The relationship between cannabis use and other substance use in the general population

Cannabis use disorders and outcome of admission to intensive care: A retrospective multi-centre cohort study

PURPOSE

To identify factors associated with cannabinoid use among patients admitted to ICU and its impact on survival.

METHODS

A cohort of adult patients admitted to four public Australian ICUs was assembled. Individuals with mental and behavioural disorders related to cannabinoids were identified using ICD10-AM codes.

RESULTS

Of a cohort of 34,680 admissions among 28,689 adults, 292 (0.8%) had an associated diagnosis related to cannabinoids, of which 66% were classified as harmful use, 26% as dependence syndrome/withdrawal state, 4% as psychosis/delirium, and 4% as acute intoxication. Patients with cannabinoid-use disorders were more likely to be male (73%), tended to be younger (36 vs 62 years), with fewer comorbidities and lesser severity of disease. ICU LOS was longer for those with cannabinoid-use disorders (2 vs 1 days; p < 0.0001). Patients with cannabinoid-use disorders had lower 90-day case-fatality (6% vs. 10%; p = 0.034), however no significant effect on mortality was present after adjustment for severity of illness, age, and chronic comorbidities (p = 1.0).

CONCLUSION

Cannabinoid-use disorders were present in 0.8% of ICU admissions in our region and were associated with increased ICU length of stay. Further studies are needed to examine cannabinoids as contributors to and modifiers of critical illness.

Resting state functional connectivity in dependent cannabis users: The moderating role of cannabis attitudes

BACKGROUND

The global increase in lenient cannabis policy has been paralleled by reduced harm perception, which has been associated with cannabis use initiation and persistent use. However, it is unclear how cannabis attitudes might affect the brain processes underlying cannabis use.

METHODS

Resting state functional connectivity (RSFC) within and between the executive control network (ECN), salience network (SN), and default mode network (DMN) was assessed in 110 near-daily cannabis users with cannabis use disorder (CUD) and 79 controls from The Netherlands and Texas, USA. Participants completed a questionnaire assessing the perceived benefits and harms of cannabis use from their personal, friends-family's, and country-state's perspectives and reported on their cannabis use (gram/week), CUD severity, and cannabis-related problems.

RESULTS

RSFC within the dorsal SN was lower in cannabis users than controls, while no group differences in between-network RSFC were observed. Furthermore, heavier cannabis use was associated with lower dorsal SN RSFC in the cannabis group. Perceived benefits and harms of cannabis - from personal, friends-family's, and country-state's perspectives - moderated associations of cannabis use, CUD severity, and cannabis use-related problems with within-network RSFC of the SN, ECN, and DMN. Personal perceived benefits and country-state perceived harms moderated the association between CUD severity and RSFC between the ventral and dorsal DMN.

CONCLUSIONS

This study highlights the importance of considering individual differences in the perceived harms and benefits of cannabis use as a factor in the associations between brain functioning and cannabis use, CUD severity, and cannabis use-related problems.

Unlocking the Healing Potential: Cannabinoids in Spine Surgery for Pain Relief and Recovery

» Cannabinoids, such as D9-tetrahydrocannabinol and cannabidiol, interact with endocannabinoid receptors in the central nervous system and immune system, potentially offering pain relief. The entourage effect, resulting from the interaction of multiple cannabis components, may enhance therapeutic impact and efficacy, making them promising candidates for exploring pain relief in spine operations, known to be among the most painful operative procedures.» The use of cannabinoids in pain management requires careful consideration of safety, including their cognitive and psychomotor effects, potential cardiovascular risks, risk of dependence, mental health implications, and drug interactions.» Few studies have analyzed cannabinoid use in relation to spine surgery, with variable results reported, indicating possible effects on reoperation rates, mortality, complications, postoperative opioid use, and length of hospital stay.» Current knowledge gaps exist in the understanding of cannabinoid effects on spine surgery, including the exploration of different administration routes, timing, dosage, and specific outcomes. In addition, mechanistic explanations for the observed results are lacking.» Ethical considerations related to informed consent, medical expertise, societal impact, and legal compliance must also be thoroughly addressed when considering the utilization of cannabinoids in spinal pathologies and back pain treatment.

Weight loss outcomes are not compromised in bariatric patients using cannabis

BACKGROUND

The legalization of cannabis in several states has led to increased documented use in the population. Bariatric surgery patients are no exception with estimates of anywhere from 6 to 8%. Cannabis is known to be associated with increased appetite, mood disorders, hyperphagia, and rarely, hyperemesis, which can potentially affect post-surgical weight loss. We aim to study the differences in bariatric surgery outcomes between cannabis users and non-users.

METHODS

A retrospective review identified patients undergoing bariatric surgery. Patients were divided into two groups, cannabis users (CU) and non-cannabis users (non-CU). Cannabis users (defined as using at least once weekly) and a group of non-users were called to obtain additional information. Primary outcome was weight loss. Secondary outcomes included incidence of post-operative nausea and vomiting (PONV), length of stay (LOS), readmission, and need for additional intervention.

RESULTS

A cohort of 364 sleeve gastrectomy patients met inclusion criteria, 31 (8.5%) CU and 333 (91.5%) non-CU. There was no difference in EWL between CU and non-CU at 1 week, 1 month, 3 months, 6 months, 9 months, 1 year, and 2 years. However, the CU group trended towards greater EWL at 3 years (52.9% vs. 38.1%, p = 0.094) and at 5 years (49.8% vs. 32.7%, p = 0.068). There were no significant differences between CU and non-CU with respect to either incidence or severity of PONV at one year after surgery or longer follow-up.

CONCLUSION

Cannabis users did not experience inferior weight loss after bariatric surgery despite common assumptions that appetite stimulation can lead to suboptimal weight loss outcomes. Our findings add to other work challenging this dogma. Larger, long-term, multicenter studies are warranted.

The CannTeen Study: Cannabis use disorder, depression, anxiety, and psychotic-like symptoms in adolescent and adult cannabis users and age-matched controls

BACKGROUND

Adolescence is characterised by psychological and neural development. Cannabis harms may be accentuated during adolescence. We hypothesised that adolescents would be more vulnerable to the associations between cannabis use and mental health and addiction problems than adults.

METHOD

As part of the 'CannTeen' study, we conducted a cross-sectional analysis. There were 274 participants: split into groups of adolescent users (n = 76; 16-17 years old) and controls (n = 63), and adult users (n = 71; 26-29 years old) and controls (n = 64). Among users, cannabis use frequency ranged from 1 to 7 days/week, while controls had 0-10 lifetime exposures to cannabis. Adolescent and adult cannabis users were matched on cannabis use frequency (mean=4 days/week). We measured Diagnostic and Statistical Manual (DSM-5) Cannabis Use Disorder (CUD), Beck Depression Inventory, Beck Anxiety Inventory and Psychotomimetic States Inventory-adapted.

RESULTS

After adjustment for covariates, adolescent users were more likely to have severe CUD than adult users (odd ratio = 3.474, 95% confidence interval (CI) = 1.501-8.036). Users reported greater psychotic-like symptoms than controls (b = 6.004, 95% CI = 1.211-10.796) and adolescents reported greater psychotic-like symptoms than adults (b = 5.509, 95% CI = 1.070-9.947). User-group was not associated with depression or anxiety. No significant interactions between age-group and user-group were identified. Exploratory analyses suggested that cannabis users with severe CUD had greater depression and anxiety levels than cannabis users without severe CUD.

CONCLUSION

Adolescent cannabis users are more likely than adult cannabis users to have severe CUD. Adolescent cannabis users have greater psychotic-like symptoms than adult cannabis users and adolescent controls, through an additive effect. There was no evidence of an amplified vulnerability to cannabis-related increases in subclinical depression, anxiety or psychotic-like symptoms in adolescence. However, poorer mental health was associated with the presence of severe CUD.

Diminished Structural Brain Integrity in Long-term Cannabis Users Reflects a History of Polysubstance Use

BACKGROUND

Cannabis legalization and use are outpacing our understanding of its long-term effects on brain and behavior, which is fundamental for effective policy and health practices. Existing studies are limited by small samples, cross-sectional measures, failure to separate long-term from recreational use, and inadequate control for other substance use. Here, we address these limitations by determining the structural brain integrity of long-term cannabis users in the Dunedin Study, a longitudinal investigation of a population-representative birth cohort followed to midlife.

METHODS

We leveraged prospective measures of cannabis, alcohol, tobacco, and other illicit drug use in addition to structural neuroimaging in 875 study members at age 45 to test for differences in both global and regional gray and white matter integrity between long-term cannabis users and lifelong nonusers. We additionally tested for dose-response associations between continuous measures of cannabis use and brain structure, including careful adjustments for use of other substances.

