US Epidemiology of Cannabis Use and Associated Problems

Frequency of cannabis use and alcohol-associated adverse effects in a representative sample of U.S. adolescents and youth (2002-2014) a cross-sectional study

Background

While the link between frequent cannabis use and alcohol use disorders is well documented, it is not clear whether alcohol drinkers who use cannabis less frequently are also vulnerable to alcohol use disorders. We estimate the association of frequency of past 12-months cannabis use with alcohol-associated adverse effects variables in the same time frame: alcohol dependence, heavy drinking, driving under alcohol influence, alcohol-related interpersonal problems, use after interpersonal problems, alcohol-related risky behaviors, and alcohol-related legal problems.

Methods

We analyzed data from U.S. individuals aged 12 to 25 years who participated in annual, cross-sectional U.S. National Surveys on Drug Use and Health from 2002 to 2014. Logistic regression models were used to examine the association of cannabis use with six alcohol-associated adverse effects variables. Frequency of cannabis use served as the primary independent variable, and were divided into four categories: frequent use (21–30 days per month), less frequent use (1–20 days per month), no use over the past 12 months, and no lifetime cannabis use. Alcohol dependence and six alcohol-associated adverse effects variables served as our primary outcomes.

Results

The study included 465,090 respondents aged 12 to 25 years, among all past-year cannabis users, (47.5%) were less frequent (1–20 days/month) users. Less frequent cannabis use was highest among male, 15–25-year-olds, and non-Hispanic white 11.8, 84 and 10.6%, respectively. In adjusted models, past-year less frequent cannabis use (1–20 days/month) was significantly associated with past-year alcohol dependence (adjusted odds ratio aOR 5.57, 95% confidence interval (CI) 5.5–6.4); heavy drinking in the past-year (aOR 3.41, 95% CI 3.2–3.5); alcohol-related interpersonal problems in the past-year (aOR 7.33, 95% CI 7.0–7.5); use after interpersonal problems (aOR 5.17, 95% CI 4.8–5.5); alcohol-related risky behaviors (aOR 7.29, 95% CI 7.0–7.5), and, driving under influence of alcohol (aOR 7.19, 95% CI 6.9–7.4). No cannabis use past-year were more likely to report alcohol dependence (aOR 2.81, 95% CI 2.6–3) compared with no lifetime cannabis use.

Conclusion

These findings indicated that within the general population, not only frequent cannabis user (21–30 days per month) but even less frequent cannabis use (1–20 days/month) was significantly associated with past-year alcohol dependence and alcohol-associated adverse effects than no lifetime cannabis use. These adverse alcohol-related outcomes associated with less frequent cannabis use, should be taken under careful consideration in alcohol use disorder treatment setting and policy planning.

Implications of Medical and Recreational Marijuana Laws for Neuroscience Research: a Review

Purpose of Review

Review of US medical and recreational marijuana laws (MML and RML), their effects on cannabis potency, prevalence of non-medical cannabis use and cannabis use disorder (CUD) in adolescents and adults, and implications for neuroscience research, given what is known about the relationship of cannabis to neurocognitive impairments and underlying brain functioning.

Recent Findings

Cannabis potency may be increasing faster in states with MML or RML than in other states. MML and RML have not impacted prevalence in adolescents but have consistently been shown to increase rates of adult non-medical use and CUD.

Summary

Recent neurocognitive or neuroimaging studies may be more impacted by cannabis than studies conducted when MML and RML were less common. Neurocognitive or neuroimaging studies conducted in MML or RML states should carefully test potential participants for recent cannabis use. More research is needed on cannabis and cognition in medical marijuana patients.

State medical marijuana laws, cannabis use and cannabis use disorder among adults with elevated psychological distress

BACKGROUND

Cannabis use and cannabis use disorder are more prevalent in U.S. states with medical marijuana laws (MMLs), as well as among individuals with elevated psychological distress. We investigated whether adults with moderate and serious psychological distress experienced greater levels of cannabis use and/or disorder in states with MMLs compared to states without MMLs.

METHODS

National Survey of Drug Use and Health data (2013-2017) were used to compare past-month cannabis use, daily cannabis use, and cannabis use disorder prevalence among adults with moderate and serious psychological distress in states with versus without MMLs. We executed pooled multivariable logistic regression analyses to test main effects of distress, MMLs and their interaction, after adjustment.

RESULTS

Compared to states without MMLs, states with MMLs had higher adjusted prevalence of past-month use (11.1 % vs. 6.8 %), daily use (4.0 % vs. 2.2 %), and disorder (1.7 % vs. 1.2 %). Adults with moderate and serious psychological distress had greater adjusted odds of any use (AORs of 1.72 and 2.22, respectively) and of disorder (AORs of 2.17 and 2.94, respectively), compared to those with no/mild distress. We did not find evidence of an interaction between MMLs and distress category for any outcome.

CONCLUSIONS

Associations between elevated distress and cannabis use patterns are no greater in states with MML. However, cannabis use is more prevalent in MML states. Thus, higher base rates of cannabis use and disorder among adults with elevated distress are proportionally magnified in these states.

