, 19 pesticides belonging to different chemical classes were identified. We found o-phenylphenol, bifenazate, cypermethrin, imidacloprid, propamocarb, propiconazole and tebuconazole, which is consistent with the commonly reported pesticides from literature. In only a few cases, pesticides found in bottles with a commercial label, were also identified in plant or stagnant water samples collected from the growth rooms where the bottles had been collected. We further revealed that, even though most pesticides have a low volatility, they could be detected from the carbon filters hanging at the ceiling of cultivation rooms. As a result, it is likely that pesticides also prevail in the plantation atmosphere during and after cultivation. The risk of inhaling the latter pesticides increases when plants sprayed with pesticides are
Wu, Li-Tzy; Zhu, He; Swartz, Marvin S
Minority groups generally experience more disparities than whites in behavioral healthcare use. The population of racial/ethnic groups is growing faster than whites. Given increased concerns of cannabis use (CU) and its associations with health conditions, we examined national trends in cannabis use disorder (CUD) among adults aged ≥18 by race/ethnicity. Data were from the 2005-2013 National Surveys on Drug Use and Health (N=340,456). We compared CU patterns and the conditional prevalence of CUD among cannabis users by race/ethnicity to understand racial/ethnic variations in CUD. Approximately 1.5% of adults met criteria for a CUD in the past year. Regardless of survey year, cannabis dependence was more common than cannabis abuse, representing 66% of adults with a CUD. Across racial/ethnic groups, the prevalence of cannabis abuse and dependence remained stable during 2005-2013. In the total adult sample, the odds of weekly CU, monthly CU, and cannabis dependence were greater among blacks, native-Americans, and mixed-race adults than whites. Among cannabis users, the odds of cannabis abuse and dependence were greater among blacks, native-Americans, and Hispanics than whites. Logistic regression controlling for age, sex, education, and survey year indicated an increased trend in monthly CU and weekly CU in the total sample and among past-year cannabis users. Younger age, male sex, and low education were associated with increased odds of cannabis dependence. The large sample provides robust information that indicates a need for research to monitor CUD and identify culturally appropriate interventions especially for targeting minority populations. Copyright © 2016 The Author(s). Published by Elsevier Ireland Ltd.. All rights reserved.
February 2010. The terms searched were: "cannabi*" or "marijuana", and "cogniti*" or "memory" or "attention" or "executive function", and human studies were reviewed preferentially over the animal literature. DISCUSSION: Cannabis use impairs memory, attention, inhibitory control, executive functions and decision making, both during the period of acute intoxication and beyond, persisting for hours, days, weeks or more after the last use of cannabis. Pharmacological challenge studies in humans are elucidating the nature and neural substrates of cognitive changes associated with various cannabinoids. Long-term or heavy cannabis use appears to result in longer-lasting cognitive abnormalities and possibly structural brain alterations. Greater adverse cognitive effects are associated with cannabis use commencing in early adolescence. CONCLUSION: The endogenous cannabinoid system is involved in regulatory neural mechanisms that modulate processes underlying a range of cognitive functions that are impaired by cannabis. Deficits in human users most likely therefore reflect neuroadaptations and altered functioning of the endogenous cannabinoid system.
Corroon Jr JM
Full Text Available James M Corroon Jr,1 Laurie K Mischley,2 Michelle Sexton3 1Center for Medical Cannabis Education, Del Mar, CA, 2Bastyr University Research Institute, Kenmore, WA, 3Department of Medical Research, Center for the Study of Cannabis and Social Policy, Seattle, WA, USA Background: The use of medical cannabis is increasing, most commonly for pain, anxiety and depression. Emerging data suggest that use and abuse of prescription drugs may be decreasing in states where medical cannabis is legal. The aim of this study was to survey cannabis users to determine whether they had intentionally substituted cannabis for prescription drugs.Methods: A total of 2,774 individuals were a self-selected convenience sample who reported having used cannabis at least once in the previous 90 days. Subjects were surveyed via an online anonymous questionnaire on cannabis substitution effects. Participants were recruited through social media and cannabis dispensaries in Washington State.Results: A total of 1,248 (46% respondents reported using cannabis as a substitute for prescription drugs. The most common classes of drugs substituted were narcotics/opioids (35.8%, anxiolytics/benzodiazepines (13.6% and antidepressants (12.7%. A total of 2,473 substitutions were reported or approximately two drug substitutions per affirmative respondent. The odds of reporting substituting were 4.59 (95% confidence interval [CI], 3.87–5.43 greater among medical cannabis users compared with non-medical users and 1.66 (95% CI, 1.27–2.16 greater among those reporting use for managing the comorbidities of pain, anxiety and depression. A slightly higher percentage of those who reported substituting resided in states where medical cannabis was legal at the time of the survey (47% vs. 45%, p=0.58, but this difference was not statistically significant.Discussion: These patient-reported outcomes support prior research that individuals are using cannabis as a substitute for prescription drugs
Kreuter, M; Nowak, D; Rüther, T; Hoch, E; Thomasius, R; Vogelberg, C; Brockstedt, M; Hellmann, A; Gohlke, H; Jany, B; Loddenkemper, R
In this position paper, the adverse health effects of cannabis are reviewed based on the existing scientific literature; in addition possible symptom-relieving effects on some diseases are depicted. In Germany, cannabis is the most widely used illicit drug. Approximately 600,000 adult persons show abusive or addictive cannabis consumption. In 12 to 17 year old adolescents, cannabis use increased from 2011 to 2014 from 2.8 to 6.4%, and the frequency of regular use from 0.2 to 1.5%. Currently, handling of cannabinoids is much debated in politics as well as in general public. Health aspects have to be incorporated into this debate. Besides analysing mental and neurological side effects, this position paper will mainly focus on the influences on the bronchopulmonary and cardiovascular system. There is strong evidence for the induction of chronic bronchitis. Allergic reactions including asthma are known, too. Associations with other diseases like pulmonary emphysema, lung cancer and pneumonia are not sufficiently proven, however cannot be excluded either. In connection with the use of cannabis cardiovascular events such as coronary syndromes, peripheral vascular diseases and cerebral complications have been noted. Often, the evidence is insufficient due to various reasons; most notably, the overlapping effects of tobacco and cannabis use can frequently not be separated adequately. Empirically, early beginning, high-dosed, long-lasting and regular cannabis consumption increase the risk of various psychological and physical impairments and negatively affect age-based development. Concerns therefore relate especially to children and adolescents. There is only little scientific evidence for medical benefits through cannabis as a remedy; systematic research of good quality, in particular prospective, randomised, placebo-controlled double-blinded studies are rare. The medical societies signing this position paper conclude that cannabis consumption is linked to adverse health
Khiabani, Hassan Z; Mørland, Jørg; Bramness, Jørgen G
Delta 9-tetrahydrocannabinol (THC) is the major active component of cannabis. Cardiovascular effects of THC have previously been reported: tachycardia after intake, but also bradycardia at higher doses. The purpose of this study was, firstly, to investigate the frequency and irregularity of heart rate in a group of cannabis users in their natural surroundings. We also compared THC-positive drivers with a regular pulse with THC-positive drivers with an irregular pulse. The division of Forensic Toxicology and Drug Abuse (DFTDA) at the Norwegian Institute of Public Heath analyzes blood samples from all drivers suspected of driving under the influence of drugs. We studied pulse rate and regularity in 502 THC-positive drivers who tested negative for other substances. As a control group, we randomly selected 125 drug-negative cases from the database of the DFTDA; no alcohol, narcotics, or medicinal drugs of abuse were detected. The Delta9-THC-positive drivers had a higher mean pulse rate than the control group [82.8 beats/min (SD 16.3) versus 75.6 beats/min (SD 9.2)] and more cases with tachycardia were detected in the Delta9-THC-positive group (19.4% versus 1.6%). There was only one driver with an irregular heart beat in the control group, while there were nine among the Delta9-THC-positive drivers. The drivers with an irregular pulse were over-represented amongst those with the lowest blood Delta9-THC concentrations. This report represents a large study of subjects in a real-life situation and includes observations on pulse frequency, regularity, and blood Delta9-THC concentration. A substantial fraction of Delta9-THC-positive drivers had tachycardia, but there was no correlation between blood Delta9-THC concentration and pulse rate in the present study. We had no further diagnostic information on the cause of the pulse irregularities, but our results indicate that occasional users of cannabis tend to have irregular heart rates at low THC concentrations and at low
Boydell, J; Dean, K; Dutta, R; Giouroukou, E; Fearon, P; Murray, R
There is considerable interest in cannabis use in psychosis. It has been suggested that the chronic psychosis associated with cannabis use, is symptomatically distinct from idiopathic schizophrenia. Several studies have reported differences in psychopathology and family history in people with schizophrenia according to whether or not they were cannabis users. We set out to test the hypotheses arising from these studies that cannabis use is associated with more bizarre behaviour, more thought disorder, fewer negative symptoms including blunted affect, more delusions of reference, more paranoid delusions and a stronger family history of schizophrenia. We used a case register that contained 757 cases of first onset schizophrenia, 182 (24%) of whom had used cannabis in the year prior to first presentation, 552 (73%) had not and 3% had missing data. We completed the OPCRIT checklist on all patients and investigated differences in the proportion of people with distractibility, bizarre behaviour, positive formal thought disorder, delusions of reference, well organised delusions, any first rank symptom, persecutory delusions, abusive/accusatory hallucinations, blunted affect, negative thought disorder, any negative symptoms (catatonia, blunted affect, negative thought disorder, or deterioration), lack of insight, suicidal ideation and a positive family history of schizophrenia, using chi square tests. Logistic regression modelling was then used to determine whether prior cannabis use affected the presence of the characteristics after controlling for age, sex and ethnicity. There was no statistically significant effect of cannabis use on the presence of any of the above. There remained however a non-significant trend towards more insight (OR 0.65 p=0.055 for "loss of insight") and a finding of fewer abusive or accusatory hallucinations (OR 0.65 p=0.049) of borderline significance amongst the cannabis users. These were in the hypothesised direction. There was no evidence of
Engels, Frederike K; de Jong, Floris A; Mathijssen, Ron H J; Erkens, Joëlle A; Herings, Ron M; Verweij, Jaap
In The Netherlands, since September 2003, a legal medicinal cannabis product, constituting the whole range of cannabinoids, is available for clinical research, drug development strategies, and on prescription for patients. To date, this policy, initiated by the Dutch Government, has not yet led to the desired outcome; the amount of initiated clinical research is less than expected and only a minority of patients resorts to the legal product. This review aims to discuss the background for the introduction of legal medicinal cannabis in The Netherlands, the past years of Dutch clinical experience in oncology practice, possible reasons underlying the current outcome, and future perspectives.