RESULTS

Long-term cannabis users had a thinner cortex, smaller subcortical gray matter volumes, and higher machine learning-predicted brain age than nonusers. However, these differences in structural brain integrity were explained by the propensity of long-term cannabis users to engage in polysubstance use, especially with alcohol and tobacco.

CONCLUSIONS

These findings suggest that diminished midlife structural brain integrity in long-term cannabis users reflects a broader pattern of polysubstance use, underlining the importance of understanding comorbid substance use in efforts to curb the negative effects of cannabis on brain and behavior as well as establish more effective policy and health practices.

Could Alcohol Abuse and Dependence on Junk Foods Inducing Obesity and/or Illicit Drug Use Represent Danger to Liver in Young People with Altered Psychological/Relational Spheres or Emotional Problems?

Recent data show that young people, mainly due to the pressure of some risk factors or due to disrupted interpersonal relationships, utilise greater reward value and display greater sensitivity to the reinforcing properties of “pleasurable stimuli”, specifically in those situations in which an enhanced dopamine release is present. Alcoholic beverages, foods rich in sugar and fat, and illicit drug use are pleasurable feelings associated with rewards. Research shows that there is a link between substance abuse and obesity in brain functioning. Still, alcohol excess is central in leading to obesity and obesity-related morbidities, such as hepatic steatosis, mainly when associated with illicit drug dependence and negative eating behaviours in young people. It is ascertained that long-term drinking causes mental damage, similarly to drug abuse, but also affects liver function. Indeed, beyond the pharmacokinetic interactions of alcohol with drugs, occurring in the liver due to the same metabolic enzymes, there are also pharmacodynamic interactions of both substances in the CNS. To complicate matters, an important noxious effect of junk foods consists of inducing obesity and obesity-related NAFLD. In this review, we focus on some key mechanisms underlying the impact of these addictions on the liver, as well as those on the CNS.

Risk factors for alcohol, marijuana, and cigarette polysubstance use during adolescence and young adulthood: A 7-year longitudinal study of youth at high risk for smoking escalation

INTRODUCTION

Alcohol, nicotine, and marijuana are the three most widely used substances among adolescents and young adults, with co-use of multiple substances being common. Few longitudinal studies have examined risk factors of alcohol, marijuana, and nicotine poly-substance use. We examined frequency of alcohol, marijuana, and cigarette poly-substance use over time and how key risk factors contribute to this substance use during adolescence and young adulthood.

METHODS

Participants (N = 1263 9th and 10th graders) were oversampled for ever-smoking a cigarette at baseline from 16 Chicago-area high schools between 2004 and 2006. Many participants progressed to heavier cigarette use, as well as alcohol and marijuana use over time. Participants completed questionnaires assessing substance use and psychosocial factors at baseline, 6-, 15-, 24-, 33-months, and 5-, 6-, and 7-years.

RESULTS

Longitudinal multi-level models demonstrated that at baseline and over time, more depression symptoms, more anxiety symptoms, negative mood regulation expectancies, and lower grade point average (GPA) were each associated with more poly-substance use over time. In addition, there were a number of interaction effects of gender (e.g., depression was related to substance use in males) and developmental stage moderated these relationships.

CONCLUSIONS

Depression, anxiety, negative mood regulation expectancies, and GPA all significantly influence both initial and longitudinal levels of substance use across adolescence and young adulthood. Our findings underscore the importance of identifying and treating youth with depression and anxiety symptoms, as well as providing resources early for those struggling in school in order to help with substance use prevention and intervention efforts.

Race, psychosocial characteristics, and treatment outcomes among individuals undergoing treatment for cannabis use disorder: A latent profile analysis based on preferred method of using cannabis

INTRODUCTION

There are a wide variety of methods for using combustible cannabis which may impact an individual's pattern of use as well as their response to cannabis use disorder (CUD) treatment. Previous research has noted racial/ethnic differences in cannabis users' preferred method of use.

METHOD

The current study examined data from a randomized placebo-controlled trial of a pharmacological intervention for adults with CUD. Latent profile analysis classified participants (N = 302) based on their primary method of combustible cannabis use.

RESULTS

A four profile solution emerged which identified participants who demonstrated 1) Primarily Joint (n = 50), 2) Primarily Blunt (n = 106), 3) Mixed MoU (n = 30), and 4) Primarily Pipe (i.e., pipe or bong; n = 116) use. Profiles were compared on socio-demographic characteristics and racial differences were found among the four latent profiles as well as differences in their level of use. Cannabis users with a preference for joints were more likely to be White as compared to other racial groups. In contrast, a greater proportion of participants with a preference for blunts were African American. The Primarily Joint profile was found to have the highest cannabis relapse rate at 1-month follow-up (94%) which was significantly greater than the Mixed MoU (74%, x² = 5.06, p < .05) and Primarily Pipe (78%, x² = 9.24, p < .01) profiles. Interestingly, there was no difference in 1-Month Follow-up cannabis relapse rates between the Primarily Joint and Blunt profiles (87%, x² = 9.24, p > .05).

CONCLUSIONS

Findings suggest that treatment-seeking individuals who primarily use joints or blunts may face unique challenges that may impact cannabis abstinence. Along with other cannabis-related characteristics, an individual's preferred method of use may represent an important factor to consider in the treatment of CUD.

Cannabinoids and myocardial ischemia: Novel insights, updated mechanisms, and implications for myocardial infarction

Cannabis is the most widely trafficked and abused illicit drug due to its calming psychoactive properties. It has been increasingly recognized as having potential health benefits and relatively less adverse health effects as compared to other illicit drugs; however, growing evidence clearly indicates that cannabis is associated with considerable adverse cardiovascular events. Recent studies have linked cannabis use to myocardial infarction (MI); yet, very little is known about the underlying mechanisms. A MI is a cardiovascular disease characterized by a mismatch in the oxygen supply and demand of the heart, resulting in ischemia and subsequent necrosis of the myocardium. Since cannabis is increasingly being considered a risk factor for MI, there is a growing need for better appreciating its potential health benefits and consequences. Here, we discuss the cellular mechanisms of cannabis that lead to an increased risk of MI. We provide a thorough and critical analysis of cannabinoids' actions, which include modulation of adipocyte biology, regional fat distribution, and atherosclerosis, as well as precipitation of hemodynamic stressors relevant in the setting of a MI. By critically dissecting the modulation of signaling pathways in multiple cell types, this paper highlights the mechanisms through which cannabis may trigger life-threatening cardiovascular events. This then provides a framework for future pharmacological studies which can identify targets or develop drugs that modulate cannabis' effects on the cardiovascular system as well as other organ systems. Cannabis' impact on the autonomic outflow, vascular smooth muscle cells, myocardium, cortisol levels and other hemodynamic changes are also mechanistically reviewed.

Investigating sex differences in acute intoxication and verbal memory errors after ad libitum cannabis concentrate use

BACKGROUND

An innovative naturalistic at-home administration procedure was used to investigate sex differences in subjective drug effects and verbal memory errors after ad libitum use of high potency state legal market Δ9-tetrahydrocannabinol (THC) concentrate.

METHODS

Regular concentrate users were randomly assigned to ad libitum administration of one of two cannabis concentrate products (70 % or 90 % THC) that they purchased from a dispensary. 65 participants (N = 34 men, N = 31 women) were assessed in a mobile pharmacology lab before, immediately after, and 1 -h after ad libitum concentrate use. Plasma cannabinoids (THC, 11-OH-THC, CBD), subjective drug effects, and verbal memory errors were assessed at all three time points.

RESULTS

Although men and women exhibited similar plasma 11-OH-THC levels across time (p = .10), sex differences were found in plasma THC and CBD after legal market concentrate use, with men displaying significantly higher levels of plasma THC and CBD immediately after cannabis concentrate use (plasma THC [ng/mL]: M_men = 489.88, M_women = 135.08, p < .001; plasma CBD [ng/mL]: M_men = 1.14, M_women = 0.53, p = .04). Despite this, sex differences in subjective effects and verbal memory errors did not emerge, although women reported a steeper decrease in drug liking after use (p = .04).

CONCLUSION

These data provide the first look at sex differences after acute naturalistic cannabis concentrate use, and suggest much higher THC exposure in men versus women, but similar acute drug and impairment effects across the sexes. Further studies are needed to determine the mechanisms (e.g. tolerance, cannabinoid metabolism, smoking topography) behind these findings.