Obsessive-Compulsive Symptoms and Cannabis Misuse: The Explanatory Role of Cannabis Use Motives

The purpose of the present investigation was to examine the unique explanatory role of cannabis use motives above the effects of each other, for the relationship between obsessive-compulsive symptomatology and different aspects of cannabis misuse among young adults. The transitional years of young adulthood are characterized by new opportunities for experimentation as well as novel external stressors. Collectively, this makes this developmental epoch a sensitive time for manifestations of cannabis misuse. Methods: Bivariate correlations were conducted to examine the association between obsessive-compulsive symptomatology and risky cannabis use, cannabis use problems, and the average quantity of cannabis used per occasion among a young ethno-racially diverse sample of college students with the past year history of cannabis use (N = 177, 68.95% female, Mage = 21.51, SD = 4.24). Next, multiple mediation analyses were conducted to examine the unique explanatory role of cannabis use motives (e.g., enhancement, conformity, coping, social, and expansion) for the association between the obsessive-compulsive symptoms and cannabis misuse variables which showed significant correlation with these symptoms at the bivariate level. Results: Obsessive-compulsive symptoms were significantly correlated with risky cannabis use (r = .19; p = .02), but not cannabis use problems or the average quantity of cannabis used per occasion. Conducting the multiple mediation for the relationship with the significant bivariate correlation, coping motives significantly explained the relationship between obsessive-compulsive symptoms and risky cannabis use (b = 0.04, SE = 0.02, 95% Bootstrapped CI [0.003, 0.10], Completely Standardized Indirect Effects = 0.07), after controlling for the variance accounted for by problematic alcohol use and smoking status. This indirect effect was not significant after adding anxiety and depressive symptoms as covariates to the model. Conclusions: These findings are discussed in terms of the development of specialized treatments to specifically target cannabis use coping motives among individuals with comorbid obsessive-compulsive disorder and cannabis misuse.

What is the prevalence and risk of cannabis use disorders among people who use cannabis? a systematic review and meta-analysis

BACKGROUND AND AIMS

We aim to quantify the prevalence and risk of having a cannabis use disorder (CUD), cannabis abuse (CA) or cannabis dependence (CD) among people in the general population who have used cannabis.

METHOD

We conducted a systematic review of epidemiological cross-sectional and longitudinal studies on the prevalence and risks of CUDs among cannabis users. We identified studies published between 2009 and 2019 through PubMed, the Global Burden Disease (GBD) Database, and supplementary searches up to 2020. The outcomes of interest were CUDs based on DSM or ICD criteria. Estimates were synthesized using random-effects meta-analyses, followed by meta-regression of study characteristics on effect sizes.

RESULTS

From 1383 records identified, 21 studies were included. Meta-analyses showed that among people who used cannabis, 22% (18-26%) have CUD, 13% (8-18%) have CA, and 13% (10-15%) have CD. Estimates from cohort studies, showed that the risk of developing CD increased to 33% (22-44%) among young people who engaged in regular (weekly or daily) use of cannabis. There was a lack of data from cohort studies to estimate the risk of CUD or CA among regular cannabis users.

CONCLUSIONS

Cannabis users need to be informed about the risks of developing CUDs and the higher risks among those who initiate early and use frequently during adolescence. Future studies are needed to examine how changes in cannabis policies may affect the risks of CUDs in the population.

Characterizing psychosis-relevant phenomena and cognitive function in a unique population with isolated, chronic and very heavy cannabis exposure

BACKGROUND

The literature on psychosis-relevant outcomes in cannabis users does not adequately address the confounding effects of other substance use/misuse and psychiatric disorders.

METHODS

We studied a unique population for whom cannabis use is central and necessary to their way of life. They are forbidden from using other substances, including tobacco and alcohol. Their use of cannabis is heavy, chronic, and begins early. The cases were compared with matched controls who did not use cannabis, alcohol, or drugs. The controls were from the same location and shared similar beliefs and lifestyle, except for cannabis use. Attenuated psychosis-relevant phenomena were assessed with the Schizotypal Personality Questionnaire (SPQ) and cognitive functioning with a culture-neutral computerized cognitive battery.

RESULTS

Fifteen cases and 12 matched controls were studied. The cases averaged >30 000 lifetime cannabis exposures. Relative to controls, the cases had significantly higher mean (s.d.) SPQ scores 24 (14.32) v. 13 (8.92), p = 0.031; and poorer cognitive performance, reflected by a lower mean (s.d.) composite cognitive score -0.23 (0.32) v. +0.28 (0.52), p = 0.03. Moderate to large effect sizes were noted for differences in tests of attention, psychomotor speed, working memory, cognitive flexibility, visuo-spatial processing, and verbal memory. A subsample of cases had higher SPQ scores and worse cognitive performance than their siblings not using cannabis.

CONCLUSION

Heavy, chronic, and early cannabis use that is not confounded by other drug use is associated with psychosis-relevant phenomena and cognitive deficits. The findings are relevant to the evolving attitudes and laws about cannabis.