Cousijn, Janna; Wiers, Reinout W; Ridderinkhof, K Richard; van den Brink, Wim; Veltman, Dick J; Porrino, Linda J; Goudriaan, Anna E
Decision-making deficits are thought to play an important role in the development and persistence of substance use disorders. Individual differences in decision-making abilities and their underlying neurocircuitry may, therefore, constitute an important predictor for the course of substance use and the development of substance use disorders. Here, we investigate the predictive value of decision making and neural mechanisms underlying decision making for future cannabis use and problem severity in a sample of heavy cannabis users. Brain activity during a monetary decision-making task (Iowa gambling task) was compared between 32 heavy cannabis users and 41 matched non-using controls using functional magnetic resonance imaging. In addition, within the group of heavy cannabis users, associations were examined between task-related brain activations, cannabis use and cannabis use-related problems at baseline, and change in cannabis use and problem severity after a 6-month follow-up. Despite normal task performance, heavy cannabis users compared with controls showed higher activation during wins in core areas associated with decision making. Moreover, within the group of heavy cannabis users, win-related activity and activity anticipating loss outcomes in areas generally involved in executive functions predicted change in cannabis use after 6 months. These findings are consistent with previous studies and point to abnormal processing of motivational information in heavy cannabis users. A new finding is that individuals who are biased toward immediate rewards have a higher probability of increasing drug use, highlighting the importance of the relative balance between motivational processes and regulatory executive processes in the development of substance use disorders. © 2012 The Authors, Addiction Biology © 2012 Society for the Study of Addiction.
Jacobson, Mireille; Maksabedian, Ervant J
Aims To describe patterns of cannabis use, the degree of overlap between medicinal and recreational users, and their differential use patterns, modes of consumption and sources of cannabis. Design An ongoing probability-based internet panel maintained by the market research firm GfK Group. Setting Households in Colorado, Washington, Oregon and New Mexico, USA. Participants 2009 individuals from Washington (n=787), Oregon (n=506), Colorado (n=503), and New Mexico (N=213). Post stratification sampling weights were provided so that estimates could be made representative of the household population in each of these states. Respondents were between 18 and 91 years old with a mean age of 53. Methods We compare patterns of cannabis consumption for medicinal and recreational users as well as simultaneous use of alcohol and cannabis. We also examine the extent to which patterns of use differ across states that chose to legalize (Washington and Colorado) and those that did not (New Mexico and Oregon). Findings Rates of lifetime medical cannabis use are similar in Colorado and Washington (8·8% and 8·2%) but lower in Oregon and New Mexico (6.5% and 1%). Recreational use is considerably higher than medical use across all states (41%) but highest in Oregon and Washington. About 86% of people who report ever using cannabis for medicinal purposes also use it recreationally. Medical users are more likely to vaporize and consume edibles, and report a higher amount (in grams) consumed, and spend more money per month than recreational users. Individuals who use cannabis do not commonly use it with alcohol, irrespective of whether they are consuming cannabis recreationally or medically. Fewer than 1 in 5 recreational users report simultaneous use of alcohol and cannabis most or all of the time and less than 3% of medicinal users report frequent simultaneous use of alcohol and cannabis. Conclusions In the USA, the degree of overlap between medicinal and recreational cannabis users is
Hansen, Lars Kai; Rasmussen, Carl Edward; Svarer, C.
Regularization, e.g., in the form of weight decay, is important for training and optimization of neural network architectures. In this work the authors provide a tool based on asymptotic sampling theory, for iterative estimation of weight decay parameters. The basic idea is to do a gradient desce...
Minor, Kyle S; Firmin, Ruth L; Bonfils, Kelsey A; Chun, Charlotte A; Buckner, Julia D; Cohen, Alex S
Evidence suggests that divergent thinking (DT), a measure of creativity, is associated with positive schizotypy and cannabis use. Given the high rates of cannabis use among those with schizotypy, it is unclear if the relation of DT to schizotypy is due to co-occurring cannabis use. In this study, we examined the relations between DT, schizotypy, and cannabis use among positive schizotypy (n=66), negative schizotypy (n=22), and non-schizotypy (n=60) groups. Results revealed that DT was greater in the positive schizotypy group, on the order of small to medium effects, compared to negative and non-schizotypy groups. Cannabis use and DT were associated in the non-schizotypy group, but not in the positive or negative schizotypy groups. Across all groups, positive schizotypy significantly predicted DT; however, cannabis use was not a significant predictor of DT. In line with previous findings, cannabis use and DT were only related in individuals low in creativity. This suggests that a ceiling effect may be present, with only cannabis users who are low in creativity receiving any increase in DT. Future research should aim to clarify the DT-cannabis relationship. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.
Cousijn, Janna; Vingerhoets, Wilhelmina A. M.; van den Brink, Wim; Wiers, Reinout W.; Meijer, Carin J.; Machielsen, Marise W. J.; Veltman, Dick J.; Goudriaan, Anneke E.; de Haan, Lieuwe
Cannabis is the most frequently used illicit drug worldwide. Cross-sectional neuroimaging studies suggest that chronic cannabis exposure and the development of cannabis use disorders may affect brain morphology. However, cross-sectional studies cannot make a conclusive distinction between cause and consequence and longitudinal neuroimaging studies are lacking. In this prospective study we investigate whether continued cannabis use and higher levels of cannabis exposure in young adults are associated with grey matter reductions. Heavy cannabis users (N = 20, age baseline M = 20.5, SD = 2.1) and non-cannabis using healthy controls (N = 22, age baseline M = 21.6, SD = 2.45) underwent a comprehensive psychological assessment and a T1- structural MRI scan at baseline and 3 years follow-up. Grey matter volumes (orbitofrontal cortex, anterior cingulate cortex, insula, striatum, thalamus, amygdala, hippocampus and cerebellum) were estimated using the software package SPM (VBM-8 module). Continued cannabis use did not have an effect on GM volume change at follow-up. Cross-sectional analyses at baseline and follow-up revealed consistent negative correlations between cannabis related problems and cannabis use (in grams) and regional GM volume of the left hippocampus, amygdala and superior temporal gyrus. These results suggests that small GM volumes in the medial temporal lobe are a risk factor for heavy cannabis use or that the effect of cannabis on GM reductions is limited to adolescence with no further damage of continued use after early adulthood. Long-term prospective studies starting in early adolescence are needed to reach final conclusions. PMID:27224247
Full Text Available Cannabis is the most frequently used illicit drug worldwide. Cross-sectional neuroimaging studies suggest that chronic cannabis exposure and the development of cannabis use disorders may affect brain morphology. However, cross-sectional studies cannot make a conclusive distinction between cause and consequence and longitudinal neuroimaging studies are lacking. In this prospective study we investigate whether continued cannabis use and higher levels of cannabis exposure in young adults are associated with grey matter reductions. Heavy cannabis users (N = 20, age baseline M = 20.5, SD = 2.1 and non-cannabis using healthy controls (N = 22, age baseline M = 21.6, SD = 2.45 underwent a comprehensive psychological assessment and a T1- structural MRI scan at baseline and 3 years follow-up. Grey matter volumes (orbitofrontal cortex, anterior cingulate cortex, insula, striatum, thalamus, amygdala, hippocampus and cerebellum were estimated using the software package SPM (VBM-8 module. Continued cannabis use did not have an effect on GM volume change at follow-up. Cross-sectional analyses at baseline and follow-up revealed consistent negative correlations between cannabis related problems and cannabis use (in grams and regional GM volume of the left hippocampus, amygdala and superior temporal gyrus. These results suggests that small GM volumes in the medial temporal lobe are a risk factor for heavy cannabis use or that the effect of cannabis on GM reductions is limited to adolescence with no further damage of continued use after early adulthood. Long-term prospective studies starting in early adolescence are needed to reach final conclusions.
Full Text Available Although depressive symptoms in first episode psychosis have been associated with cannabis abuse, their influence on the long-term functional course of FEP patients who abuse cannabis is unknown. The aims of the study were to examine the influence of subclinical depressive symptoms on the long-term outcome in first episode-psychosis patients who were cannabis users and to assess the influence of these subclinical depressive symptoms on the ability to quit cannabis use.64 FEP patients who were cannabis users at baseline were followed-up for 5 years. Two groups were defined: (a patients with subclinical depressive symptoms at least once during follow-up (DPG, and (b patients without subclinical depressive symptoms during follow-up (NDPG. Psychotic symptoms were measured using the Positive and Negative Syndrome Scale (PANSS, depressive symptoms using the Hamilton Depression Rating Scale (HDRS-17, and psychosocial functioning was assessed using the Global Assessment of Functioning (GAF. A linear mixed-effects model was used to analyze the combined influence of cannabis use and subclinical depressive symptomatology on the clinical outcome.Subclinical depressive symptoms were associated with continued abuse of cannabis during follow-up (β= 4.45; 95% confidence interval [CI]: 1.78 to 11.17; P = .001 and with worse functioning (β = -5.50; 95% CI: -9.02 to -0.33; P = .009.Subclinical depressive symptoms and continued cannabis abuse during follow-up could be predictors of negative outcomes in FEP patients.