Cannabidiol enhanced the development of sensitization to the expression of methamphetamine-induced conditioned place preference in male rats

Cannabis and ecstasy are illicit substances, and currently, there are no approved treatments for methamphetamine (METH) use disorder. Some studies have proposed that cannabidiol (CBD) decreases the motivation for METH seeking, but reports indicate that the therapeutic benefits are only for heroin. Here, we studied the interaction between CBD and METH during the sensitization phase on the rewarding effect of METH, using the conditioned place preference (CPP) paradigm to measure possible alterations in sensitivity. Our data showed that i. p. injection of METH created METH-induced CPP at two of the highest applied doses (1 and 2 mg/kg), and injection of METH during the sensitization period caused an establishment of METH-induced CPP at lower doses (0.25 and 0.5 mg/kg). Data also revealed that i. c.v. administration of CBD during the sensitization phase, shifted the establishment of METH-induced CPP toward a lower dose (0.5 mg/kg). Concurrent administration of CBD (10 μg/5 μl, i. c.v.) and METH (0.25 mg/kg, i. p.) during sensitization phase established METH-induced CPP with sub-threshold doses of METH (0.125, 0.25, and 0.5 mg/kg). Our results suggest the involvement of CBD and prior exposure to METH in creating sensitization to METH CPP.

CANreduce 2.0 Adherence-Focused Guidance for Internet Self-Help Among Cannabis Users: Three-Arm Randomized Controlled Trial

Background

Despite increasing demand for treatment among cannabis users in many countries, most users are not in treatment. Internet-based self-help offers an alternative for those hesitant to seek face-to-face therapy, though low effectiveness and adherence issues often arise.

Objective

Through adherence-focused guidance enhancement, we aimed to increase adherence to and the effectiveness of internet-based self-help among cannabis users.

Methods

From July 2016 to May 2019, cannabis users (n=775; male: 406/575, 70.6%, female: 169/575, 29.4%; age: mean 28.3 years) not in treatment were recruited from the general population and were randomly assigned to (1) an adherence-focused guidance enhancement internet-based self-help intervention with social presence, (2) a similar intervention with an impersonal service team, and (3) access to internet as usual. Controls who were placed on a waiting list for the full intervention after 3 months underwent an assessment and had access to internet as usual. The primary outcome measurement was cannabis-use days over the preceding 30 days. Secondary outcomes included cannabis-dependence severity, changes in common mental disorder symptoms, and intervention adherence. Differences between the study arms in primary and secondary continuous outcome variables at baseline, posttreatment, and follow-up were tested using pooled linear models.

Results

All groups exhibited reduced cannabis-use days after 3 months (social presence: –8.2 days; service team: –9.8 days; internet as usual: –4.2 days). The participants in the service team group (P=.01, d=.60) reported significantly fewer cannabis-use days than those in the internet as usual group; the reduction of cannabis use in the social presence group was not significant (P=.07, d=.40). There was no significant difference between the 2 intervention groups regarding cannabis-use reduction. The service team group also exhibited superior improvements in cannabis-use disorder, cannabis-dependence severity, and general anxiety symptoms after 3 months to those in the internet as usual group.

Conclusions

The adherence-focused guidance enhancement internet-based self-help intervention with an impersonal service team significantly reduced cannabis use, cannabis-use disorder, dependence severity, and general anxiety symptoms.

Trial Registration

ISRCTN Registry ISRCTN11086185; http://www.isrctn.com/ISRCTN11086185

Sleep deficits and cannabis use behaviors: an analysis of shared genetics using linkage disequilibrium score regression and polygenic risk prediction

STUDY OBJECTIVES

Estimate the genetic relationship of cannabis use with sleep deficits and an eveningness chronotype.

METHODS

We used linkage disequilibrium score regression (LDSC) to analyze genetic correlations between sleep deficits and cannabis use behaviors. Secondly, we generated sleep deficit polygenic risk score (PRS) and estimated their ability to predict cannabis use behaviors using linear and logistic regression. Summary statistics came from existing genome-wide association studies of European ancestry that were focused on sleep duration, insomnia, chronotype, lifetime cannabis use, and cannabis use disorder (CUD). A target sample for PRS prediction consisted of high-risk participants and participants from twin/family community-based studies (European ancestry; n = 760, male = 64%; mean age = 26.78 years). Target data consisted of self-reported sleep (sleep duration, feeling tired, and taking naps) and cannabis use behaviors (lifetime ever use, number of lifetime uses, past 180-day use, age of first use, and lifetime CUD symptoms).

RESULTS

Significant genetic correlation between lifetime cannabis use and an eveningness chronotype (rG = 0.24, p < 0.001), as well as between CUD and both short sleep duration (<7 h; rG = 0.23, p = 0.017) and insomnia (rG = 0.20, p = 0.020). Insomnia PRS predicted earlier age of first cannabis use (OR = 0.92, p = 0.036) and increased lifetime CUD symptom count (OR = 1.09, p = 0.012).

CONCLUSION

Cannabis use is genetically associated with both sleep deficits and an eveningness chronotype, suggesting that there are genes that predispose individuals to both cannabis use and sleep deficits.

Satisfaction With Life, Mental Health Problems and Potential Alcohol-Related Problems Among Norwegian University Students

Objective: Recent studies have shown that today's college students more than ever are struggling with mental health and alcohol problems. While poor satisfaction with life and mental health problems have been linked to higher alcohol consumption, there is still a lack of studies examining in detail the shape and nature of the relationship between mental health and alcohol consumption. Aim: To investigate the associations between satisfaction with life, mental health problems and potential alcohol-related problems among Norwegian university students. The shape of the associations was also examined. Methods: Data were drawn from a 2018 national survey of students in higher education in Norway (the SHoT-study). Associations between satisfaction with life, mental health problems and potential alcohol-related problems (AUDIT; risky and harmful alcohol use) were investigated using logistic regression. Both crude models and models adjusted for age, gender and marital status were conducted. To investigate the shape of the associations, logistic regression with quadric and cubic terms was tested. Results: Decreased satisfaction with life and increased mental health problems were associated with potential alcohol-related problems. For satisfaction with life, a curvilinear association with risky alcohol use and a linear association with harmful alcohol use was identified. For mental health problems, curvilinear associations were found for both risky and harmful alcohol use. Conclusion: Many students report potential alcohol-related problems. Students with harmful alcohol use seem to be more at risk of reduced satisfaction with life and increased mental health problems than students with risky alcohol use. Educational institutions may be an ideal setting for raising awareness of mental health issues and responsible alcohol consumption among students. The present study contributes with important information about the shape of the associations between satisfaction with life, mental health problems and potential alcohol-related problems in the student population.

Relations between cannabis use, socioeconomic status, and risk perceptions in a Hispanic/Latinx population

Socioeconomic status (SES) and risk perceptions are indicative of cannabis use and subjective social status (SSS) may have utility in predicting cannabis use. This work examined relations between these indicators of cannabis use and use in a Hispanic/Latinx sample. Results found negative relations between risk perceptions and cannabis use. SES was unrelated to cannabis outcomes and risk perceptions but SSS had a negative relation with lifetime use. SSS positively related to risk assimilation in the full sample. Findings demonstrate how risk perceptions relate to cannabis use and suggest SES and SSS may not be indicative of use among Hispanic/Latinx populations.

Risk taking, sensation seeking and personality as related to changes in substance use from adolescence to young adulthood

INTRODUCTION

This study examined changes in substance use from adolescence to young adulthood as related to adolescents' risk taking, sensation seeking, antisocial activities, and personality traits.

METHODS

Chilean youth (N = 890, 52% female) were studied in adolescence (14.5 and 16.2 years) and young adulthood (M age 21.3 years). Risk taking was assessed via a laboratory-based performance task (Balloon Analogue Risk Task), and self-administered questionnaires assessed sensation seeking, antisocial behaviors, personality and substance use.

RESULTS

Frequent involvement in sensation seeking and antisocial activities were associated with increased odds of continued marijuana use from adolescence to young adulthood and of illicit substance use at young adulthood. High risk taking was associated with a reduced likelihood of discontinuing marijuana use at young adulthood, and high agreeableness and conscientiousness were associated with reduced likelihood of new onset marijuana use and illicit substance use at young adulthood.

CONCLUSIONS

Results highlight specific risk-taking tendencies and personality characteristics that relate to initiating, continuing, or discontinuing substance use at entry into adulthood. Sensation seeking and involvement in antisocial activities were the two foremost risk factors for continued use, which is a forecaster of drug dependence. Findings suggest potential prevention and intervention targets for abstaining from or discontinuing substance use as youth transition to adulthood.