Sperm DNA methylation altered by THC and nicotine: Vulnerability of neurodevelopmental genes with bivalent chromatin

Men consume the most nicotine and cannabis products but impacts on sperm epigenetics are poorly characterized. Evidence suggests that preconception exposure to these drugs alters offspring neurodevelopment. Epigenetics may in part facilitate heritability. We therefore compared effects of exposure to tetrahydrocannabinol (THC) and nicotine on DNA methylation in rat sperm at genes involved in neurodevelopment. Reduced representation bisulfite sequencing data from sperm of rats exposed to THC via oral gavage showed that seven neurodevelopmentally active genes were significantly differentially methylated versus controls. Pyrosequencing data revealed majority overlap in differential methylation in sperm from rats exposed to THC via injection as well as those exposed to nicotine. Neurodevelopmental genes including autism candidates are vulnerable to environmental exposures and common features may mediate this vulnerability. We discovered that autism candidate genes are significantly enriched for bivalent chromatin structure, suggesting this configuration may increase vulnerability of genes in sperm to disrupted methylation.

Urinary Acrylonitrile Metabolite Concentrations Before and after Smoked, Vaporized, and Oral Cannabis in Frequent and Occasional Cannabis Users

Cannabis use through smoking, vaping, or ingestion is increasing, but only limited studies have investigated the resulting exposure to harmful chemicals. N-acetyl-S-(2-cyanoethyl)-L-cysteine (2CYEMA), a urinary metabolite of acrylonitrile, a possible carcinogen, is elevated in the urine of past-30-day cannabis users compared to non-cannabis users. Five frequent and five occasional cannabis users smoked and vaped cannabis on separate days; one also consumed cannabis orally. Urine samples were collected before and up to 72 h post dose and urinary 2CYEMA was quantified. We compared 2CYEMA pre-exposure levels, maximum concentration, time at maximum concentration for occasional versus frequent users following different exposure routes, and measured half-life of elimination. Smoking cannabis joints rapidly (within 10 min) increased 2CYEMA in the urine of occasional cannabis users, but not in frequent users. Urine 2CYEMA did not consistently increase following vaping or ingestion in either study group. Cigarette smokers had high pre-exposure concentrations of 2CYEMA. Following cannabis smoking, the half-lives of 2CYEMA ranged from 2.5 to 9.0 h. 2CYEMA is an effective biomarker of cannabis smoke exposure, including smoke from a single cannabis joint, however, not from vaping or when consumed orally. When using 2CYEMA to evaluate exposure in cannabis users, investigators should collect the details about tobacco smoking, route of consumption, and time since last use as possible covariates.

Examining motivational pathways from adult attention-deficit/hyperactivity disorder symptoms to cannabis use: Results from a prospective study of veterans

Objective: Attention-deficit/hyperactivity disorder (ADHD) is linked prospectively to cannabis; however, no study has examined mechanisms underlying this comorbidity. We examined 5 cannabis motives (i.e., coping with negative affect, sleep, social anxiety, perceived low risk of cannabis, and altered perception) as mediators of the prospective ADHD-cannabis relation. Method: Veterans reporting lifetime cannabis use (N = 361; 93% male; 80% White) completed three semiannual assessments. Prospective mediation models using structural equation modeling analyzed the indirect effects of baseline ADHD symptoms on 12-month cannabis use and problems via each motive at 6 months. Zero-inflated negative binomial models were employed for both manifest outcomes and ADHD symptoms and motives were each modeled as 1-factor latent variables. Results: Sleep motives was a robust mediator for cannabis use frequency in single mediator models and was marginally significant when examined simultaneously with other motives after accounting for baseline cannabis use, demographics, other substance use, and other psychopathology. Coping with negative affect was the only significant mediator of ADHD symptoms and subsequent cannabis problem severity. Conclusion: Among veterans with ADHD symptoms, sleep disturbance is a salient motive for cannabis use, whereas coping with negative affect is a proximal predictor of cannabis problems. Findings support addressing sleep disturbance in adults with ADHD symptoms and converge with extant literature demonstrating robust associations between coping motives and substance use problems. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Cannabis use among US adults with anxiety from 2008 to 2017: The role of state-level cannabis legalization

BACKGROUND

Cannabis use is more common among adults with anxiety. Cannabis legalization is occurring rapidly across the United States (US) and individuals may use cannabis to cope with anxiety. This study investigated whether cannabis use across the US has changed differentially by anxiety status and by state cannabis legalization for medical (MML) and/or recreational use (RML).

METHODS

Public and restricted-use data from the 2004 to 2017 National Survey on Drug Use and Health, an annual cross-sectional, nationally representative survey of US individuals, were analyzed. The prevalence of past-30-day cannabis use by anxiety status in 2017 was estimated among respondents ages ≥18 (n = 42,554) by sociodemographics and state-level cannabis law. Weighted logistic regressions with continuous year as the predictor for the linear time trend were used to examine the time trends in cannabis use by anxiety and cannabis law status from 2004 to 2017 (total combined analytic sample n = 398,967).

RESULTS

Cannabis use was consistently two to three times higher among those with high anxiety compared to those with some or no anxiety and was higher in states with RML compared to MML or no MML/RML. Cannabis use has increased over time among those with and without anxiety overall, in MML states, and in states without MML/RML; with a faster increase in cannabis use among those with high anxiety compared to lower anxiety in states with MML.