Full Text Available Jan Copeland, Izabella Pokorski UNSW Medicine, University of New South Wales, Sydney, NSW, Australia Abstract: Cannabis is the most widely used and variably regulated drug in the world, with increasing trends of use being reported in the US, Australia, Asia, and Africa. Evidence has shown a decrease in the age of commencement of cannabis use in some developed countries and a prolongation of risk of initiation to cannabis use beyond adolescence among more recent users. Cannabis use is associated with numerous health risks and long-term morbidity, as well as risk of developing cannabis-use disorders. Cannabis users infrequently seek professional treatment, and normally do so after a decade of use. Cannabis-use disorders are currently treated using a selection of psychosocial interventions. Severity of withdrawal is a factor that increases the risk of relapse, and is the target of pharmacotherapy studies. Currently, there is no approved pharmacotherapy for cannabis-use disorders. A number of approaches have been examined, and trials are continuing to find a safe and effective medication with little abuse liability. Keywords: marijuana, treatment, intervention, withdrawal, cannabinoid
Copeland, Jan; Pokorski, Izabella
Cannabis is the most widely used and variably regulated drug in the world, with increasing trends of use being reported in the US, Australia, Asia, and Africa. Evidence has shown a decrease in the age of commencement of cannabis use in some developed countries and a prolongation of risk of initiation to cannabis use beyond adolescence among more recent users. Cannabis use is associated with numerous health risks and long-term morbidity, as well as risk of developing cannabis-use disorders. Cannabis users infrequently seek professional treatment, and normally do so after a decade of use. Cannabis-use disorders are currently treated using a selection of psychosocial interventions. Severity of withdrawal is a factor that increases the risk of relapse, and is the target of pharmacotherapy studies. Currently, there is no approved pharmacotherapy for cannabis-use disorders. A number of approaches have been examined, and trials are continuing to find a safe and effective medication with little abuse liability. PMID:27217809
Nestoros, Joannis N; Vakonaki, Elena; Tzatzarakis, Manolis N; Alegakis, Athanasios; Skondras, Markos D; Tsatsakis, Aristidis M
The purpose of this study was to evaluate the extent of short-term memory impairment and schizophrenia-like symptoms in heavy and systematic cannabis users and the association between the severity of abuse and the longevity of its persistent symptoms after refraining from such use. A complete psychiatric examination and a psychometric evaluation were performed in 48 solely cannabis users. Additionally, head hair samples were analyzed and the detected cannabinoids levels were correlated with the psychometric findings. A total of 33.3% (n = 16) of the total examined cannabis users were currently imprisoned. The years of abuse ranged from 1 to 35 years and the median daily dose was 5.84.4 gr and 4.84.0 gr for prisoners (n = 16) and non prisoners (n = 32), respectively. A total of 39.6% of the users experienced hallucinations (mostly auditory), 54.2% experienced delusions (mostly ideas of reference and persecution), 85.4% had organic brain dysfunction in a test addressing visual-motor functioning and visual perception skills, and all users (100%) were found to have organic brain dysfunction in a test of visual memory immediate recall. The cannabinoid metabolite levels in the hair samples were consistent with the reported history of substance abuse and total grams of consumption for the participants below 35 years old (p cannabis users seems to be associated with cannabinoid levels in hair. The continuation of persistent symptoms 3 months after the discontinuation of cannabis abuse, was a remarkable finding. We provide evidence that chronic and heavy cannabis abuse results in long-lasting brain dysfunction in all users and in long-lasting schizophrenia-like psychotic symptoms in more than half of all users. These findings suggest a reevaluation of the current classification of cannabis as a "soft narcotic" which erroneously, therefore, is typically considered harmless. (Am J Addict 2017;26:335-342). © 2017 American Academy of Addiction Psychiatry.
Desbois, Anne Claire; Cacoub, Patrice
The aim of this study was to describe the different arterial complications reported in cannabis smokers. This study was a literature review. Cannabis use was found to be associated with stroke, myocardial infarction, and lower limb arteritis. Arterial disease involved especially young men. There was a very strong temporal link between arterial complications and cannabis use for stroke and myocardial infarction episodes. Patient outcome was closely correlated with cannabis withdrawal and relapses associated with cannabis rechallenge. Cannabis use was associated with particular characteristics of arterial disease. The increased risk of myocardial infarction onset occurred within 1 hour of smoking marijuana compared with periods of non-use. Strokes occurred mainly in the posterior cerebral circulation. Compared with cohorts of thromboangiitis obliterans patients, those with cannabis-associated limb arteritis were younger, more often male, and had more frequent unilateral involvement of the lower limbs at clinical presentation. Cannabis use is associated with arterial disease such as stroke, myocardial infarction, and limbs arteritis. It appears essential to investigate cannabis use in young patients presenting with such arterial manifestations, as outcome is closely correlated with cannabis withdrawal. Copyright © 2013 Elsevier Inc. All rights reserved.
Griffith-Lendering, Merel Frederique Heleen
During early adolescence, there is no association between internalizing behaviour and cannabis use. There is an association between externalizing behaviour and cannabis use, where externalizing behaviour precedes cannabis use rather than the other way around. Secondly, during adolescence, there is
Hartman, Rebecca L; Huestis, Marilyn A
Cannabis is the most prevalent illicit drug identified in impaired drivers. The effects of cannabis on driving continue to be debated, making prosecution and legislation difficult. Historically, delays in sample collection, evaluating the inactive Δ(9)-tetrahydrocannabinol (THC) metabolite 11-nor-9-carboxy-THC, and polydrug use have complicated epidemiologic evaluations of driver impairment after cannabis use. We review and evaluate the current literature on cannabis' effects on driving, highlighting the epidemiologic and experimental data. Epidemiologic data show that the risk of involvement in a motor vehicle accident (MVA) increases approximately 2-fold after cannabis smoking. The adjusted risk of driver culpability also increases substantially, particularly with increased blood THC concentrations. Studies that have used urine as the biological matrix have not shown an association between cannabis and crash risk. Experimental data show that drivers attempt to compensate by driving more slowly after smoking cannabis, but control deteriorates with increasing task complexity. Cannabis smoking increases lane weaving and impaired cognitive function. Critical-tracking tests, reaction times, divided-attention tasks, and lane-position variability all show cannabis-induced impairment. Despite purported tolerance in frequent smokers, complex tasks still show impairment. Combining cannabis with alcohol enhances impairment, especially lane weaving. Differences in study designs frequently account for inconsistencies in results between studies. Participant-selection bias and confounding factors attenuate ostensible cannabis effects, but the association with MVA often retains significance. Evidence suggests recent smoking and/or blood THC concentrations 2-5 ng/mL are associated with substantial driving impairment, particularly in occasional smokers. Future cannabis-and-driving research should emphasize challenging tasks, such as divided attention, and include occasional and
Flávia Serebrenic Jungerman
Full Text Available OBJECTIVES: This article describes a sample of 160 adults selected to participate in a randomized controlled trial conducted at a specialized outpatient clinic for cannabis users in Brazil. It correlates consumption with several measures of marijuana use, comparing it with other samples. METHODS: Instruments used were the Composite International Diagnostic Interview (CIDI and Wender Utah Rating Scale for screening and demographic data interviews, and the ASI, time-line follow back (TLFB, Marijuana Withdrawal and Marijuana Problem Scales, and Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R Checklist for cannabis dependence. RESULTS: Participants in the study were mostly single, white men; their mean age was 32.3 years. They had a mean of 15.6 years of formal education and 61.6% worked. The cohort started using marijuana at a mean age of 16.5 years and developed daily use by a mean age of 21 years. Subjects in the sample had used marijuana for a mean of 15 years. They used it for 92.2% of the 90 days prior to the interview and smoked a mean of 1.99 marijuana cigarettes per day during this period. Individuals in the group had experimented with other drugs, especially cocaine. CONCLUSIONS: Marijuana users in this sample matched the profiles of those investigated elsewhere, although they reported fewer symptoms of dependence. Marijuana users should be considered independently in substance abuse programs, because they require specific attention and treatment. Broader epidemiological studies should be conducted to determine the extent of marijuana use within the Brazilian population.OBJETIVOS: Describir una muestra de 160 adultos seleccionados para participar en un ensayo aleatorizado controlado, realizado en una clínica ambulatoria especializada para consumidores de marihuana en Brasil. Se asoció el consumo de marihuana con varias medidas relacionadas con este hábito y se comparó con otras muestras. MÉTODOS: Se empleó la
Hill, Kevin P.; Palastro, Matthew D.; Johnson, Brian; Ditre, Joseph W.
Abstract Introduction: Cannabis has been used for medical purposes across the world for centuries. As states and countries implement medical and recreational cannabis policies, increasing numbers of people are using cannabis pharmacotherapy for pain. There is a theoretical rationale for cannabis' efficacy for pain management, although the subjective pain relief from cannabis may not match objective measurements of analgesia. As more patients turn to cannabis for pain relief, there is a need f...
Ware, Mark A; Wang, Tongtong; Shapiro, Stan; Collet, Jean-Paul
Cannabis is widely used as a self-management strategy by patients with a wide range of symptoms and diseases including chronic non-cancer pain. The safety of cannabis use for medical purposes has not been systematically evaluated. We conducted a prospective cohort study to describe safety issues among individuals with chronic non-cancer pain. A standardized herbal cannabis product (12.5% tetrahydrocannabinol) was dispensed to eligible individuals for a 1-year period; controls were individuals with chronic pain from the same clinics who were not cannabis users. The primary outcome consisted of serious adverse events and non-serious adverse events. Secondary safety outcomes included pulmonary and neurocognitive function and standard hematology, biochemistry, renal, liver, and endocrine function. Secondary efficacy parameters included pain and other symptoms, mood, and quality of life. Two hundred and fifteen individuals with chronic pain were recruited to the cannabis group (141 current users and 58 ex-users) and 216 controls (chronic pain but no current cannabis use) from 7 clinics across Canada. The median daily cannabis dose was 2.5 g/d. There was no difference in risk of serious adverse events (adjusted incidence rate ratio = 1.08, 95% confidence interval = .57-2.04) between groups. Medical cannabis users were at increased risk of non-serious adverse events (adjusted incidence rate ratio = 1.73, 95% confidence interval = 1.41-2.13); most were mild to moderate. There were no differences in secondary safety assessments. Quality-controlled herbal cannabis, when used by patients with experience of cannabis use as part of a monitored treatment program over 1 year, appears to have a reasonable safety profile. Longer-term monitoring for functional outcomes is needed. The study was registered with www.controlled-trials.com (ISRCTN19449752). This study evaluated the safety of cannabis use by patients with chronic pain over 1 year. The study found that there was a higher
Roulette, Casey J; Kazanji, Mirdad; Breurec, Sébastien; Hagen, Edward H
Little is known about cannabis use in hunter-gatherers. Therefore, we investigated cannabis use in the Aka, a population of foragers of the Congo Basin. Because cannabis contains anthelminthic compounds, and the Aka have a high prevalence of helminthiasis, we also tested the hypothesis that cannabis use might be an unconscious form of self-medication against helminths. We collected self- and peer-reports of cannabis use from all adult Aka in the Lobaye district of the Central African Republic (n = 379). Because female cannabis use was low, we restricted sample collection to men. Using an immunoassay for Δ9-tetrahydrocannabinol-11-oic acid (THCA), a urinary biomarker of recent cannabis consumption, we validated cannabis use in men currently residing in camps near a logging road (n = 62). We also collected stool samples to assay worm burden. A longitudinal reinfection study was conducted among a subsample of the male participants (n = 23) who had been treated with a commercial anthelmintic 1 year ago. The prevalence of self- and peer-reported cannabis use was 70.9% among men and 6.1% among women, for a total prevalence of 38.6%. Using a 50 ng/ml threshold for THCA, 67.7% of men used cannabis. Cannabis users were significantly younger and had less material wealth than the non-cannabis users. There were significant negative associations between THCA levels and worm burden, and reinfection with helminths 1 year after treatment with a commercial anthelmintic. The prevalence of cannabis use among adult Aka men was high when compared to most global populations. THCA levels were negatively correlated with parasite infection and reinfection, supporting the self-medication hypothesis. © 2015 Wiley Periodicals, Inc.