Psychosocial functioning among college students who misuse stimulants versus other drugs

The misuse of prescription stimulants (e.g., Ritalin, Adderall) is a large and growing problem on college campuses. Emerging research examines not only the demographic predictors of stimulant misuse but also the potentially role that stimulant misuse plays in a college student's overall functioning and mental health. To better understand the experiences specifically linked with stimulant misuse rather than substance use more broadly, we tested whether psychosocial functioning differed across four groups of college students: those who do not misuse stimulants or other hard drugs; those who misuse both stimulants and other hard drugs; those who misuse stimulants but not other hard drugs; and those who misuse other hard drugs but not stimulants (N = 1534; 40.3% male; 33.9% ethnic minority). Those who misused stimulants reported higher levels of impulsivity, as well as substance use consequences, than those who did not use any hard drugs. However, these differences were exacerbated among those who misused stimulants and other hard drugs. Taken together, these findings suggest that stimulant misuse typically occurs in a broader pattern of substance use, and that stimulant misusers generally fall along a continuum of substance use severity in terms of psychosocial functioning.

Marijuana in pediatric and adult congenital heart disease heart transplant listing: A survey of provider practices and attitudes

Despite increasing legalization and use of marijuana, there is no consensus among pediatric heart transplant institutions or providers regarding users' eligibility for cardiac transplant. We sent a survey to pediatric and ACHD transplant providers (physicians, surgeons, transplant coordinators, and pharmacists) assessing their current institution's policies and their personal opinions about marijuana use in patients being considered for heart transplantation. Of the respondents, 84% practice in the United States and Canada. Most providers (80%) care for both pediatric and ACHD patients. Respondents included cardiologists (77%) and surgeons (11%), with the remaining being coordinators and pharmacists. Most providers (73%) reported their institution had no policy regarding marijuana use in heart transplant candidates. Only 20% of respondents' institutions consider mode of consumption, with 87% and 53% approving of oral and transdermal routes, respectively, and only 7% approving of vaporized or smoked routes. While 73% of providers would consider illegal marijuana use an absolute/relative contraindication to heart transplant listing, the number decreases to 57% for legal recreational users and 21% for legal medical users. Most providers personally believe marijuana to be physically and mentally/emotionally harmful to pediatric patients (67% and 72%, respectively). Many institutions lack a policy regarding marijuana use in pediatric and ACHD heart transplant candidates, and there is considerable disagreement among providers on the best practice. With increasing legalization and use of marijuana, each institution will have to address this issue thoughtfully to continue to provide high-quality, consistent, and equitable care for pediatric and ACHD heart transplant candidates.

Guided web-based treatment program for reducing cannabis use: a randomized controlled trial

Background

The aim of this study was to investigate the effects of a web-based treatment program with therapist guidance for adults and adolescents with regular cannabis use from the general population.

Methods

A double blinded randomized controlled trial with a parallel group design was conducted (intervention group n = 151, wait-list control group n = 152). Follow-up 12 weeks from treatment commencement of a 13-module intervention. The primary outcome was frequency of cannabis use. Time by group interaction effects were modeled using generalized estimated equations and the instrumental variable approach was used to estimate the effect of intervention adherence.

Results

At follow-up, the intention to treat (ITT) analyses did not show any significant time by group effects. A significant association between intervention adherence and scores on the cannabis abuse screening test (CAST) was found. Secondary analysis excluding participants who had received other professional help revealed time by group effects for secondary outcomes gram cannabis consumed past week, number of dependency criteria and CAST score. Due to methodological limitations, these latter results should be interpreted with caution.

Conclusions

In this study we did not find a web-based treatment program with therapist guidance to be more effective than a waiting-list in reducing frequency of cannabis use.

Trial registration The trial was pre-registered at ClinicalTrials.gov (NCT02408640) April 3, 2015

Interaction of Cannabis Use and Aging: From Molecule to Mind

Given the aging Baby Boomer generation, changes in cannabis legislation, and the growing acknowledgment of cannabis for its therapeutic potential, it is predicted that cannabis use in the older population will escalate. It is, therefore, important to determine the interaction between the effects of cannabis and aging. The aim of this report is to describe the link between cannabis use and the aging brain. Our review of the literature found few and inconsistent empirical studies that directly address the impact of cannabis use on the aging brain. However, research focused on long-term cannabis use points toward cumulative effects on multimodal systems in the brain that are similarly affected during aging. Specifically, the effects of cannabis and aging converge on overlapping networks in the endocannabinoid, opioid, and dopamine systems that may affect functional decline particularly in the hippocampus and prefrontal cortex, which are critical areas for memory and executive functioning. To conclude, despite the limited current knowledge on the potential interactive effects between cannabis and aging, evidence from the literature suggests that cannabis and aging effects are concurrently present across several neurotransmitter systems. There is a great need for future research to directly test the interactions between cannabis and aging.

Drug Abuse and Behavioral Transgressions during Methadone Maintenance Treatment (MMT) are Related to High Psychopathy Levels

Introduction: Studies which used the Psychopathy Checklist-Revised (PCL-R) among methadone maintenance treatment (MMT) patients focused mostly on methodological issues, without addressing its relationship to patients' misconduct during treatment. This paper tests the hypothesis that high PCL-R scores are related to high rates of drug abuse, and high numbers of behavioral transgressions in MMT during a 7-year period. Material and Methods: 107 MMT patients were recruited from a MMT clinic in Israel, and were administered the PCL-R. The questionnaires results as well as routine drug test findings were recorded between 7/2007 and 11/2007. Seven years later (7/2014), repeated drug test results were analyzed, and the number of behavioral transgressions during the entire period was computed. Results: High levels of psychopathy were related to drug test results indicating any illicit drug use, cocaine use and benzodiazepines misuse at the beginning of study, and limited to benzodiazepines misuse among patients who stayed in treatment at the 7-year follow-up. However, higher scores on different PCL-R facets were significantly associated with different types of drugs. The PCL-R's total score and all but the antisociality facet were positively correlated with a higher number of behavioral transgressions (such as, threats and/or verbal and physical aggression). Conclusions: Administration of the PCL-R during MMT may help identify patients with high illicit drug use levels and a higher chance of committing behavioral transgressions during treatment.

Cannabis use during methadone maintenance treatment for opioid use disorder: a systematic review and meta-analysis

BACKGROUND

Rates of cannabis use among patients receiving methadone maintenance therapy are high, and cannabis use may be associated with outcomes of methadone maintenance therapy. We examined the effect of cannabis use on opioid use in patients receiving methadone maintenance therapy to test the hypothesis that cannabis use is associated with a reduction in opioid use.

METHODS

In this systematic review, we searched MEDLINE/PubMed, Embase, PsycINFO, CINAHL and ProQuest Dissertations and Theses Global from inception to July 12, 2018. We summarized the effects of cannabis use on opioid use during methadone maintenance therapy and treatment retention. We conducted meta-analyses using a random effects model.

RESULTS

We included 23 studies in our review. We performed a meta-analysis of 6 studies, with a total number of participants of 3676, examining use of cannabis and opioids during methadone maintenance therapy. Owing to high heterogeneity, we described the studies qualitatively but provide the forest plots as supplemental material. The overall quality of evidence was very low, with a high risk of bias, owing to the nature of observational studies.

INTERPRETATION

We found no consensus among studies that cannabis use is associated with reduced opioid use or longer treatment retention when used during methadone maintenance therapy in patients with opioid use disorder. PROSPERO Registration: CRD42015029372.

The Effects of Marijuana Use on Transitions through Stages of Alcohol Involvement for Men and Women in the NESARC I and II

Background: With the changing context of marijuana use, it is critical to identify effects of use. We extend previous work by examining whether marijuana use influences progression and remission through alcohol involvement stages for men and women. Methods: Data come from Waves I and II of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC, n = 34,432). We assess the potential influence of marijuana use at Wave 1 on transitions across three latent statuses of alcohol involvement between waves. We apply propensity score weighting to account for shared risk factors. Results: Marijuana use was associated cross-sectionally and longitudinally with alcohol involvement statuses for both sexes. After propensity score adjustment, men with marijuana histories were 3.50 times as likely as men without such histories to transition from no to severe problems across waves relative to staying in the same status (p < .001). Women with marijuana histories were 1.74 times as likely as women without such histories to transition from no problems at Wave 1 to moderate problems at Wave 2 (p = .030) and 0.13 times as likely as women without such histories to transition from severe problems to no problems (p = .006). Conclusions: Results suggest that marijuana use impacts progression to more serious stages of alcohol involvement for both men and women, as well as hinders remission among women. Findings point to the importance of screening those with marijuana histories for alcohol problems, as well as the need to understand the mechanism of why marijuana use may increase the risk of alcohol problems.

Is Cannabis Use Associated With Increased Risk of Cigarette Smoking Initiation, Persistence, and Relapse? Longitudinal Data From a Representative Sample of US Adults

OBJECTIVE

The current study prospectively investigated the relationship between cannabis use and cigarette smoking initiation, persistence, and relapse during a 3-year period among adults in the United States.