CONCLUSIONS

Cannabis use is increasing among American adults overall, yet is disproportionately common among Americans with anxiety especially among those residing in states where cannabis has been legalized.

Cannabis Use in Persons With Inflammatory Bowel Disease and Vulnerability to Substance Misuse

BACKGROUND

It is unknown whether cannabis users self-medicating their inflammatory bowel disease (IBD) symptoms are more likely to have comorbid mental health or personality risk factors associated with an increased potential for substance misuse compared with recreational cannabis users.

METHODS

We surveyed individuals with IBD about their cannabis use, their mental health symptoms, and personality risk factors associated with substance misuse. We compared risk factors for substance misuse between individuals using cannabis to manage IBD symptoms and those using cannabis recreationally.

RESULTS

Of 201 persons with IBD who completed the questionnaire, 108 reported lifetime cannabis use. Of those, a larger proportion of Crohn's disease patients used cannabis to manage IBD symptoms (53% [34/64] vs 28% [12/43]; P = 0.010). Individuals self-medicating with cannabis were more likely to use cannabis for coping reasons (P = 0.016) and demonstrated higher levels of impulsivity (P = 0.004) and depressive symptoms (P = 0.012) when compared with individuals using cannabis recreationally. Logistic regression revealed that cannabis was 4.1 times (P = 0.05) and 3.7 times (P = 0.05) more likely to be used for IBD symptoms by smokers and individuals with moderate-severe depressive symptoms, respectively. Individuals high in impulsivity were 4.1 times more likely to use cannabis for their IBD symptoms than those low in impulsivity (P = 0.005).

CONCLUSIONS

Persons with IBD self-medicating with cannabis have characteristics associated with increased vulnerability to substance misuse when compared with those using cannabis recreationally. Screening for mental health comorbidities and vulnerability to substance misuse should be undertaken if cannabis is to be used to treat IBD symptoms.

Occupational Exposure to Particulate Matter and Volatile Organic Compounds in Two Indoor Cannabis Production Facilities

Legal commercial cultivation and processing of cannabis is a rapidly growing industry in multiple countries. However, to date little effort has been made to characterize and identify the various occupational hazards that workers may be facing in the cannabis production industry, including airborne contaminants that may affect the human respiratory system. In the current study, we quantified occupational exposures to particulate matter (PM) and volatile organic compounds (VOCs) in various task zones of two indoor cannabis facilities in Washington State. Full-shift (8-h) area measurements of PM and VOCs were collected in each task zone. Measurement devices were placed near the employee's work area in order to attempt to estimate the personal exposure to the contaminants. In each task zone we measured particle number concentration, particle mass concentration (PMC), cumulative size distribution of the particles, and total terpene mass concentrations. The mean PMCs were greater in task zones that required the employees to manipulate the cannabis plants and materials. The arithmetic mean PMC for the trim task was 60 µg m-3, preroll task was 45 µg m-3, grow task was 42 µg m-3, and the referent office area was 27 µg m-3. When comparing each task zone PMC to the office referent PMC, the trim task, and the preroll task were significantly higher than the referent group (P-values both <0.05). The arithmetic mean terpene mass concentration for the trim task was 36 mg m-3, preroll task was 9.9 mg m-3, grow task was 15 mg m-3, and for the office referent space was 4.9 mg m-3. Compared with the office space, only the trim task area had significantly elevated terpene mass concentrations (P-value <0.01). We observed a weak but statistically significant correlation between PMC and total terpene mass concentrations (rho = 0.42, P < 0.02). Overall, we observed that exposures to respiratory hazards were highest in task zones where cannabis plants and material were manipulated by workers, including the trim, preroll, and the grow task areas. These observations can help inform the employer of the task zones where exposure to respiratory hazards are the highest, and where it may be beneficial to deploy control measures to reduce worker exposures.

Association of Depression With Past-Month Cannabis Use Among US Adults Aged 20 to 59 Years, 2005 to 2016

IMPORTANCE

Despite studies showing that repeated cannabis use may worsen depressive symptoms, the popular media increasingly presents cannabis as beneficial to mental health, and many members of the public view cannabis as beneficial for depression. Therefore, cannabis use among individuals with depression may be becoming more prevalent.

OBJECTIVE

To examine the association of depression with past-month cannabis use among US adults and the time trends for this association from 2005 to 2016.

DESIGN, SETTING, AND PARTICIPANTS

This repeated cross-sectional study used data from 16 216 adults aged 20 to 59 years who were surveyed by the National Health and Nutrition Examination Survey, a national, annual, cross-sectional survey in the United States, between 2005 and 2016. Data analysis was conducted from January to February 2020.

EXPOSURES

Survey year and depression, as indicated by a score of at least 10 on the Patient Health Questionnaire-9.

MAIN OUTCOMES AND MEASURES

Any past-month cannabis use (ie, ≥1 use in the past 30 days) and daily or near-daily past-month cannabis use (ie, ≥20 uses in the past 30 days). Logistic regression was used to examine time trends in the prevalence of cannabis use, depression, and the association between cannabis use and depression from 2005 to 2016.