Cervený, J.; van Ours, J.C.; Chomynova, Pavla; Mravcik, Viktor
This paper examines the effect of a change in drugs policy on the age of onset of cannabis use. We use 2012 survey data from the Czech Republic where in 2010 a law was introduced decriminalizing personal possession of small quantities of several illicit drugs, including cannabis. We estimate the effect of the policy change using a mixed proportional hazards framework that models the starting rate of cannabis use, i.e. the transition to first cannabis use. We find that the decriminalization of...
Polosa, Riccardo; Cibella, Fabio; Caponnetto, Pasquale; Maglia, Marilena; Prosperini, Umberto; Russo, Cristina; Tashkin, Donald
Although electronic cigarettes (ECs) are a much less harmful alternative to tobacco cigarettes, there is concern as to whether long-term ECs use may cause risks to human health. We report health outcomes (blood pressure, heart rate, body weight, lung function, respiratory symptoms, exhaled breath nitric oxide [eNO], exhaled carbon monoxide [eCO], and high-resolution computed tomography [HRCT] of the lungs) from a prospective 3.5-year observational study of a cohort of nine daily EC users (mean age 29.7 (±6.1) years) who have never smoked and a reference group of twelve never smokers. No significant changes could be detected over the observation period from baseline in the EC users or between EC users and control subjects in any of the health outcomes investigated. Moreover, no pathological findings could be identified on HRCT of the lungs and no respiratory symptoms were consistently reported in the EC user group. Although it cannot be excluded that some harm may occur at later stages, this study did not demonstrate any health concerns associated with long-term use of EC in relatively young users who did not also smoke tobacco.
Murray, Robin M; Quigley, Harriet; Quattrone, Diego; Englund, Amir; Di Forti, Marta
Epidemiological evidence demonstrates that cannabis use is associated with an increased risk of psychotic outcomes, and confirms a dose-response relationship between the level of use and the risk of later psychosis. High-potency cannabis and synthetic cannabinoids carry the greatest risk. Experimental administration of tetrahydrocannabinol, the active ingredient of cannabis, induces transient psychosis in normal subjects, but this effect can be ameliorated by co-administration of cannabidiol. This latter is a constituent of traditional hashish, but is largely absent from modern high-potency forms of cannabis. Argument continues over the extent to which genetic predisposition is correlated to, or interacts with, cannabis use, and what proportion of psychosis could be prevented by minimizing heavy use. As yet, there is not convincing evidence that cannabis use increases risk of other psychiatric disorders, but there are no such doubts concerning its detrimental effect on cognitive function. All of the negative aspects are magnified if use starts in early adolescence. Irrespective of whether use of cannabis is decriminalized or legalized, the evidence that it is a component cause of psychosis is now sufficient for public health messages outlining the risk, especially of regular use of high-potency cannabis and synthetic cannabinoids. © 2016 World Psychiatric Association.
Murray, Robin M.; Quigley, Harriet; Quattrone, Diego; Englund, Amir; Di Forti, Marta
Epidemiological evidence demonstrates that cannabis use is associated with an increased risk of psychotic outcomes, and confirms a dose‐response relationship between the level of use and the risk of later psychosis. High‐potency cannabis and synthetic cannabinoids carry the greatest risk. Experimental administration of tetrahydrocannabinol, the active ingredient of cannabis, induces transient psychosis in normal subjects, but this effect can be ameliorated by co‐administration of cannabidiol. This latter is a constituent of traditional hashish, but is largely absent from modern high‐potency forms of cannabis. Argument continues over the extent to which genetic predisposition is correlated to, or interacts with, cannabis use, and what proportion of psychosis could be prevented by minimizing heavy use. As yet, there is not convincing evidence that cannabis use increases risk of other psychiatric disorders, but there are no such doubts concerning its detrimental effect on cognitive function. All of the negative aspects are magnified if use starts in early adolescence. Irrespective of whether use of cannabis is decriminalized or legalized, the evidence that it is a component cause of psychosis is now sufficient for public health messages outlining the risk, especially of regular use of high‐potency cannabis and synthetic cannabinoids. PMID:27717258
Hartman, Rebecca L.; Huestis, Marilyn A.
BACKGROUND Cannabis is the most prevalent illicit drug identified in impaired drivers. The effects of cannabis on driving continue to be debated, making prosecution and legislation difficult. Historically, delays in sample collection, evaluating the inactive Δ9-tetrahydrocannabinol (THC) metabolite 11-nor-9-carboxy-THC, and polydrug use have complicated epidemiologic evaluations of driver impairment after cannabis use. CONTENT We review and evaluate the current literature on cannabis’ effects on driving, highlighting the epidemiologic and experimental data. Epidemiologic data show that the risk of involvement in a motor vehicle accident (MVA) increases approximately 2-fold after cannabis smoking. The adjusted risk of driver culpability also increases substantially, particularly with increased blood THC concentrations. Studies that have used urine as the biological matrix have not shown an association between cannabis and crash risk. Experimental data show that drivers attempt to compensate by driving more slowly after smoking cannabis, but control deteriorates with increasing task complexity. Cannabis smoking increases lane weaving and impaired cognitive function. Critical-tracking tests, reaction times, divided-attention tasks, and lane-position variability all show cannabis-induced impairment. Despite purported tolerance in frequent smokers, complex tasks still show impairment. Combining cannabis with alcohol enhances impairment, especially lane weaving. SUMMARY Differences in study designs frequently account for inconsistencies in results between studies. Participant-selection bias and confounding factors attenuate ostensible cannabis effects, but the association with MVA often retains significance. Evidence suggests recent smoking and/or blood THC concentrations 2–5 ng/mL are associated with substantial driving impairment, particularly in occasional smokers. Future cannabis-and-driving research should emphasize challenging tasks, such as divided attention
Abuso e dependência de maconha: comparação entre sexos e preparação para mudanças comportamentais entre usuários que iniciam a busca por tratamento Cannabis abuse and dependency: differences between men and women and readiness to behavior change among users seeking treatment
Full Text Available OBJETIVOS: Descrever o perfil sociodemográfico de usuários de maconha que iniciam tratamento e comparar os sexos dos indivíduos em relação aos estágios de prontidão para mudança e uso associado de outras drogas. MÉTODO: Estudo transversal descritivo, com amostra não probabilística de indivíduos que ligaram para um teleatendimento especializado em dependência química. RESULTADOS: A amostra se constituiu de 72% de indivíduos do sexo masculino na faixa etária de 12 a 25 anos. Um percentual de 85,5% fazia uso associado de outras drogas. O estágio motivacional predominante foi de ação (56%, sem diferenças entre sexos (p = 0,4. Os homens mais frequentemente procuraram auxílio para o tratamento do uso de maconha. CONCLUSÕES: Com base nesses dados, foi possível delinear o perfil dos usuários de maconha para auxiliar no direcionamento de informações e atendimento adequado.OBJECTIVES: To describe the social and demographic profile of cannabis users seeking treatment and to compare differences between sex in relation to readiness to behavior change and in relation to associated use of marijuana and other drugs. METHOD: A cross-sectional, descriptive study including a nonprobability sample of individuals who called a chemical dependency hotline. RESULTS: The sample comprised 72% male individuals aged between 12 and 25 years. The sample was composed by 85.5% used other drugs in association with cannabis. The action stage was the most frequent stage of readiness to behavior change observed, in 56% of the callers, with no differences between sex (p = 0.4. Men more frequently sought treatment for the use of cannabis. CONCLUSIONS: Our findings allowed delineating a profile of cannabis users, so as to better guide the provision of adequate information and treatment services.
van Leeuwen, Andrea Prince; Creemers, Hanneke E.; Verhulst, Frank C.; Ormel, Johan; Huizink, Anja C.
Objective: This study examined (a) the predictive value of observed versus reported measures of impulsivity on the onset of cannabis use and determined if lifetime tobacco and cannabis users can be differentiated by their level of impulsivity and (b) the predictive value of observed versus reported
Full Text Available Nicole P Bowles, Maya X Herzig, Steven A Shea Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, USAThe recent legalization of cannabis for medical and recreational use in many states in the United States and internationally4,5 has resulted in a decrease in stigma and of perceived risk of cannabis use, more frequent use of cannabis, use of higher potency cannabis products, and increased dependence on cannabis use.6–8 Cannabis sativa and its derivatives are often used for improved sleep and relaxation; characteristics originally attributed to Indian hemp in the nineteenth century.1–3 Cannabis alters the sleep–wake cycle, increases the production of melatonin, and can inhibit the arousal system by activating cannabinoid type 1 (CB1 receptors in the basal forebrain and other wakepromoting centers.9–12 Investigations have shown that the major psychoactive compound in cannabis, Δ9-tetrahydrocannabinol (THC, can decrease sleep onset latency in naïve users or at low doses in experienced users (eg, 70 mg/day; however, higher doses in experienced users increased sleep latency and wake after sleep onset.9,13,14 Indeed, frequent cannabis users (≥5 uses/week for 3 months and lifetime use ≥2 years are reported to have shorter total sleep duration, less slow wave sleep, worse sleep efficiency, and longer sleep onset compared to controls.15 The contrasting benefits of THC exposure may represent the biphasic influence of THC on CB1 receptors whereby acute use causes more activation of CB1 receptors and tendency toward sleep, but long-term use results in desensitization of the CB1 receptor and decreased downstream signaling.
Hazekamp, A; Fischedick, J T
The medicinal use of Cannabis is increasing as countries worldwide are setting up official programs to provide patients with access to safe sources of medicinal-grade Cannabis. An important question that remains to be answered is which of the many varieties of Cannabis should be made available for medicinal use. Drug varieties of Cannabis are commonly distinguished through the use of popular names, with a major distinction being made between Indica and Sativa types. Although more than 700 different cultivars have already been described, it is unclear whether such classification reflects any relevant differences in chemical composition. Some attempts have been made to classify Cannabis varieties based on chemical composition, but they have mainly been useful for forensic applications, distinguishing drug varieties, with high THC content, from the non-drug hemp varieties. The biologically active terpenoids have not been included in these approaches. For a clearer understanding of the medicinal properties of the Cannabis plant, a better classification system, based on a range of potentially active constituents, is needed. The cannabinoids and terpenoids, present in high concentrations in Cannabis flowers, are the main candidates. In this study, we compared cultivars obtained from multiple sources. Based on the analysis of 28 major compounds present in these samples, followed by principal component analysis (PCA) of the quantitative data, we were able to identify the Cannabis constituents that defined the samples into distinct chemovar groups. The study indicates the usefulness of a PCA approach for chemotaxonomic classification of Cannabis varieties. Copyright © 2012 John Wiley & Sons, Ltd.