METHODS

Analyses included respondents who completed Waves 1 (2001-2002) and 2 (2004-2005) of the National Epidemiologic Survey on Alcohol and Related Conditions and responded to questions about cannabis use and smoking status (n = 34,639). Multivariable logistic regression models were used to calculate the odds of cigarette use at Wave 2 among Wave 1 daily smokers, nondaily smokers, former smokers, and nonsmokers by Wave 1 cannabis use.

RESULTS

In unadjusted analyses, Wave 1 cannabis use was associated with increased odds of Wave 2 daily and nondaily smoking for Wave 1 nonsmokers (daily OR = 2.90; 95% CI, 2.10-4.00; nondaily OR = 4.45; 95% CI, 3.97-5.00) and Wave 2 relapse to daily and nondaily smoking for Wave 1 former smokers (daily OR = 4.18, 95% CI, 3.01-5.81; nondaily OR = 5.24; 95% CI, 3.74-7.34). Wave 1 cannabis use was associated with decreased odds of Wave 2 smoking cessation for Wave 1 daily cigarette smokers (OR = 0.57; 95% CI, 0.51-0.64). The associations remained significant for daily smoking initiation (OR = 1.43; 95% CI, 1.06-1.93), daily smoking relapse (OR = 1.47; 95% CI, 1.00-2.16), and smoking cessation (OR = 0.77; 95% CI, 0.69-0.87) after adjusting for demographics and psychiatric disorders. Associations remained significant for nondaily smoking initiation (OR = 1.85; 95% CI, 1.59-2.16) and nondaily smoking relapse (OR = 1.63; 95% CI, 1.05-2.54) after adjusting for these covariates as well as for alcohol and substance use disorders.

CONCLUSIONS

Cannabis use was associated with increased initiation of, persistence of, and relapse to cigarette smoking. Additional attention to cannabis use in tobacco control efforts and in clinical settings aimed at reducing cigarette smoking and smoking-related negative consequences may be warranted.

Single and dual diagnoses of major depressive disorder and posttraumatic stress disorder predicted by triple comorbid trajectories of tobacco, alcohol, and marijuana use among urban adults

Background: The adverse consequences of major depressive disorder (MDD) and posttraumatic stress disorder (PTSD) affect a significant portion of the US population every year (i.e., 15 million for MDD; 8 million for PTSD) and are of public health concern. The current study examines tobacco, alcohol, and marijuana use as possible longitudinal predictors of MDD and/or PTSD. Methods: A community sample of 674 participants (53% African Americans and 47% Puerto Ricans; 405 females and 269 males) were recruited from the Harlem Longitudinal Development Study. We used Mplus software to obtain the triple trajectories of tobacco, alcohol, and marijuana use from mean age 14 to 36. Logistic regression analyses were then conducted to examine the associations between those triple trajectory groups and a single diagnosis of MDD or PTSD as well as a dual diagnosis of MDD with PTSD at age 36. Results: The observed percentages of MDD, PTSD, and the comorbidity of MDD and PTSD were 17%, 8%, and 5%, respectively. The heavy use of all 3 substances group was associated with an increased likelihood of having MDD (adjusted odds ratio [AOR] = 3.14, P < .01), PTSD (AOR = 3.91, P < .05), and MDD with PTSD (AOR = 6.64, P < .01), as compared with the tobacco and alcohol use group. Conclusions: Treatment programs to quit or reduce the use of tobacco, alcohol, and marijuana may help decrease the prevalence of MDD and PTSD. This could lead to improvements in individualized treatments for patients who use tobacco, alcohol, and marijuana and who have both MDD and PTSD.

Triple comorbid trajectories of alcohol, cigarette, and marijuana use from adolescence to adulthood predict insomnia in adulthood

Approximately 9% of adults report the symptoms of insomnia, and there are a number of adverse consequences of insomnia. This could be a public health concern. The current study seeks plausible longitudinal predictors of insomnia for prevention purposes. A community sample of 674 participants (53% African Americans and 47% Puerto Ricans; 60% were females) were recruited from the Harlem Longitudinal Development Study. We applied a growth mixture model to obtain the triple trajectories of alcohol, cigarette, and marijuana use. Logistic regression analyses were then conducted to examine the associations between the triple trajectory groups from mean age 14 to 36 and insomnia at age 36. The estimated prevalence of insomnia is 7.1%. A five-group triple trajectory model was selected: A) Increasing use of all three substances (18%); B) Moderate use of alcohol and marijuana, and high use of cigarette (11%); C) Moderate use of alcohol and cigarette, and experimental use of marijuana (3%); D) Moderate use of all three substances (5%); and E) No or low use of all three substances (63%). Among the five trajectory groups, the increasing use of all three substances group (AOR = 2.71, p-value = .011) was associated with an increased likelihood of having insomnia as compared to the no or low use of all three substances group. Treatment programs to quit or reduce the use of alcohol, cigarette, and marijuana may help decrease the prevalence of insomnia. This could lead to improvements in individualized treatments for patients who have symptoms of insomnia and who also use substances.

An Examination of the Importance of Strain in the Cannabis Gateway Effect

Gateway theory has been the source of much debate in both the research literature and public policy. Support for gateway sequencing has been mixed, especially in research that has considered the role of criminological variables in the etiology of substance use. For example, limited prior research has observed as important in gateway sequencing the effects of severe stressors. Data from the National Longitudinal Study of Adolescent to Adult Health are utilized to test gateway theory and examine whether severe stressors affect the relationship between frequency of cannabis use and later use of other illicit drugs (OIDs). Findings suggest that while frequency of cannabis use does increase the likelihood of later use of OIDs, this relationship may be the result of the common cause of experiencing severe stress. Implications of the findings are discussed.

Nicotine dependence predicts cannabis use disorder symptoms among adolescents and young adults

PURPOSE

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.

METHODS

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).

RESULTS

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.

CONCLUSION

Prevention and treatment efforts should consider cigarette smoking comorbidity when addressing the increasing proportion of the US population that uses cannabis.

The Effects of Social Presence on Adherence-Focused Guidance in Problematic Cannabis Users: Protocol for the CANreduce 2.0 Randomized Controlled Trial

Background

In European countries, including Switzerland, cannabis is the most commonly used illicit drug. Offering a Web-based self-help tool could potentially reach users who otherwise would not seek traditional help. However, such Web-based self-help tools often suffer from low adherence.

Objective

Through adherence-focused guidance enhancements, the aim of this study was to increase adherence in cannabis users entering a Web-based self-help tool to reduce their cannabis use and, in this way, augment its effectiveness.

Methods

This paper presents the protocol for a three-arm randomized controlled trial (RCT) to compare the effectiveness of (1) an adherence-focused, guidance-enhanced, Web-based self-help intervention with social presence; (2) an adherence-focused, guidance-enhanced, Web-based self-help intervention without social presence; and (3) a treatment-as-usual at reducing cannabis use in problematic users. The two active interventions, each spanning 6 weeks, consist of modules designed to reduce cannabis use and attenuate common mental disorder (CMD) symptoms, including depression, anxiety, and stress-related disorder symptoms based on the approaches of motivational interviewing and cognitive behavioral therapy. With a target sample size of 528, data will be collected at baseline, 6 weeks, and 3 months after baseline. The primary outcome measurement will be the number of days of cannabis use on the preceding 7 days. Secondary outcomes will include the quantity of cannabis used in standardized cannabis joints, the severity of cannabis dependence, changes in CMD symptoms, and adherence to the program. Data analysis will follow the intention-to-treat principle and employ (generalized) linear mixed models.

Results

The project commenced in August 2016; recruitment is anticipated to end by December 2018. First results are expected to be submitted for publication in summer 2019.

Conclusions

This study will provide detailed insights on if and how the effectiveness of a Web-based self-help intervention aiming to reduce cannabis use in frequent cannabis users can be improved by theory-driven, adherence-focused guidance enhancement.

Trial Registration

International Standard Randomized Controlled Trial Number Registry: ISRCTN11086185; http://www.isrctn.com/ISRCTN11086185 (Archived by WebCite at http://www.webcitation.org/6wspbuQ1M)

The impact of cannabis use on patients enrolled in opioid agonist therapy in Ontario, Canada

Background

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.

Methods

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.

Results

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.

Interpretation

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.