RESULTS

The final analysis included 16 216 adults, of whom 7768 (weighted percentage, 48.9%) were men, 6809 (weighted percentage, 66.4%) were non-Hispanic White participants, and 9494 (weighted percentage, 65.6%) had at least some college education. They had a weighted mean age of 39.12 (95% CI, 38.23-39.40) years. Individuals with depression had 1.90 (95% CI, 1.62-2.24) times the odds of any past-month cannabis use and 2.29 (95% CI, 1.80-2.92) times the odds of daily or near-daily cannabis use compared with those without depression. The association between cannabis use and depression increased significantly from 2005 to 2016. The odds ratio for depression and any past-month cannabis use increased from 1.46 (95% CI, 1.07-1.99) in 2005 to 2006 to 2.30 (95% CI, 1.82-2.91) in 2015 to 2016. The odds ratio for depression and daily or near-daily past-month cannabis use increased from 1.37 (95% CI, 0.81-2.32) in 2005 to 2006 to 3.16 (95% CI, 2.23-4.48) in 2015 to 2016.

CONCLUSIONS AND RELEVANCE

The findings of this study indicate that individuals with depression are at increasing risk of cannabis use, with a particularly strong increase in daily or near-daily cannabis use. Clinicians should be aware of these trends and the evidence that cannabis does not treat depression effectively when discussing cannabis use with patients.

Cannabis and acute myocardial infarction

Marijuana is one of the most commonly consumed psychotropic drugs in the world. It has been associated with adverse cardiovascular reactions including acute coronary syndrome, but this information is not widely known among emergency medicine clinicians. This article describes cannabis use as a contributing factor to acute myocardial infarction in a young woman with chest pain.

Association of Recreational Cannabis Laws in Colorado and Washington State With Changes in Traffic Fatalities, 2005-2017

IMPORTANCE

An important consequence of cannabis legalization is the potential increase in the number of cannabis-impaired drivers on roads, which may result in higher rates of traffic-related injuries and fatalities. To date, limited information about the effects of recreational cannabis laws (RCLs) on traffic fatalities is available.

OBJECTIVE

To estimate the extent to which the implementation of RCLs is associated with traffic fatalities in Colorado and Washington State.

DESIGN, SETTING, AND PARTICIPANTS

This ecological study used a synthetic control approach to examine the association between RCLs and changes in traffic fatalities in Colorado and Washington State in the post-RCL period (2014-2017). Traffic fatalities data were obtained from the Fatality Analysis Reporting System from January 1, 2005, to December 31, 2017. Data from Colorado and Washington State were compared with synthetic controls. Data were analyzed from January 1, 2005, to December 31, 2017.

MAIN OUTCOME(S) AND MEASURES

The primary outcome was the rate of traffic fatalities. Sensitivity analyses were performed (1) excluding neighboring states, (2) excluding states without medical cannabis laws (MCLs), and (3) using the enactment date of RCLs to define pre-RCL and post-RCL periods instead of the effective date.

RESULTS

Implementation of RCLs was associated with increases in traffic fatalities in Colorado but not in Washington State. The difference between Colorado and its synthetic control in the post-RCL period was 1.46 deaths per 1 billion vehicle miles traveled (VMT) per year (an estimated equivalent of 75 excess fatalities per year; probability = 0.047). The difference between Washington State and its synthetic control was 0.08 deaths per 1 billion VMT per year (probability = 0.674). Results were robust in most sensitivity analyses. The difference between Colorado and synthetic Colorado was 1.84 fatalities per 1 billion VMT per year (94 excess deaths per year; probability = 0.055) after excluding neighboring states and 2.16 fatalities per 1 billion VMT per year (111 excess deaths per year; probability = 0.063) after excluding states without MCLs. The effect was smaller when using the enactment date (24 excess deaths per year; probability = 0.116).

CONCLUSIONS AND RELEVANCE

This study found evidence of an increase in traffic fatalities after the implementation of RCLs in Colorado but not in Washington State. Differences in how RCLs were implemented (eg, density of recreational cannabis stores), out-of-state cannabis tourism, and local factors may explain the different results. These findings highlight the importance of RCLs as a factor that may increase traffic fatalities and call for the identification of policies and enforcement strategies that can help prevent unintended consequences of cannabis legalization.

Regular cannabis use is associated with blunted affective, but not cardiovascular, stress responses

AIMS

To examine the potential impact of regular cannabis use on cardiovascular and subjective responses to acute stress.

DESIGN

We used a quasi-experimental design in which subjective states and cardiovascular measures were obtained during rest and in response to acute stress challenges in a sample of regular cannabis users and non-users.

PARTICIPANTS

Seventy-nine adults (forty-five cannabis users and thirty-four non-users).

MEASUREMENTS

We measured subjective states (positive affect, state stress, state anxiety, cannabis craving) and cardiovascular indicators (blood pressure, heart rate, mean arterial pressure) during baseline rest and in response to public speaking, mental arithmetic, and cold-pressor challenges. Regular cannabis use was established via self-report and was confirmed with a positive urine drug test.

FINDINGS

Regular cannabis use was associated with blunted positive affect (F = 5.67, p = .002), state stress (F = 6.05, p = .002), and state anxiety (F = 6.48, p < .001) in response to acute stress challenges. There was no evidence of an association between cannabis use and cardiovascular responses (Fs ≤ 1.54; Ps ≥ 0.21). Contrary to expectations, cannabis craving decreased in response to stress challenges (F = 8.44, p < .001).