Fábregas, Josep Maria; González, Débora; Fondevila, Sabela; Cutchet, Marta; Fernández, Xavier; Barbosa, Paulo César Ribeiro; Alcázar-Córcoles, Miguel Ángel; Barbanoj, Manel J; Riba, Jordi; Bouso, José Carlos
Ayahuasca is a psychoactive beverage used for magico-religious purposes in the Amazon. Recently, Brazilian syncretic churches have helped spread the ritual use of ayahuasca abroad. This trend has raised concerns that regular use of this N,N-dimethyltryptamine-containing tea may lead to the medical and psychosocial problems typically associated with drugs of abuse. Here we assess potential drug abuse-related problems in regular ayahuasca users. Addiction severity was assessed using the Addiction Severity Index (ASI), and history of alcohol and illicit drug use was recorded. In Study 1, jungle-based ayahuasca users (n=56) were compared vs. rural controls (n=56). In Study 2, urban-based ayahuasca users (n=71) were compared vs. urban controls (n=59). Follow-up studies were conducted 1 year later. In both studies, ayahuasca users showed significantly lower scores than controls on the ASI Alcohol Use, and Psychiatric Status subscales. The jungle-based ayahuasca users showed a significantly higher frequency of previous illicit drug use but this had ceased at the time of examination, except for cannabis. At follow-up, abstinence from illicit drug use was maintained in both groups except for cannabis in Study 1. However, differences on ASI scores were still significant in the jungle-based group but not in the urban group. Despite continuing ayahuasca use, a time-dependent worsening was only observed in one subscale (Family/Social relationships) in Study 2. Overall, the ritual use of ayahuasca, as assessed with the ASI in currently active users, does not appear to be associated with the deleterious psychosocial effects typically caused by other drugs of abuse. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
Hesse, Morten; Tutenges, Sébastien; Schliewe, Sanna
users who had not used a substance in the past 12 months. Results: New onset of tobacco use was reported by 9.2% of never-smokers, and new onset of cannabis use was reported by 9.3% of never-smokers of cannabis. Resumption of tobacco use was reported by 24% of past year abstainers, and resumption...... of cannabis use was reported by 30% of past year abstainers. New onset of other types of substances was reported by less than 0.5% of subjects, but among past year abstainers, 5–10% reported resumption of amphetamine, ketamine, MDMA and cocaine use. New onset smokers of cannabis were significantly younger...... than never-smokers. Conclusion: Music festivals such as the Roskilde Festival may be important arenas for the prevention of onset of tobacco and cannabis use and for a return to substance use....
Álvarez, Arturo; Gamella, Juan F; Parra, Iván
First, this paper estimates the dimensions of the market for cannabis in Spain using data on the extent of consumption and the main patterns of use of consumers. Then the paper reviews the hypothetical production and distribution costs of these drugs in different production regimes under different legal conditions. The review shows that current prices of cannabis in the illegal market could be notably reduced if production and distribution of cannabis were decriminalized and even more if they were performed by legal enterprises. Thirdly, we examine the relationship between prices and consumption levels by analysing the price elasticity of demand. A fall in the prices of cannabis products will likely result in an increase in the number of users and in the total amount consumed. Lastly we consider several alternatives for the taxation of cannabis derivatives to counteract the likely fall in prices, and their pros and cons.
Weinstein, A; Brickner, O; Lerman, H; Greemland, M; Bloch, M; Lester, H; Chisin, R; Sarne, Y; Mechoulam, R; Bar-Hamburger, R; Freedman, N; Even-Sapir, E
Heavy use of marijuana is claimed to damage critical skills related to short-term memory, visual scanning and attention. Motor skills and driving safety may be compromised by the acute effects of marijuana. The aim of this study was to investigate the acute effects of 13 mg and 17 mg Delta 9-tetrahydrocannabinol (THC) on skills important for coordinated movement and driving and on subjective and autonomic measures in regular users of marijuana. Fourteen regular users of marijuana were enrolled. Each subject was tested on two separate days. On each test day, subjects smoked two low-nicotine cigarettes, one with and the other without THC. Seventeen mg THC was included in the cigarette on one test day and 13 mg on the other day. The sequence of cigarette types was unknown to the subject. During smoking, heart rate and blood pressure were monitored, and the subjects performed a virtual reality maze task requiring attention and motor coordination, followed by 3 other cognitive tasks (Wisconsin Card Sorting Test (WCST), a "gambling" task and estimation of time and distance from an approaching car). After smoking a cigarette with 17 mg THC, regular marijuana users hit the walls more often on the virtual maze task than after smoking cigarettes without THC; this effect was not seen in patients after they smoked cigarettes with 13 mg THC. Performance in the WCST was affected with 17 mg THC and to a lesser extent with the use of 13 mg THC. Decision making in the gambling task was affected after smoking cigarettes with 17 mg THC, but not with 13 m THC. Smoking cigarettes with 13 and 17 mg THC increased subjective ratings of pleasure and satisfaction, drug "effect" and drug "high". These findings imply that smoking of 17 mg THC results in impairment of cognitive-motor skills that could be important for coordinated movement and driving, whereas the lower dose of 13 mg THC appears to cause less impairment of such skills in regular users of marijuana.
Shakoor, Sania; Zavos, Helena M.S.; McGuire, Philip; Cardno, Alastair G.; Freeman, Daniel; Ronald, Angelica
Cannabis users are more likely to have psychotic experiences (PEs). The degree to which these associations are driven by genetic or environmental influences in adolescence is unknown. This study estimated the genetic and environmental contributions to the relationship between cannabis use and PEs. Specific PEs were measured in a community-based twin sample (4830 16-year-old pairs) using self-reports and parent-reports. Adolescents reported on ever using cannabis. Multivariate liability threshold structural equation model-fitting was conducted. Cannabis use was significantly correlated with PEs. Modest heritability (37%), common environmental influences (55%) and unique environment (8%) were found for cannabis use. For PEs, modest heritability (27–54%), unique environmental influences (E=12–50%) and little common environmental influences (11–20%), with the exception of parent-rated Negative Symptoms (42%), were reported. Environmental influences explained all of the covariation between cannabis use and paranoia, cognitive disorganization and parent-rated negative symptoms (bivariate common environment=69–100%, bivariate unique environment=28–31%), whilst the relationship between cannabis use and hallucinations indicated familial influences. Cannabis use explains 2–5% of variance in positive, cognitive, and negative PEs. Cannabis use and psychotic experience co-occur due to environmental factors. Focus on specific environments may reveal why adolescent cannabis use and psychotic experiences tend to ‘travel together’. PMID:25912376
Lenton, Simon; Frank, Vibeke A; Barratt, Monica J; Dahl, Helle Vibeke; Potter, Gary R
How cannabis cultivation is dealt with under various examples of cannabis legalization or regulation is an important consideration in design of such schemes. This study aimed to (i) investigate support among current or recent cannabis growers, for various potential policy options for cannabis cultivation if prohibition were repealed, and (ii) explore the support for these options across countries, scale of growing operations, demographics, drug use and cannabis supply involvement variables. This study utilized data from the online web survey of largely 'small-scale' cannabis cultivators, aged 18yrs and over, in eleven countries conducted by the Global Cannabis Cultivation Research Consortium (GCCRC). Data from 1722 current and recent cannabis growers in Australia, Denmark and the UK, who were all asked about policy, were included in the analysis. It investigated support for various frameworks for cultivation: (no regulation (free market); adult only; growing licenses; restrictions on plant numbers; licensed business-only sale; approved commercial growing; etc.). Among current growers, support for these options were compared across countries, across scale of growing operations, and by demographics, drug use and crime variables. Although there were some between country differences in support for the various policy options, what was striking was the similarity of the proportions for each of the eight most popular policy options. Among current growers, many of these positions were predicted by demographic, drug use and cannabis growing variables which were conceptually congruent with these positions. The results have relevance for the provisions regarding cannabis cultivation in the design of new non-prohibitionist models of cannabis which are increasingly under consideration. It should be of interest to policy makers, drug policy researchers, law enforcement and cannabis cultivators. Copyright © 2014 Elsevier B.V. All rights reserved.
Full Text Available Numerous studies show the existence of a high prevalence of cannabis use among patients with psychosis. However, the differences between men and women who debut with a first episode of psychosis (FEP regarding cannabis use have not been largely explored. The aim of this study was to identify the specific sex factors and differences in clinical evolution associated with cannabis use.Sociodemographic characteristics at baseline were considered in our sample of FEP patients to find differences depending on sex and the use of cannabis. Clinical, functional and neurocognitive variables at baseline, 1-year, and 3-years follow-up were also explored.A total of 549 patients, of whom 43% (N = 236 were cannabis users, 79% (N = 186 male and 21% (N = 50 female, were included in the study. There was a clear relationship between being male and being a user of cannabis (OR = 5.6. Cannabis users were younger at illness onset. Longitudinal analysis showed that women significantly improved in all three dimensions of psychotic symptoms, both in the subgroup of cannabis users and in the non-users subgroup. Conversely, subgroups of men did not show improvement in the negative dimension. In cognitive function, only men presented a significant time by group interaction in processing speed, showing a greater improvement in the subgroup of cannabis users.Despite knowing that there is a relationship between cannabis use and psychosis, due to the high prevalence of cannabis use among male FEP patients, the results showed that there were very few differences in clinical and neurocognitive outcomes between men and women who used cannabis at the start of treatment compared to those who did not.
Waissengrin, Barliz; Urban, Damien; Leshem, Yasmin; Garty, Meital; Wolf, Ido
The use of the cannabis plant (Cannabis sativa L.) for the palliative treatment of cancer patients has been legalized in multiple jurisdictions including Israel. Yet, not much is currently known regarding the efficacy and patterns of use of cannabis in this setting. To analyze the indications for the administration of cannabis among adult Israeli cancer patients and evaluate its efficacy. Efficacy and patterns of use of cannabis were evaluated using physician-completed application forms, medical files, and a detailed questionnaire in adult cancer patients treated at a single institution. Of approximately 17,000 cancer patients seen, 279 (cannabis from an authorized institutional oncologist. The median age of cannabis users was 60 years (range 19-93 years), 160 (57%) were female, and 234 (84%) had metastatic disease. Of 151 (54%) patients alive at six months, 70 (46%) renewed their cannabis permit. Renewal was more common among younger patients and those with metastatic disease. Of 113 patients alive and using cannabis at one month, 69 (61%) responded to the detailed questionnaire. Improvement in pain, general well-being, appetite, and nausea were reported by 70%, 70%, 60%, and 50%, respectively. Side effects were mild and consisted mostly of fatigue and dizziness. Cannabis use is perceived as highly effective by some patients with advanced cancer and its administration can be regulated, even by local authorities. Additional studies are required to evaluate the efficacy of cannabis as part of the palliative treatment of cancer patients. Copyright © 2015 American Academy of Hospice and Palliative Medicine. Published by Elsevier Inc. All rights reserved.