DSM-5 cannabis use disorder, substance use and DSM-5 specific substance-use disorders: Evaluating comorbidity in a population-based sample

Cannabis use disorder (CUD) is frequently associated with concurrent substance use and/or comorbid substance use disorders (SUDs); however there is little specificity with regard to commonly abused individual drug types/classes. This study therefore aimed to provide insight into the degree of these co-occurring relationships across several specific newer and older generation illicit and prescription drugs. 36,309 adults aged 18+ from wave 3 of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC-III) were assessed. Weighted cross-tabulations and multivariable logistic regression analyses were used to evaluate comorbidity between current DSM-5 CUD, substance use and DSM-5 SUD. Current DSM-5 CUD is associated with greater lifetime use of all examined drug classes, and previous 12-month use of several newer-class illicit and prescription stimulant-based substances (all p< 0.05). Current DSM-5 CUD was similarly associated with increased incidence of a range of DSM-5 SUDs and was independently associated with concurrently reporting current DSM-5; sedative (Adjusted OR= 5.1, 95%CI 2.9-9.0), cocaine (AOR= 9.3, 95%CI 5.6-15.5), stimulant (AOR= 4.3, 95%CI 2.3-7.9), club drug (AOR= 16.1, 95%CI 6.3-40.8), opioid (AOR= 4.6, 95%CI 3.0-6.8) and alcohol-use disorder (AOR= 3.0, 95%CI 2.5-3.7); but not heroin or 'other' drug use disorder (both p>0.05). High comorbidity exists between DSM-5 CUD and many specific DSM-5 SUDs. Newer-class illicit and prescription stimulant-based drug use disorders are overrepresented among those with DSM-5 CUD. These findings underscore the need for tailored treatment programs for those presenting with DSM-5 CUD, and for greater treatment specification where poly-drug use is evident.

Adolescent Exposure to the Synthetic Cannabinoid WIN 55212-2 Modifies Cocaine Withdrawal Symptoms in Adult Mice

Chronic cannabinoid consumption is an increasingly common behavior among teenagers and has been shown to cause long-lasting neurobehavioral alterations. Besides, it has been demonstrated that cocaine addiction in adulthood is highly correlated with cannabis abuse during adolescence. Cocaine consumption and subsequent abstinence from it can cause psychiatric symptoms, such as psychosis, cognitive impairment, anxiety, and depression. The aim of the present research was to study the consequences of adolescent exposure to cannabis on the psychiatric-like effects promoted by cocaine withdrawal in adult mice. We pre-treated juvenile mice with the cannabinoid CB1 receptor agonist WIN 55212-2 (WIN) and then subjected them to a chronic cocaine treatment during adulthood. Following these treatments, animals were tested under cocaine withdrawal in the following paradigms: pre-pulse inhibition, object recognition, elevated plus maze, and tail suspension. The long-term psychotic-like actions induced by WIN were not modified after cocaine cessation. Moreover, the memory impairments induced by cocaine withdrawal were not altered by previous adolescent WIN intake. However, WIN pre-treatment prevented the anxiogenic effects observed after cocaine abstinence, and led to greater depressive-like symptoms following cocaine removal in adulthood. This study is the first to show the long-lasting behavioral consequences of juvenile exposure to WIN on cocaine withdrawal in adult mice.

Longitudinal Studies on the Etiology of Cannabis Use Disorder: A Review

PURPOSE OF REVIEW

This review summarizes the literature to date that has capitalized on the longitudinal research study framework in order to elucidate the etiology of cannabis use disorders (CUDs).

RECENT FINDINGS

The studies are mixed with respect to reliable predictors of CUD development. Of the studies outlined, the most consistently indicated risk factors for CUD development include: male sex, past cannabis and other substance use (especially tobacco), and the presence of pre/comorbid psychopathology (especially mood disorders). Social motives and peer involvement may also play a role in this transition. Many of these CUD risk factors appear to be distinct from other factors linked with overall cannabis use.

SUMMARY

CUD development is likely the product of interactions between biological, psychological, social, and environmental factors. However, many more well-planned and developmentally sensitive prospective studies are needed to identify specific and reliable risk factors for CUD development.

Marijuana use disorder symptoms among recent onset marijuana users

BACKGROUND

With recreational marijuana having recently been legalized in a growing number of U.S. states, as well as the increasing support for its legalization among substantial segments of the American public, an understanding of the development of symptoms associated with marijuana use disorders will assist in guiding both education and policy.

METHODS

This study examined the prevalence of marijuana use disorder symptoms among a nationally representative sample of recent onset marijuana users ages 12-21 drawn from the National Survey of Drug Use and Health (N=9697).

RESULTS

The most frequently reported marijuana use symptoms were "tolerance", and "time occupied acquiring, using or recovering from the effects of marijuana". Logistic regression analyses indicated an expected positive association between marijuana use frequency and each marijuana use disorder symptom. In many cases the positive trend was quadratic or cubic, with greater increases between rates among low and moderate frequency marijuana users (i.e. 1-10days per month) than among those using at a higher frequency (i.e. >10days per month). Relationships between marijuana use frequency and marijuana use symptoms were largely consistent according to age, gender and ethnicity.

CONCLUSIONS

Recognizing symptoms of marijuana use disorders among adolescents and young adults using marijuana infrequently may assist in early identification and intervention for those at risk for problem use.

Cannabis use during treatment for alcohol use disorders predicts alcohol treatment outcomes

AIMS

To compare post-treatment alcohol use between those who use cannabis and those who abstain during treatment for alcohol use disorders (AUD); and to examine potential cannabis use thresholds by comparing post-treatment alcohol use between four frequency groups of cannabis users relative to abstainers.

DESIGN

Secondary analyses of the Combined Pharmacotherapies and Behavioral Interventions (COMBINE) Study, a randomized control trial of AUD treatments. The current study compares longitudinal drinking data between those who used cannabis versus those who abstained during COMBINE treatment.

SETTING

The COMBINE Study treatments were delivered on an out-patient basis for 16 weeks. The current analyses include 206 cannabis users and 999 cannabis abstainers.

PARTICIPANTS

All participants met diagnosis of primary alcohol dependence (n = 1383).

MEASUREMENTS

Primary exposures were any cannabis use and quartiles of cannabis use (Q1: 1-4 use days during treatment, Q2: 5-9 days, Q3: 10-44 days, Q4: 45-112 days). Outcomes were percentage of days abstinent from alcohol (PDA), drinks per drinking day (DPDD) and percentage of heavy drinking days (PHD), all measured at treatment end and 1 year post-treatment.

FINDINGS

Compared with no cannabis use, any cannabis use during treatment was associated with 4.35% [95% confidence interval (CI) = -8.68, -0.02], or approximately 4 fewer alcohol abstinent days at the end of treatment. This association weakened by 1 year post-treatment (95% CI = -9.78, 0.54). Compared with no cannabis use, only those in the second quartile of cannabis use (those who used once or twice per month during treatment) had 8.81% (95% CI = -17.00, -0.63), or approximately 10 fewer days alcohol abstinent at end of treatment, and 11.82% (95% CI = -21.56, -2.07), or approximately 13 fewer alcohol abstinent days 1 year post-treatment. Neither any cannabis use nor quartiles were associated with DPDD or PHD at either time-point.

CONCLUSIONS

Among individuals in alcohol treatment, any cannabis use (compared with none) is related to a significantly lower percentage of days abstinent from alcohol post-treatment, although only among those who used cannabis once or twice per month.

Association between cannabis use and methadone maintenance treatment outcomes: an investigation into sex differences

Background

Cannabis will soon become legalized in Canada, and it is currently unclear how this will impact public health. Methadone maintenance treatment (MMT) is the most common pharmacological treatment for opioid use disorder (OUD), and despite its documented effectiveness, a large number of patients respond poorly and experience relapse to illicit opioids. Some studies implicate cannabis use as a risk factor for poor MMT response. Although it is well established that substance-use behaviors differ by sex, few of these studies have considered sex as a potential moderator. The current study aims to investigate sex differences in the association between cannabis use and illicit opioid use in a cohort of MMT patients.

Methods

This multicentre study recruited participants on MMT for OUD from Canadian Addiction Treatment Centre sites in Ontario, Canada. Sex differences in the association between any cannabis use and illicit opioid use were investigated using multivariable logistic regression. A secondary analysis was conducted to investigate the association with heaviness of cannabis use.

Results

The study included 414 men and 363 women with OUD receiving MMT. Cannabis use was significantly associated with illicit opioid use in women only (OR = 1.82, 95% CI 1.18, 2.82, p = 0.007). Heaviness of cannabis use was not associated with illicit opioid use in men or women.

Conclusions

This is the largest study to date examining the association between cannabis use and illicit opioid use. Cannabis use may be a sex-specific predictor of poor response to MMT, such that women are more likely to use illicit opioids if they also use cannabis during treatment. Women may show improved treatment outcomes if cannabis use is addressed during MMT.

Comparison of brief versus extended personalised feedback in an online intervention for cannabis users: Short-term findings of a randomised trial

Previous studies have shown brief online self-help interventions to be a useful method of treating cannabis use and related problems; however, no studies have compared the effects of brief versus extended feedback for online brief intervention programs.