CONCLUSION

Chronic cannabis use is associated with blunted positive and negative (stress, anxiety) affective responses to acute stress, indicating emotional dysregulation in this population.

Acute effects of cannabis consumption on exercise performance: a systematic and umbrella review

INTRODUCTION

The goal of this systematic and umbrella review was to regroup all systematic reviews, non-systematic reviews and all original articles into one convenient publication that would facilitate the theoretical and applied scientific investigations directed on cannabis consumption and exercise performance, to update current findings on the matters, and assess evidence quality.

EVIDENCE ACQUISITION

The systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) method. A computer-based systematic search was conducted in September 2019 through the Pubmed, Scopus and SPORTDiscus databases. The reliability of the systematic search was assured by having the article selection process entirely repeated by a second author. Strength of evidence of the selected articles was assesses using a modified version of the Downs and Black Checklist.

EVIDENCE SYNTHESIS

The systematic search yielded a total of 8 peer-reviewed publications as well as 10 literature reviews. Results show that cannabis consumption prior to exercise induces decrements in performance (reduced ability to maintain effort, physical/maximal work capacity), undesired physiological responses (increased heart and breathing rate as well as myocardial oxygen demand) and neurological effects on balance (increased sway).

CONCLUSIONS

Based on the articles included in this review, the authors conclude that cannabis consumption has an ergolytic effect on exercise performance and therefore does not act as a sport performance enhancing agent as raised by popular beliefs. Thus, cannabis consumption prior to exercise should be avoided in order to maximize performance in sports. Further research should mimic modern THC dosage (150 mg).

Longitudinal associations between negative urgency, symptoms of depression, cannabis and alcohol use in veterans

There is a high comorbidity between symptoms of depression and cannabis and alcohol use in civilian and veteran populations. Prospective studies attempting to clarify the directionality of these comorbidities have yielded mixed results. Further, the relations between these constructs and impulsive personality, particularly negative urgency (NU, the tendency to act rashly when experiencing emotional distress) warrants further attention, as NU relates to symptoms of depression and alcohol and cannabis use. Importantly, NU partially accounts for the association between symptoms of depression and cannabis and alcohol problems in cross-sectional studies. This study examined alternative theories of directionality in order to better understand the longitudinal associations between symptoms of depression, NU, and cannabis or alcohol use. Three semiannual waves of data (baseline, 6-month, and 12-month) were collected in parallel assessments from a sample of Operation Enduring Freedom, Operation Iraqi Freedom, and Operation New Dawn veterans (N = 361). Autoregressive cross-lagged panel models were used to test four alternative theory-driven models about the longitudinal associations between the interaction of symptoms of depression and NU and cannabis or alcohol use. Models revealed unique direction of effects specific to each substance, such that the interaction between symptoms of depression and NU at 6 months postbaseline predicted more alcohol use at 12 months postbaseline, whereas more cannabis use at 6 months postbaseline predicted more severe symptoms of depression at 12 months postbaseline. Results suggests alternate directions of effect for cannabis and alcohol use. Future research should examine these patterns over wider assessment periods in order to see more variability and change over time. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The association between regular cannabis use, with and without tobacco co-use, and adverse cardiovascular outcomes: cannabis may have a greater impact in non-tobacco smokers

BACKGROUND

Understanding the potential impact of cannabis use on cardiovascular health is increasingly important as cannabis use rises in the U.S. Objectives: This study evaluated the associations between regular cannabis use, with and without tobacco co-use, and cardiovascular outcomes.

METHODS

Analysis of a limited dataset obtained through IBM Watson Health Explorys, a platform integrating electronic health record data. Matched controls using Mahalanobis distance within propensity score calipers were defined for: 1) cannabis-using patients (n = 8,944; 43% female); and subgroups of cannabis-using patients: 2) with an encounter diagnosis for tobacco use disorder (TUD; n = 4,682); and 3) without a TUD diagnosis (non-TUD; n = 4,262). Patients had ≥1 blood pressure measurement and blood chemistry lab result in the MetroHealth System (Cleveland, Ohio). Cannabis-using patients had an encounter diagnosis of cannabis abuse/dependence and/or ≥2 cannabis-positive urine drug screens. Control patients, with no cannabis-use-documentation, were matched to the cannabis-using patients on demographics, residential zip code median income, body mass index, and, for the total sample, TUD-status. Outcomes were encounter diagnosis (yes/no) of cerebrovascular accident (CVA), heart arrhythmia, myocardial infarction, subarachnoid hemorrhage (SAH), and all-cause mortality.

RESULTS

TUD-patients had the greatest prevalence of cardiovascular disease, regardless of cannabis-use indication. In the total sample and non-TUD subgroup, regular cannabis use was significantly associated with greater risk for CVA, arrhythmia, SAH, and mortality. In the TUD subgroup, regular cannabis use was significantly associated with greater risk for arrhythmia and SAH.

CONCLUSIONS

Cannabis use is associated with significantly greater risk of adverse cardiovascular diagnoses and overall death, particularly in non-tobacco users.