Brunt, Tibor M; van Genugten, Marianne; Höner-Snoeken, Kathrin; van de Velde, Marco J; Niesink, Raymond J M
In The Netherlands, pharmaceutical-grade cultivated cannabis is distributed for medicinal purposes as commissioned by the Ministry of Health. Few studies have thus far described its therapeutic efficacy or subjective (adverse) effects in patients. The aims of this study are to assess the therapeutic satisfaction within a group of patients using prescribed pharmaceutical-grade cannabis and to compare the subjective effects among the available strains with special focus on their delta-9-tetrahydrocannabinol and cannabidiol content. In a cross-sectional and natural design, users of pharmaceutical-grade cannabis were investigated with questionnaires. Medical background of the patients was asked as well as experienced therapeutic effects and characteristics of cannabis use. Subjective effects were measured with psychometric scales and used to compare among the strains of cannabis used across this group of patients. One hundred two patients were included; their average age was 53 years and 76% used it for more than a year preceding this study. Chronic pain (53%; n = 54) was the most common medical indication for using cannabis followed by multiple sclerosis (23%; n = 23), and 86% (n = 88) of patients (almost) always experienced therapeutic satisfaction when using pharmaceutical cannabis. Dejection, anxiety, and appetite stimulation were found to differ among the 3 strains of cannabis. These results show that patients report therapeutic satisfaction with pharmaceutical cannabis, mainly pain alleviation. Some subjective effects were found to differ among the available strains of cannabis, which is discussed in relation to their different tetrahydrocannabinol/cannabidiol content. These results may aid in further research and critical appraisal for medicinally prescribed cannabis products.
Baker, Amanda L; Hides, Leanne; Lubman, Dan I
users of cannabis and those with more chronic mental disorders. Specific recommendations regarding the type and length of specific psychological treatments cannot be made at this time, although motivational interviewing and cognitive-behavioral therapy approaches appear most promising. (c) 2010 Physicians Postgraduate Press, Inc.
Lal, Simon; Prasad, Neeraj; Ryan, Manijeh; Tangri, Sabrena; Silverberg, Mark S; Gordon, Allan; Steinhart, Hillary
Experimental evidence suggests the endogenous cannabinoid system may protect against colonic inflammation, leading to the possibility that activation of this system may have a therapeutic role in inflammatory bowel disease (IBD). Medicinal use of cannabis for chronic pain and other symptoms has been reported in a number of medical conditions. We aimed to evaluate cannabis use in patients with IBD. One hundred patients with ulcerative colitis (UC) and 191 patients with Crohn's disease (CD) attending a tertiary-care outpatient clinic completed a questionnaire regarding current and previous cannabis use, socioeconomic factors, disease history and medication use, including complimentary alternative medicines. Quality of life was assessed using the short-inflammatory bowel disease questionnaire. A comparable proportion of UC and CD patients reported lifetime [48/95 (51%) UC vs. 91/189 (48%) CD] or current [11/95 (12%) UC vs. 30/189 (16%) CD] cannabis use. Of lifetime users, 14/43 (33%) UC and 40/80 (50%) CD patients have used it to relieve IBD-related symptoms, including abdominal pain, diarrhoea and reduced appetite. Patients were more likely to use cannabis for symptom relief if they had a history of abdominal surgery [29/48 (60%) vs. 24/74 (32%); P=0.002], chronic analgesic use [29/41 (71%) vs. 25/81 (31%); Pmedicine use [36/66 (55%) vs. 18/56 (32%); P=0.01] and a lower short inflammatory bowel disease questionnaire score (45.1±2.1 vs. 50.3±1.5; P=0.03). Patients who had used cannabis [60/139 (43%)] were more likely than nonusers [13/133 (10%); Pcannabis for IBD. Cannabis use is common amongst patients with IBD for symptom relief, particularly amongst those with a history of abdominal surgery, chronic abdominal pain and/or a low quality of life index. The therapeutic benefits of cannabinoid derivatives in IBD may warrant further exploration.
Full Text Available Objective: There are very few data about the epidemiology of hepatitis B virus (HBV, hepatitis C virus (HCV and HIV infections in drug addicts in Turkey, whereas several countries have a developed surveillance systems to monitor the spread of HBV, HCV and HIV infections in drug users. In this study, HBV, HCV and HIV prevalence in cannabis and opioid addicts were investigated. Materials and Methods: Hepatitis B surface antigen (HBsAg, anti-HBs, anti-HCV and anti-HIV tests were analyzed by enzyme-linked immunosorbent assay. The cannabis and opioid metabolites in urine samples of drug addicts were analyzed by cloned enzyme donor immunoassay. Results: This retrospective study was conducted on 276 individuals with a mean age of 28.89±10.49 years. HBsAg, anti-HBs and anti-HCV prevalence in drug addicts was found to be 4%, 52.3% and 7.9%, respectively. In all the drug addicts, anti-HIV test was negative. Whereas the rate of HBsAg among cannabis users (8.8% was higher than opioid (4.1% and both cannabis and opioid users (1.4%, the difference was not statistically significant. Although anti-HCV positivity among cannabis users was not detected, 6.4% of opioid users and 15.9% of both cannabis and opioid users were anti-HCV positive (p=0.009. Conclusion: This study showed that HCV infection among especially opioid users and both cannabis and opioid users was a problem. Understanding of local status in HBV, HCV and HIV infections is crucial for developing prevention and geographical strategies for these infections.
Cervený, J.; van Ours, J.C.; Chomynova, Pavla; Mravcik, Viktor
This paper examines the effect of a change in drugs policy on the age of onset of cannabis use. We use 2012 survey data from the Czech Republic where in 2010 a law was introduced decriminalizing personal possession of small quantities of several illicit drugs, including cannabis. We estimate the
Colizzi, Marco; Iyegbe, Conrad; Powell, John; Ursini, Gianluca; Porcelli, Annamaria; Bonvino, Aurora; Taurisano, Paolo; Romano, Raffaella; Masellis, Rita; Blasi, Giuseppe; Morgan, Craig; Aitchison, Katherine; Mondelli, Valeria; Luzi, Sonija; Kolliakou, Anna; David, Anthony; Murray, Robin M; Bertolino, Alessandro; Di Forti, Marta
Both cannabis use and the dopamine receptor (DRD2) gene have been associated with schizophrenia, psychosis-like experiences, and cognition. However, there are no published data investigating whether genetically determined variation in DRD2 dopaminergic signaling might play a role in individual susceptibility to cannabis-associated psychosis. We genotyped (1) a case-control study of 272 patients with their first episode of psychosis and 234 controls, and also from (2) a sample of 252 healthy subjects, for functional variation in DRD2, rs1076560. Data on history of cannabis use were collected on all the studied subjects by administering the Cannabis Experience Questionnaire. In the healthy subjects' sample, we also collected data on schizotypy and cognitive performance using the Schizotypal Personality Questionnaire and the N-back working memory task. In the case-control study, we found a significant interaction between the rs1076560 DRD2 genotype and cannabis use in influencing the likelihood of a psychotic disorder. Among cannabis users, carriers of the DRD2, rs1076560, T allele showed a 3-fold increased probability to suffer a psychotic disorder compared with GG carriers (OR = 3.07; 95% confidence interval [CI]: 1.22-7.63). Among daily users, T carrying subjects showed a 5-fold increase in the odds of psychosis compared to GG carriers (OR = 4.82; 95% CI: 1.39-16.71). Among the healthy subjects, T carrying cannabis users had increased schizotypy compared with T carrying cannabis-naïve subjects, GG cannabis users, and GG cannabis-naïve subjects (all P ≤ .025). T carrying cannabis users had reduced working memory accuracy compared with the other groups (all P ≤ .008). Thus, variation of the DRD2, rs1076560, genotype may modulate the psychosis-inducing effect of cannabis use. © The Author 2015. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: email@example.com.
Palali, A.; van Ours, J.C.
Abstract: In the Netherlands cannabis use is quasi-legalized. Small quantities of cannabis can be bought in cannabis-shops. We investigate how the distance to the nearest cannabis- shop affects the age of onset of cannabis use. We use a Mixed Proportional Hazard rate framework to take account of
Avery N Gilbert
Full Text Available The smell of marijuana (Cannabis sativa L. is of interest to users, growers, plant breeders, law enforcement and, increasingly, to state-licensed retail businesses. The numerous varieties and strains of Cannabis produce strikingly different scents but to date there have been few, if any, attempts to quantify these olfactory profiles directly. Using standard sensory evaluation techniques with untrained consumers we have validated a preliminary olfactory lexicon for dried cannabis flower, and characterized the aroma profile of eleven strains sold in the legal recreational market in Colorado. We show that consumers perceive differences among strains, that the strains form distinct clusters based on odor similarity, and that strain aroma profiles are linked to perceptions of potency, price, and smoking interest.
DiVerdi, Joseph A.
The smell of marijuana (Cannabis sativa L.) is of interest to users, growers, plant breeders, law enforcement and, increasingly, to state-licensed retail businesses. The numerous varieties and strains of Cannabis produce strikingly different scents but to date there have been few, if any, attempts to quantify these olfactory profiles directly. Using standard sensory evaluation techniques with untrained consumers we have validated a preliminary olfactory lexicon for dried cannabis flower, and characterized the aroma profile of eleven strains sold in the legal recreational market in Colorado. We show that consumers perceive differences among strains, that the strains form distinct clusters based on odor similarity, and that strain aroma profiles are linked to perceptions of potency, price, and smoking interest. PMID:29401526
Trigo, Jose M; Soliman, Alexandra; Staios, Gregory; Quilty, Lena; Fischer, Benedikt; George, Tony P; Rehm, Jürgen; Selby, Peter; Barnes, Allan J; Huestis, Marilyn A; Le Foll, Bernard
Cannabis is the most commonly used illicit drug; a substantial minority of users develop dependence. The current lack of pharmacological treatments for cannabis dependence warrants the use of novel approaches and further investigation of promising pharmacotherapy. In this case series, we assessed the use of self-titrated dosages of Sativex (1:1, Δ-tetrahydrocannabinol [THC]/cannabidiol [CBD] combination) and motivational enhancement therapy and cognitive behavioral therapy (MET/CBT) for the treatment of cannabis dependence among 5 treatment-seeking community-recruited cannabis-dependent subjects. Participants underwent a 3-month open-label self-titration phase with Sativex (up to 113.4 of THC/105 mg of CBD) and weekly MET/CBT, with a 3-month follow-up. Sativex was well-tolerated by all participants (average dosage 77.5 THC/71.7 mg CBD). The combination of Sativex and MET/CBT reduced the amount of cannabis use and progressively reduced craving and withdrawal scores. THC/CBD metabolite concentration indicated reduced cannabis use and compliance with medication. In summary, this pilot study found that with Sativex in combination with MET/CBT reduced cannabis use while preventing increases in craving and withdrawal in the 4 participants completing the study. Further systematic exploration of Sativex as a pharmacological treatment option for cannabis dependence should be performed.