OBJECTIVES

The current study was a two arm randomised trial aimed at testing the short term effectiveness of a brief and extended feedback version of Grassessment, a brief online intervention for cannabis users that provides individualised feedback regarding use, motives, and harms.

METHODS

Participants (n=287) reporting at least one symptom of DSM IV cannabis abuse or dependence were recruited using online and offline advertising methods. Participants were randomised to receive either a brief or extended feedback version of the Grassessment program and were required to complete a one month follow up questionnaire.

RESULTS

One hundred and ninety four participants completed the one month follow up. Wilcoxon analyses showed a significant decrease in past month quantity and frequency of cannabis use (ps<0.001; r=-0.41 and -0.40 respectively) and lower severity of dependence scores (p=0.002; r=-0.31) among those in the brief feedback condition. Participants in the extended feedback group also demonstrated significant decreases in patterns of use (ps<0.002; r=-0.39 and -0.33) but not severity of dependence (p=0.09; r=0.18). A Generalized Estimating Equation (GEE) analysis showed no significant interaction between length of feedback received and past month cannabis use frequency (p=0.78), quantity (p=0.73), or severity of dependence (p=0.47).

CONCLUSION

This study adds support for the use of brief online self-complete interventions to reduce cannabis use and related problems in the short term. The findings suggest that in the case of the brief online screening and feedback program Grassessment, extended feedback does not lead to superior outcomes over brief feedback.

Cannabis Use and Cannabis Use Disorders Among Youth in the United States, 2002-2014

OBJECTIVE

To examine trends in past-year cannabis use (CU) and cannabis use disorders (CUD) among youth in the United States, when related changes began, and factors associated with these changes.

METHODS

This study used data from 288,300 persons aged 12-17 years who participated in the 2002-2014 National Survey on Drug Use and Health. Descriptive analyses and bivariable and multivariable logistic regressions were applied (using the year 2002 as the reference group for most analyses).

RESULTS

The prevalence of past-year CU among youth decreased from 15.8% in 2002 to 13.1% in 2014 (this downward trend occurred during 2002-2007 only [β = -0.0540, P < .0001]). Among youth cannabis users, the prevalence of past-year CUD decreased from 27.0% in 2002 to 20.4% in 2014, with a downward trend starting in 2011 (β = -0.0970, P = .0001). During 2002-2014, the prevalence of past-year tobacco use and alcohol use decreased and prevalences of past-year CU increased among tobacco users and among alcohol users. Our multivariable results suggest that declines in past-year tobacco use (but not alcohol use) among youth were associated with declines in past-year CU during 2010-2014. Past-year CU and CUD were higher among racial/ethnic minorities (except for non-Hispanic Asians and Hawaiians/Pacific Islanders for CU) than non-Hispanic whites and were similar between male and female youth during 2002-2014.

CONCLUSIONS

In the United States, compared to 2002, even after adjusting for covariates, CU decreased among youth during 2005-2014, and CUD declined among youth cannabis users during 2013-2014. Associations between declines in tobacco use and decreased CU suggest the importance of tobacco use control and prevention among youth.

A review of epidemiologic research on smoking behavior among persons with alcohol and illicit substance use disorders

Persons with alcohol use disorders (AUDs) and substance use disorders (SUDs) appear to be heavily affected by cigarette smoking. In order to address the consequences of smoking in this population, an understanding of the current state of knowledge is needed. Epidemiologic research provides the opportunity to obtain detailed information on smoking behaviors in large community samples. The aim of this paper was to synthesize the epidemiologic evidence on smoking among persons with AUDs/SUDs and suggest directions for future research. Literature searches of Medline and PubMed were used to identify articles and additional articles were elicited from publication reference lists. To be included in the review, papers had to be published in English, analyze epidemiologic data, and examine an aspect of smoking behavior in persons with AUDs/SUDs. Twenty-nine studies met inclusion criteria and were included in the review. In summary, epidemiologic evidence to date suggests greater lifetime and current smoking, nicotine dependence, and non-cigarette tobacco use; lower quitting; and differences in quit attempts and withdrawal symptoms for persons with AUDs/SUDs compared to other people. Most studies examined nationally representative data and were conducted on persons in the United States and Australia. Few publications examined outcomes by demographics (e.g., gender, age) but these studies suggested that specific patterns differ by demographic subgroups. More research is needed on persons with AUDs/SUDs in order to develop the most effective public health and clinical interventions to reduce smoking behaviors, improve cessation outcomes, and reduce the harmful consequences of smoking for those with AUDs/SUDs.

Marijuana use from adolescence to adulthood: developmental trajectories and their outcomes

BACKGROUND

The study assesses the degree to which individuals in different trajectories of marijuana use are similar or different in terms of unconventional behavior, sensation seeking, emotional dysregulation, nicotine dependence, alcohol dependence/abuse, children living at home, and spouse/partner marijuana use at age 43.

METHOD

This study used a longitudinal design. The sample participants (N = 548) were first studied at mean age 14 and last studied at mean age 43.

RESULTS

Six trajectories of marijuana use were identified: chronic/heavy users (3.6 %), increasing users (5.1 %), chronic/occasional users (20 %), decreasers (14.3 %), quitters (22.5 %), and nonusers/experimenters (34.5 %). With three exceptions, as compared with being a nonuser/experimenter, a higher probability of belonging to the chronic/heavy, the increasing, or the chronic/occasional user trajectory group was significantly associated with a greater likelihood of unconventional behavior, sensation seeking, emotional dysregulation, nicotine dependence, alcohol dependence/abuse, not having children who lived at home, and having a spouse/partner who used marijuana at early midlife. In addition, compared with being a quitter, a higher probability of belonging to the chronic/heavy user trajectory group was significantly associated with a higher likelihood of unconventional behavior, sensation seeking, emotional dysregulation, alcohol dependence/abuse, and spouse/partner marijuana use. Implications for intervention are presented.

CONCLUSIONS

Trajectories of marijuana use, especially chronic/heavy use, increasing use, and chronic/occasional use, are associated with unconventional behavior, sensation seeking, emotional dysregulation, nicotine dependence, alcohol dependence/abuse, having children who lived at home, and spouse/partner marijuana use at age 43. The importance of the findings for prevention and treatment programs are discussed.

Marijuana use and use disorders in adults in the USA, 2002-14: analysis of annual cross-sectional surveys

BACKGROUND

The study of marijuana use disorders is urgently needed because of increasing marijuana legalisation in multiple jurisdictions, the effect of marijuana use on future risk of psychiatric disorders, and deleterious effects of marijuana exposure. Thus, understanding trends of marijuana use and use disorders and examining factors that might drive these trends (eg, perceptions of harms from marijuana use) is essential.

METHODS

We analysed data from US civilians aged 18 years or older who participated in annual, cross-sectional US National Surveys on Drug Use and Health from 2002 to 2014. The sample in each US state was designed to be approximately equally distributed between participants aged 12-17 years, 18-25 years, and 26 years or older. For each survey year, we estimated prevalence of marijuana use and use disorders, initiation of marijuana use, daily or near daily use, perception of great or no risk of harm from smoking marijuana, perception of state legalisation of medical marijuana use, and mean number of days of marijuana use in the previous year. Descriptive analyses, multivariable logistic regressions, and zero-truncated negative binomial regressions were applied.

FINDINGS

596 500 adults participated in the 2002-14 surveys. Marijuana use increased from 10·4% (95% CI 9·97-10·82) to 13·3% (12·84-13·70) in adults in the USA from 2002 to 2014 (β=0·0252, p<0·0001), and the prevalence of perceiving great risk of harm from smoking marijuana once or twice a week decreased from 50·4% (49·60-51·25) to 33·3% (32·64-33·96; β=-0·0625, p<0·0001). Changes in marijuana use and risk perception generally began in 2006-07. After adjusting for all covariates, changes in risk perceptions were associated with changes in prevalence of marijuana use, as seen in the lower prevalence of marijuana use each year during 2006-14 than in 2002 when perceiving risk of harm from smoking marijuana was included in models. However, marijuana use disorders in adults remained stable at about 1·5% between 2002 and 2014 (β=-0·0042, p=0·22).

INTERPRETATION

Prevalence and frequency of marijuana use increased in adults in the USA starting in approximately 2007 and showing significantly higher results in multivariable models during 2011-14 (compared with 2002). The associations between increases in marijuana use and decreases in perceiving great risk of harm from smoking marijuana suggest the need for education regarding the risk of smoking marijuana and prevention messages.

FUNDING

None.

Cannabis Abuse Is Increasing and Associated with Increased Emergency Department Utilization in Gastroenterology Patients

BACKGROUND

The role of cannabinoids in gastrointestinal diseases is controversial and of great interest, yet their use in patients has not been critically examined.