U.S. Adults With Pain, a Group Increasingly Vulnerable to Nonmedical Cannabis Use and Cannabis Use Disorder: 2001-2002 and 2012-2013

OBJECTIVE

Given changes in U.S. marijuana laws, attitudes, and use patterns, individuals with pain may be an emerging group at risk for nonmedical cannabis use and cannabis use disorder. The authors examined differences in the prevalence of nonmedical cannabis use and cannabis use disorder among U.S. adults with and without pain, as well as whether these differences widened over time.

METHODS

Data from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC, 2001-2002; N=43,093) and NESARC-III (2012-2013; N=36,309) were analyzed using logistic regression. Risk differences of past-year nonmedical cannabis use, frequent (at least three times a week) nonmedical use, and DSM-IV cannabis use disorder were estimated for groups with and without moderate to severe pain, and these risk differences were tested for change over time.

RESULTS

Any nonmedical cannabis use was more prevalent in respondents with than without pain (2001-2002: 5.15% compared with 3.74%; 2012-2013: 12.42% compared with 9.02%), a risk difference significantly greater in the 2012-2013 data than in the 2001-2002 data. The prevalence of frequent nonmedical cannabis use did not differ by pain status in the 2001-2002 survey, but was significantly more prevalent in those with than without pain in the 2012-2013 survey (5.03% compared with 3.45%). Cannabis use disorder was more prevalent in respondents with than without pain (2001-2002: 1.77% compared with 1.35%; 2012-2013: 4.18% compared with 2.74%), a significantly greater risk difference in the data from 2012-2013 than from 2001-2002.

CONCLUSIONS

The results suggest that adults with pain are a group increasingly vulnerable to adverse cannabis use outcomes, warranting clinical and public health attention to this risk. Psychiatrists and other health care providers treating patients with pain should monitor such patients for signs and symptoms of cannabis use disorder.

Medical Reasons for Marijuana Use, Forms of Use, and Patient Perception of Physician Attitudes Among the US Population

BACKGROUND

The use of marijuana for medical purposes is increasing in parallel with expanding legalization and decreased public perception of harm. Despite this increase in use, it is unclear which medical conditions patients are attempting to treat with marijuana and whether they are communicating with medical providers about their use.

OBJECTIVE

To understand the medical reasons for marijuana use, forms of marijuana used for medical purposes, and disclosure of use to physicians.

DESIGN

National, probability-based online survey.

SETTING

The USA, 2017.

PARTICIPANTS

16,280 US adults.

MAIN MEASURE

Proportion of US adults who agreed with a statement.

KEY RESULTS

A total of 9003 participants completed the survey (55% response rate). Five hundred ninety-one (7% of US adults) reported using marijuana for medical purposes. The most common medical reasons for marijuana use were anxiety (49%), insomnia (47%), chronic pain (42%), and depression (39%). The most common forms of use for all medical conditions were smoking and edibles, followed by vaping, concentrate, and topical. We found women were more likely to use marijuana for posttraumatic stress disorder, sleep, anxiety, and migraines. We did not find substantial variation in medical reasons for marijuana use by race. Among those using marijuana for medical purposes, 21% did not have a doctor. Among those with doctors, 33% did not inform them, 28% reported their doctor was neutral on their use, 32% reported their doctor was supportive, and 8% reported their doctor was not supportive. Those who lived in states where medical marijuana was illegal were less likely to disclose use to their doctor.

LIMITATION

The online format of the survey may have caused selection bias. Wording of the questions may have affected interpretation. Doctors were not queried directly, rather participants were asked about their perception of doctor attitudes.

CONCLUSION

Americans are using marijuana to treat medical conditions despite lack of evidence of efficacy.

Cannabis use prevalence among individuals with diabetes: The National Survey on Drug Use and Health, 2005-2018

BACKGROUND

The aim of the current study is to estimate cannabis use prevalence among individuals with diabetes participating in the United States (US) National Survey on Drug Use and Health (NSDUH), 2005-2018. Plausible biological mechanisms link cannabis use and metabolic regulation. Cannabis use can also alter perception and adherence to treatment especially among patients with insulin-dependent diabetes.

METHODS

The NSDUH is designed to select and recruit, annually, a representative sample of the non-institutionalized US population (12+ years). Computer-assisted self-interviews gathered information on cannabis use. The current study sample included 30,915 participants who self-reported a physician diagnosis of diabetes.

RESULTS

Prevalence of past 30-day cannabis use increased 340% among individuals with diabetes, from 1.7% (95% confidence interval [CI] = 1.1, 2.6) in 2005 to 5.8% (95% CI = 4.7, 7.1) in 2018. Results from the logistic regression model indicated that this increase was robust (odds ratio of cannabis use per NSDUH year = 1.13; 95% CI = 1.10, 1.15). The increase was observed among different sociodemographic subgroups and in states with or without medical cannabis laws.

CONCLUSIONS

As cannabis use prevalence increases, screening for use among diabetes patients is needed to optimize outcomes and reduce potential adverse effects.