Kazour, F; Awaida, C; Souaiby, L; Richa, S
Cannabis use is very frequent in bipolar disorder and has been found to increase the duration and frequency of manic symptoms while decreasing those of depression. Bipolar patients who use cannabis were shown to have poorer compliance to treatment, more symptoms that are psychotic and a worse prognosis than patients who do not. In this study, we have evaluated the importance of cannabis use among bipolar patients admitted to the Psychiatric Hospital of the Cross, Lebanon (Hôpital Psychiatrique de la Croix [HPC]) as well as the clinical differences between cannabis users and non-users. Over a period of 13 months, we recruited the patients admitted to HPC for bipolar disorder according to the MINI DSM-IV criteria. These patients were screened for substance abuse/dependence and were accordingly divided into 2 groups: cannabis users and cannabis non-users. Both groups were interviewed by a medical student and asked to answer the following questionnaires: the MINI DSM-IV, the Young Mania Rating Scale (YMRS) for evaluating manic episodes, the Montgomery and Åsberg Depression Rating Scale (MADRS) for evaluating depressive episodes, the Scale for the Assessment of Positive Symptoms (SAPS) to assess psychotic symptoms associated to the bipolar disorder, and the Cannabis Abuse Screening Test (CAST) for evaluating the importance of cannabis consumption. The study's exclusion criteria were the following: diagnosis of a confusional state, schizophrenia and other psychotic disorders, dementia, age less than 18 years old or superior to 85 years old, and non-cooperation. Among the 100 bipolar patients included in the study, 27 (27 %) were cannabis users. Eight of these 27 patients were first admitted to HPC for substance abuse and then included in the study after a bipolar disorder was diagnosed according to the MINI DSM-IV criteria. Cannabis use was found to be more prevalent in young males with a mean age of 20.3 years old at the first contact with the substance
Full Text Available Previous studies have mostly shown positive effects of cannabis use on cognition in patients with schizophrenia, which could reflect lower neurocognitive vulnerability. There are however no studies comparing whether such cognitive differences have neuronal correlates. Thus, the aim of the present study was to compare whether patients with previous cannabis use differ in brain activation from patients who has never used cannabis. The patients groups were compared on the ability to up-regulate an effort mode network during a cognitive task and down-regulate activation in the same network during a task-absent condition. Task-present and task-absent brain activation was measured by functional magnetic resonance neuroimaging (fMRI. Twenty-six patients with a DSM-IV and ICD-10 diagnosis of schizophrenia were grouped into a previous cannabis user group and a no-cannabis group. An auditory dichotic listening task with instructions of attention focus on either the right or left ear stimulus was used to tap verbal processing, attention and cognitive control, calculated as an aggregate score. When comparing the two groups, there were remaining activations in the task-present condition for the cannabis group, not seen in the no-cannabis group, while there was remaining activation in the task-absent condition for the no-cannabis group, not seen in the cannabis group. Thus, the patients with previous cannabis use showed increased activation in an effort mode network and decreased activation in the default mode network as compared to the no-cannabis group. It is concluded that the present study show some differences in brain activation to a cognitively challenging task between previous cannabis and no-cannabis schizophrenia patients.
Brian Frazier Thomas
Full Text Available Cannabis is classified as a schedule I controlled substance by the US Drug Enforcement Agency, meaning that it has no medicinal value. Production is legally restricted to a single supplier at the University of Mississippi, and distribution to researchers is tightly controlled. However, a majority of the population is estimated to believe that cannabis has legitimate medical or recreational value, numerous states have legalized or decriminalized possession to some degree, and the federal government does not strictly enforce its law and is considering rescheduling. The explosive increase in open sale and use of herbal cannabis and its products has occurred with widely variable and in many cases grossly inadequate quality control at all levels—growing, processing, storage, distribution, and use. This paper discusses elements of the analytical and regulatory system that need to be put in place to ensure standardization for the researcher and to reduce the hazards of contamination, overdosing and underdosing for the end-user.
Thomas, Brian F.; Pollard, Gerald T.
Cannabis is classified as a schedule I controlled substance by the US Drug Enforcement Agency, meaning that it has no medicinal value. Production is legally restricted to a single supplier at the University of Mississippi, and distribution to researchers is tightly controlled. However, a majority of the population is estimated to believe that cannabis has legitimate medical or recreational value, numerous states have legalized or decriminalized possession to some degree, and the federal government does not strictly enforce its law and is considering rescheduling. The explosive increase in open sale and use of herbal cannabis and its products has occurred with widely variable and in many cases grossly inadequate quality control at all levels—growing, processing, storage, distribution, and use. This paper discusses elements of the analytical and regulatory system that need to be put in place to ensure standardization for the researcher and to reduce the hazards of contamination, overdosing, and underdosing for the end-user. PMID:27630566
Brañas, Antía; Barrigón, María L; Garrido-Torres, Nathalia; Perona-Garcelán, Salvador; Rodriguez-Testal, Juan F; Lahera, Guillermo; Ruiz-Veguilla, Miguel
The aim of this study was to investigate the relationship between psychotic-like experiences (PLEs) assessed using the Community Assessment of Psychic Experience (CAPE) questionnaire and the pattern of cannabis use in a non-clinical sample collected by snowball sampling. Our sample was composed of 204 subjects, distributed into three groups by their cannabis use pattern: 68 were non-cannabis users, 40 were moderate cannabis users and 96 were daily cannabis users. We assessed the psychotic experiences in each group with the CAPE questionnaire; and then controlled for the effect of possible confounding factors like sex, age, social exclusion, age of onset of cannabis use, alcohol use and other drug use. We found a significant quadratic association between the frequency of cannabis use and positive (β = -1.8; p = 0.004) and negative dimension scores (β = -1.2; p = 0.04). The first-rank and mania factors showed a significant quadratic association (p < 0.05), while the voices factor showed a trend (p = 0.07). Scores for the different groups tended to maintain a U-shape in their values for the different factors. When we adjusted for gender, age, social exclusion, age of onset of cannabis use, and use of alcohol and other drugs, only the first-rank experiences remained significant. We found there was a U-shaped curve in the association between cannabis use and the positive and negative dimensions of the CAPE score. We also found this association in mania and first-rank experiences. © The Author(s) 2016.
Westfall, Rachel E; Janssen, Patricia A; Lucas, Philippe; Capler, Rielle
A majority of women experience some nausea and/or vomiting during pregnancy. This condition can range from mild nausea to extreme nausea and vomiting, with 1-2% of women suffering from the life-threatening condition hyperemesis gravidarum. Cannabis (Cannabis sativa) may be used therapeutically to mitigate pregnancy-induced nausea and vomiting. This paper presents the results of a survey of 84 female users of medicinal cannabis, recruited through two compassion societies in British Columbia, Canada. Of the seventy-nine respondents who had experienced pregnancy, 51 (65%) reported using cannabis during their pregnancies. While 59 (77%) of the respondents who had been pregnant had experienced nausea and/or vomiting of pregnancy, 40 (68%) had used cannabis to treat the condition, and of these respondents, 37 (over 92%) rated cannabis as 'extremely effective' or 'effective.' Our findings support the need for further investigations into cannabis therapy for severe nausea and vomiting during pregnancy.
van Ours, J.C.; Williams, J.
This paper investigates whether cannabis use leads to worse mental health. To do so, we account for common unobserved factors affecting mental health and cannabis consumption by modeling mental health jointly with the dynamics of cannabis use. Our main finding is that using cannabis increases the
Underner, M; Urban, T; Perriot, J; de Chazeron, I; Meurice, J-C
Cannabis is the most commonly smoked illicit substance in the world. It can be smoked alone in plant form (marijuana) but it is mainly smoked mixed with tobacco. The combined smoking of cannabis and tobacco is a common-place phenomenon in our society. However, its use is responsible for severe pulmonary consequences. The specific impact of smoking cannabis is difficult to assess precisely and to distinguish from the effect of tobacco. Marijuana smoke contains polycyclic aromatic hydrocarbons and carcinogens at higher concentration than tobacco smoke. Cellular, tissue, animal and human studies, and also epidemiological studies, show that marijuana smoke is a risk factor for lung cancer. Cannabis exposure doubles the risk of developing lung cancer. This should encourage clinicians to identify cannabis use and to offer patients support in quitting. Copyright © 2014 SPLF. Published by Elsevier Masson SAS. All rights reserved.
Corroon, James M; Mischley, Laurie K; Sexton, Michelle
Background The use of medical cannabis is increasing, most commonly for pain, anxiety and depression. Emerging data suggest that use and abuse of prescription drugs may be decreasing in states where medical cannabis is legal. The aim of this study was to survey cannabis users to determine whether they had intentionally substituted cannabis for prescription drugs. Methods A total of 2,774 individuals were a self-selected convenience sample who reported having used cannabis at least once in the previous 90 days. Subjects were surveyed via an online anonymous questionnaire on cannabis substitution effects. Participants were recruited through social media and cannabis dispensaries in Washington State. Results A total of 1,248 (46%) respondents reported using cannabis as a substitute for prescription drugs. The most common classes of drugs substituted were narcotics/opioids (35.8%), anxiolytics/benzodiazepines (13.6%) and antidepressants (12.7%). A total of 2,473 substitutions were reported or approximately two drug substitutions per affirmative respondent. The odds of reporting substituting were 4.59 (95% confidence interval [CI], 3.87–5.43) greater among medical cannabis users compared with non-medical users and 1.66 (95% CI, 1.27–2.16) greater among those reporting use for managing the comorbidities of pain, anxiety and depression. A slightly higher percentage of those who reported substituting resided in states where medical cannabis was legal at the time of the survey (47% vs. 45%, p=0.58), but this difference was not statistically significant. Discussion These patient-reported outcomes support prior research that individuals are using cannabis as a substitute for prescription drugs, particularly, narcotics/opioids, and independent of whether they identify themselves as medical or non-medical users. This is especially true if they suffer from pain, anxiety and depression. Additionally, this study suggests that state laws allowing access to, and use of, medical
Rasmussen, Jerod; Casey, B J; van Erp, Theo G M; Tamm, Leanne; Epstein, Jeffery N; Buss, Claudia; Bjork, James M; Molina, Brooke S G; Velanova, Katerina; Mathalon, Daniel H; Somerville, Leah; Swanson, James M; Wigal, Tim; Arnold, L Eugene; Potkin, Steven G
Children diagnosed with attention-deficit/hyperactivity disorder (ADHD) are at increased risk for substance abuse. Response inhibition is a hallmark of ADHD, yet the combined effects of ADHD and regular substance use on neural networks associated with response inhibition are unknown. Task-based functional Magnetic Resonance Imaging (fMRI) data from young adults with childhood ADHD with (n = 25) and without (n = 25) cannabis use ≥ monthly in the past year were compared with a local normative comparison group (LNCG) with (n = 11) and without (n = 12) cannabis use. Go/NoGo behavioral and fMRI data were evaluated for main and interaction effects of ADHD diagnosis and cannabis use. ADHD participants made significantly more commission errors on NoGo trials than controls. ADHD participants also had less frontoparietal and frontostriatal activity, independent of cannabis use. No main effects of cannabis use on response inhibition or functional brain activation were observed. An interaction of ADHD diagnosis and cannabis use was found in the right hippocampus and cerebellar vermis, with increased recruitment of these regions in cannabis-using controls during correct response inhibition. ADHD participants had impaired response inhibition combined with less fronto-parietal/striatal activity, regardless of cannabis use history. Cannabis use did not impact behavioral response inhibition. Cannabis use was associated with hippocampal and cerebellar activation, areas rich in cannabinoid receptors, in LNCG but not ADHD participants. This may reflect recruitment of compensatory circuitry in cannabis using controls but not ADHD participants. Future studies targeting hippocampal and cerebellar-dependent function in these groups may provide further insight into how this circuitry is altered by ADHD and cannabis use.