AIM

To determine the prevalence and effects of cannabis abuse on healthcare utilization, as measured by emergency department (ED) visits, in a large, tertiary gastroenterology practice.

METHODS

All patients seen in the gastroenterology clinic at a tertiary care center during a 27-year period (1986-2013) were included in our study to determine the overall prevalence of cannabis abuse. We matched cannabis abusers 1:2 with non-abusing controls to determine the effect of cannabis on ED utilization, our primary outcome. We used multivariate linear regression to adjust for confounders and define the independent effect of cannabis abuse on ED utilization.

RESULTS

Our prevalence study cohort included 190,303 GI clinic patients with an overall cannabis abuse prevalence of 0.80 % (1520 patients). From 1986 to 2012, the prevalence of cannabis abuse in this clinic increased by 0.73 % (0.03 %/year) (p < 0.0001). From the 1520 cannabis abusers identified, 467 patients were randomly selected as cases and were matched to 934 controls. From this retrospective cohort, the median ED visits/year for cannabis abusers was 1.88 versus 0.89 for non-abusers (p < 0.0001). After multivariate adjustment, cannabis abuse was associated with a 1.47-fold increase (95 % CI 1.23-1.76, p < 0.0001) in median ED visits/year.

CONCLUSIONS

Reported cannabis abuse in GI clinic patients is less prevalent than in the adult US population, but is increasing. Cannabis abuse among gastroenterology patients is associated with increased ED visits.

Trajectories of marijuana use from adolescence to adulthood as predictors of unemployment status in the early forties

OBJECTIVES

To study the degree to which individuals in different trajectories of marijuana use are similar or different in terms of unemployment status at mean age 43.

METHODS

We gathered longitudinal data on a prospective cohort taken from a community sample (N = 548). Forty-nine percent of the original participants were females. Over 90% of the participants were white. The participants were followed from adolescence to early midlife. The mean ages of participants at the follow-up interviews were 14.1, 16.3, 22.3, 27.0, 31.9, 36.6, and 43.0, respectively. We used the growth mixture modeling (GMM) approach to identify the trajectories of marijuana use over a 29-year period.

RESULTS

Five trajectories of marijuana use were identified: chronic users/decreasers (8.3%), quitters (18.6%), increasing users (7.3%), chronic occasional users (25.6%), and nonusers/experimenters (40.2%). Compared with nonusers/experimenters, chronic users/decreasers had a significantly higher likelihood of unemployment at mean age 43 (adjusted odds ratio = 3.51, 95% confidence interval = 1.13-10.91), even after controlling for the covariates.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

The results of the associations between the distinct trajectories of marijuana use and unemployment in early midlife indicate that it is important to develop intervention programs targeting chronic marijuana use as well as unemployment in individuals at this stage of development. Results from this study should encourage clinicians, teachers, and parents to assess and treat chronic marijuana use in adolescents.

Influences of barriers to cessation and reasons for quitting on substance use among treatment-seeking smokers who report heavy drinking

OBJECTIVES

We examined behavioral and cognitively-based quit processes among concurrent alcohol and tobacco users and assessed whether smoking and drinking were differentially influenced.

METHODS

Participants were 200 treatment-seeking smokers (37.50% female; M_age = 30.72; SD = 12.68) who reported smoking an average of 10 or more cigarettes daily for at least one year.

RESULTS

Barriers to cessation (BCS) and reasons for quitting (RFQ) were generally correlated with substance use. BCS moderated the relationship between quit methods and cigarette use such that quit methods were negatively associated with smoking, particularly among those with more BCS. RFQ moderated the association between quit methods and cigarette use such that quit methods were negatively linked with smoking among those with fewer RFQ, but positively linked with smoking among those with more RFQ. Two 3-way interactions emerged. The first 3-way indicated that among individuals with fewer RFQ, quit methods was negatively associated with smoking, and this was strongest among those with more BCS. However, among those with more RFQ, smoking and quit methods were positively associated, particularly among those with more BCS. The second 3-way showed that among those with fewer RFQ, quit methods was negatively linked with drinking frequency, and this was strongest among those with more BCS. However, among those with fewer BCS, drinking and quit methods were positively linked.

CONCLUSIONS

The relationship between behavioral and cognitively-based quit processes and substance use is not straightforward. There may be concurrent substance-using individuals for whom these processes might be associated with increased substance use.

Cannabis Smoking in 2015: A Concern for Lung Health?

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.

Gender differences in the associations among marijuana use, cigarette use, and symptoms of depression during adolescence and young adulthood

INTRODUCTION

As prevalence of marijuana use increases, it is important that we better understand how factors like gender, cigarette use, and depression are related to marijuana use during adolescence and young adulthood. We examined longitudinal relationships among these variables in adolescents moving into young adulthood who were studied longitudinally for six years.

METHODS

1263 individuals were included in the study. Participants were oversampled for ever-smoking a cigarette at baseline, when they were 15-16 years old. Frequency of cigarette smoking and marijuana use, as well as depression symptoms, were assessed at baseline, 6, 15, 24, 60 and 72 months.

RESULTS

Cigarette use frequency and depression symptoms were associated with frequency of marijuana use (p-values<.001), particularly in adolescence, but there were important gender differences in these relationships. Specifically, symptoms of depression were related to marijuana use frequency among males (p<.001), but not females (p=.62). In addition, frequency of marijuana use was associated with increased cigarette use frequency, especially among males who had higher symptoms of depression (p<.001). However, this effect was not seen among females. Exploratory analyses suggested that relationships between frequency of use and depression are specific to marijuana, not cigarettes.

CONCLUSIONS

Marijuana use is strongly related to depression symptoms and cigarette use frequency in males, indicating that in males these detrimental factors converge, whereas in females they do not. Gender differences in the factors related to marijuana use may mean that there are different risks for and consequences from use and have implications for prevention and intervention efforts.

Drugs of abuse and addiction: A slippery slope toward liver injury

Substances of abuse induce alteration in neurobehavioral symptoms, which can lead to simultaneous exacerbation of liver injury. The biochemical changes of liver are significantly observed in the abused group of people using illicit drugs or drugs that are abused. A huge amount of work has been carried out by scientists for validation experiments using animal models to assess hepatotoxicity in cases of drugs of abuse. The risk of hepatotoxicity from these psychostimulants has been determined by different research groups. Hepatotoxicity of these drugs has been recently highlighted and isolated case reports always have been documented in relation to misuse of the drugs. These drugs induce liver toxicity on acute or chronic dose dependent process, which ultimately lead to liver damage, acute fatty infiltration, cholestatic jaundice, liver granulomas, hepatitis, liver cirrhosis etc. Considering the importance of drug-induced hepatotoxicity as a major cause of liver damage, this review emphasizes on various drugs of abuse and addiction which induce hepatotoxicity along with their mechanism of liver damage in clinical aspect as well as in vitro and in vivo approach. However, the mechanisms of drug-induced hepatotoxicity is dependent on reactive metabolite formation via metabolism, modification of covalent bonding between cellular components with drug and its metabolites, reactive oxygen species generation inside and outside of hepatocytes, activation of signal transduction pathways that alter cell death or survival mechanism, and cellular mitochondrial damage, which leads to alteration in ATP generation have been notified here. Moreover, how the cytokines are modulated by these drugs has been mentioned here.

Comorbidity and temporal relations of alcohol and cannabis use disorders from youth through adulthood

BACKGROUND

Alcohol and cannabis are among the most widely used and abused drugs in industrialized societies. Investigations of patterns in comorbidity and temporal sequencing between alcohol use disorders (AUDs) and cannabis use disorders (CUDs) from childhood to adulthood are important for understanding the etiologies of these disorders.

METHODS

The sample comprised 816 individuals (59% male, 89% white). Dichotomous measures indicated whether or not a participant was in an AUD or CUD episode during three developmental periods-youth (childhood through adolescence), early adulthood, and adulthood. Structural equation modeling was used to determine relations between AUDs and CUDs across the three developmental periods, and to test for gender differences.

RESULTS

Concurrent associations between AUD and CUD were significant. Both AUD and CUD in previous developmental periods significantly predicted the same substance disorders in subsequent periods. Cross-lagged paths from youth AUD to young adult CUD and youth CUD to young adult AUD were both significant. However, only the cross-lagged path from youth CUD to adult AUD was significant. The cross-lagged paths from young adult AUD to adult CUD and young adult CUD to adult AUD were both nonsignificant. Males and females were mostly similar with only three differences found between genders.

CONCLUSIONS

Comorbidity of AUDs and CUDs was evident from youth through adulthood but the strength of the relationship lessened in adulthood. Temporal sequencing influences of AUDs and CUDs on each other were similar in youth and adulthood but not young adulthood. Same substance stability was greatest in adulthood.