Greiner, Christian; Chatton, Anne; Khazaal, Yasser
To investigate online self-help forums related to cannabis users who were searching for help on the Internet. We analyzed the content of 717 postings by 328 users in three online forums in terms of fields of interest and self-help mechanisms. Only English-language forums that were free of charge and without registration were investigated. The main self-help mechanisms were disclosure and symptoms, with relatively few posts concerning legal issues and social perceptions. The forums differed significantly in all fields of interest and self-help mechanisms except for social network and financial and vocational issues. Highly involved users more commonly posted on topics related to diagnosis, etiology/research, and provision of information and less commonly on those related to gratitude. Correlation analysis showed a moderate negative correlation between emotional support and illness-related aspects and between emotional support and exchange of information. Cannabis forums share similarities with other mental health forums. Posts differ according to user involvement and the specific orientation of the forum. The Internet offers a viable source of self-help and social support for cannabis users, which has potential clinical implications in terms of referring clients to specific forums. Copyright © 2017 Elsevier B.V. All rights reserved.
Griffith-Lendering, Merel Frederique Heleen
During early adolescence, there is no association between internalizing behaviour and cannabis use. There is an association between externalizing behaviour and cannabis use, where externalizing behaviour precedes cannabis use rather than the other way around. Secondly, during adolescence, there is an association between psychosis vulnerability and cannabis use, where cannabis use predicts psychosis vulnerability and vice versa, suggesting a bi-directional cascading association. Thirdly, durin...
Lamy, Francois R.; Daniulaityte, Raminta; Sheth, Amit; Nahhas, Ramzi W.; Martins, Silvia S.; Boyer, Edward W.; Carlson, Robert G.
Aims Several states in the U.S. have legalized cannabis for recreational or medical uses. In this context, cannabis edibles have drawn considerable attention after adverse effects were reported. This paper investigates Twitter users’ perceptions concerning edibles and evaluates the association edibles-related tweeting activity and local cannabis legislation. Methods Tweets were collected between May 1 and July 31, 2015, using Twitter API and filtered through the eDrugTrends/Twitris platform. A random sample of geolocated tweets was manually coded to evaluate Twitter users’ perceptions regarding edibles. Raw state proportions of Twitter users mentioning edibles were ajusted relative to the total number of Twitter users per state. Differences in adjusted proportions of Twitter users mentioning edibles between states with different cannabis legislation status were assesed via a permutation test. Results We collected 100,182 tweets mentioning cannabis edibles with 26.9% (n=26,975) containing state-level geolocation. Adjusted percentages of geolocated Twitter users posting about edibles were significantly greater in states that allow recreational and/or medical use of cannabis. The differences were statistically significant. Overall, cannabis edibles were generally positively perceived among Twitter users despite some negative tweets expressing the unreliability of edible consumption linked to variability in effect intensity and duration. Conclusion Our findings suggest that Twitter data analysis is an important tool for epidemiological monitoring of emerging drug use practices and trends. Results tend to indicate greater tweeting activity about cannabis edibles in states where medical THC and/or recreational use are legal. Although the majority of tweets conveyed positive attitudes about cannabis edibles, analysis of experiences expressed in negative tweets confirms the potential adverse effects of edibles and calls for educating edibles-naïve users, improving
Full Text Available Abstract Although little evidence supports cannabis-induced amotivational syndrome, sources continue to assert that the drug saps motivation 1, which may guide current prohibitions. Few studies report low motivation in chronic users; another reveals that they have higher subjective wellbeing. To assess differences in motivation and subjective wellbeing, we used a large sample (N = 487 and strict definitions of cannabis use (7 days/week and abstinence (never. Standard statistical techniques showed no differences. Robust statistical methods controlling for heteroscedasticity, non-normality and extreme values found no differences in motivation but a small difference in subjective wellbeing. Medical users of cannabis reporting health problems tended to account for a significant portion of subjective wellbeing differences, suggesting that illness decreased wellbeing. All p-values were above p = .05. Thus, daily use of cannabis does not impair motivation. Its impact on subjective wellbeing is small and may actually reflect lower wellbeing due to medical symptoms rather than actual consumption of the plant.
The aim of the present study was to investigate the stability of cannabinoids in cannabis resin slabs and cannabis extracts upon long-term storage. The levels of tetrahydrocannabinol (THC), cannabinol (CBN), cannabidiol (CBD) and cannabigerol (CBG) on both neutral and acidic form were measured...... stored in extracted form at room temperature the degradation rate of acidic THC increased significantly relative to resin material with concentration halve-lives of 35 and 91 days in daylight and darkness, respectively. Once cannabis material is extracted into organic solvents, care should be taken...
Ritter, Catherine; Broers, Barbara; Elger, Bernice S
Several studies suggest a high prevalence of cannabis use before and during imprisonment, but subjective perspectives of detainees and staff towards its use in prison are lacking. This issue was explored in the framework of an observational study addressing tobacco use in three Swiss prisons in 2009 and 2010 that involved multiple strands (quantitative and qualitative components). This article presents qualitative data on cannabis use collected in one of the settings. We used in-depth semi-structured interviews with both detainees and staff to explore their attitudes towards cannabis in one post-trial male Swiss prison. We performed specific coding and thematic analysis for cannabis with the support of ATLAS.ti, compared detainees' and staff's opinions, and considered the results with regard to drug policy in prison in general. 58 participants (31 male offenders, mean age 35 years, and 27 prison staff, mean age 46 years, 33% female) were interviewed. Detainees estimated the current use of cannabis use to be as high as 80%, and staff 50%. Participants showed similar opinions on effects of cannabis use that were described both at individual and institutional levels: analgesic, calming, self-help to go through the prison experience, relieve stress, facilitate sleep, prevent violence, and social pacifier. They also mentioned negative consequences of cannabis use (sleepiness, decreased perception of danger and social isolation), and dissatisfaction regarding the ongoing ambiguous situation where cannabis is forbidden but detection in the urine was not sanctioned. However, the introduction of a more restrictive regulation induced fear of violence, increased trafficking and a shift to other drug use. Although illegal, cannabis use is clearly involved in daily life in prison. A clearer and comprehensive policy addressing cannabis is needed, including appropriate measures tailored to individual users. To sustain a calm and safe environment in prison, means other than
Hakkarainen, Pekka; Frank, Vibeke Asmussen; Barratt, Monica J; Dahl, Helle Vibeke; Decorte, Tom; Karjalainen, Karoliina; Lenton, Simon; Potter, Gary; Werse, Bernd
The production and consumption of cannabis for the treatment of medical conditions is of increasing importance internationally; however, research on different aspects of the phenomenon is still scarce. In this article, we report findings from a cross-cultural study of small-scale cannabis cultivation for medical purposes. This kind of comparative study has not been done previously. The data were gathered with a help of web surveys conducted by the Global Cannabis Cultivation Research Consortium (GCCRC) in Australia, Belgium, Denmark, Finland, Germany and the UK (N=5313). In the analysis we compare reports of medical motives, for what conditions cannabis is used, whether users have diagnoses for these conditions and whether the use of cannabis been recommended as a treatment of those conditions by a medical doctor. Descriptive statistics are used to show the main commonalities and noteworthy disparities across different countries. Findings from countries were quite similar, even though several national differences in details were found. Growing cannabis for medical purposes was widespread. The majority of medical growers reported cultivating cannabis for serious conditions. Most of them did have a formal diagnosis. One fifth had got a recommendation from their doctor, but in most cases cannabis use was self-medication which was not discussed with their doctors. There is a wider demand for licit access for medical cannabis than currently available in these countries. Ideologically, medical growers can be seen distancing themselves from both the legal and illicit drug markets. From a harm reduction perspective, it is worrying that, in the context of present health and control policies in these countries, many medical growers are using cannabis to treat serious medical conditions without proper medical advice and doctor's guidance. Copyright © 2014 Elsevier B.V. All rights reserved.
ElSohly, Mahmoud A; Radwan, Mohamed M; Gul, Waseem; Chandra, Suman; Galal, Ahmed
Cannabis (Cannabis sativa, or hemp) and its constituents-in particular the cannabinoids-have been the focus of extensive chemical and biological research for almost half a century since the discovery of the chemical structure of its major active constituent, Δ 9 -tetrahydrocannabinol (Δ 9 -THC). The plant's behavioral and psychotropic effects are attributed to its content of this class of compounds, the cannabinoids, primarily Δ 9 -THC, which is produced mainly in the leaves and flower buds of the plant. Besides Δ 9 -THC, there are also non-psychoactive cannabinoids with several medicinal functions, such as cannabidiol (CBD), cannabichromene (CBC), and cannabigerol (CBG), along with other non-cannabinoid constituents belonging to diverse classes of natural products. Today, more than 560 constituents have been identified in cannabis. The recent discoveries of the medicinal properties of cannabis and the cannabinoids in addition to their potential applications in the treatment of a number of serious illnesses, such as glaucoma, depression, neuralgia, multiple sclerosis, Alzheimer's, and alleviation of symptoms of HIV/AIDS and cancer, have given momentum to the quest for further understanding the chemistry, biology, and medicinal properties of this plant.This contribution presents an overview of the botany, cultivation aspects, and the phytochemistry of cannabis and its