Stress-induced cortical dopamine response is altered in subjects at clinical high risk for psychosis using cannabis

Stress and cannabis use are risk factors for the development of psychosis. We have previously shown that subjects at clinical high risk for psychosis (CHR) exhibit a higher striatal dopamine response to stress compared with healthy volunteers (HV), with chronic cannabis use blunting this response. However, it is unknown if this abnormal dopamine response extends to the prefrontal cortex (PFC). Here, we investigated dorsolateral PFC (dlPFC) and medial PFC (mPFC) dopamine release using [¹¹ C]FLB457 positron emission tomography (PET) and a validated stress task. Thirty-three participants completed two PET scans (14 CHR without cannabis use, eight CHR regular cannabis users [CHR-CUs] and 11 HV) while performing a Sensory Motor Control Task (control scan) and the Montreal Imaging Stress Task (stress scan). Stress-induced dopamine release (ΔBP_ND ) was defined as percent change in D_2/3 receptor binding potential between both scans using a novel correction for injected mass of [¹¹ C]FLB457. ΔBP_ND was significantly different between groups in mPFC (F(2,30) = 5.40, .010), with CHR-CUs exhibiting lower ΔBP_ND compared with CHR (.008). Similarly, salivary cortisol response (ΔAUC_I ) was significantly lower in CHR-CU compared with CHR (F(2,29) = 5.08, .013; post hoc .018) and positively associated with ΔBP_ND . Furthermore, CHR-CUs had higher attenuated psychotic symptoms than CHR following the stress task, which were negatively associated with ΔBP_ND . Length of cannabis use was negatively associated with ΔBP_ND in mPFC when controlling for current cannabis use. Given the global trend to legalize cannabis, this study is important as it highlights the effects of regular cannabis use on cortical dopamine function in high-risk youth.

Activation of cannabinoid type 1 receptors decreases the synchronization of local field potential oscillations in the hippocampus and entorhinal cortex and prolongs the interresponse time during a differential-reinforcement-of-low-rate task

Marijuana intoxication impairs neurocognitive functions. Common side effects of consuming cannabis include time distortion and memory loss. However, the underlying neurophysiological mechanisms involved in these effects remain unclear. We hypothesized that communication between the hippocampal CA1 region and medial entorhinal cortex (MEC) is essential for the transmission of temporal-associated information. We used a differential-reinforcement-of-low-rate (DRL) task, which requires subjects to press a lever at an optimal time point, to correlate the distributions of interresponse time (IRT) with local field potentials (LFPs) recorded in the CA1 and MEC under the effects of a cannabinoid type 1 (CB1) receptor agonist. We used a DRL 10-s schedule and trained the rats to withhold for 10 s before pressing a lever. Our data showed that the percentage of 12.4- to 14-s IRT events rose after activation of CB1 receptors in the MEC. In addition, gamma amplitude synchronization and CA1 theta phase-MEC gamma amplitude coupling decreased during the 6- to 14-s IRT events. These results suggest that activation of CB1 receptors in the MEC disrupt the functional connectivity between the CA1 and the MEC. This inefficient communication may result in increased IRT during a DRL schedule. Overall, we postulate that marijuana intoxication impairs the communication between the CA1 and MEC and influences behavioral performances that require precise timing ability.

[Cannabis use among the drug users with compulsory detained detoxification treatment in China]

OBJECTIVE

To explore the epidemic situation of cannabis use among drug users with compulsory detained detoxification treatment in China.

METHODS

Using the data from the Drug Abuse Population Estimation in the Key Cities of the Ministry of Public Security, we analyzed the sociodemographic characteristics and substance use of cannabis abusers with compulsory detained detoxification treatment in 55 provincial capital cities and key cities of China. Chi-square test, Fisher exact test and Kruskal-Wallis rank sum test were used to compare the prevalence of cannabis, heroin, synthetic and mixed drug use among patients with detoxification treatment, as well as the differences in polydrug use and areas among cannabis users.

RESULTS

In the study, 25 366 drug users with compulsory detained detoxification treatment were recruited, of whom 2.2% (546/25 366) used cannabis in the previous year before the treatment. The proportion of males was 83.5%, and the proportion of ethnic minorities was 41.0%. Those who received junior high school education or above accounted for 30.8%, and the unemployed accounted for 44.1%. The average age was (33.3±8.2) years, the average age of beginning drug use was (24.8±7.7) years, and the average duration between the first drug abuse and first detoxification treatment was (5.4±4.6) years. The prevalence of cannabis use was higher among those drug users who were 35-year-old and younger, ethnic minorities, employees and residents in Xinjiang. Of the cannabis users, 91.4% used polydrug, 13.6% combined with heroin alone, 42.1% combined with synthetic drugs alone and 35.7% combined with both of heroin and synthetic drugs. Of the cannabis users, 49.6% came from 3 regions: Xinjiang Uygur Autonomous Region, Jiangsu Province and Shanghai City. The cannabis users in Xinjiang had a high proportion of ethnic minorities who received junior high school education and below. Moreover, 79.6% of them combined cannabis use with heroin. The cannabis users in Jiangsu, Zhejiang and Shanghai areas had a higher proportion of ethnic Han who received better education (high school and above). Moreover, 92.7% of them combined cannabis use with methamphe-tamine.

CONCLUSION

The prevalence of cannabis use among the population with compulsory detained detoxification treatment is higher than that among drug users under surveillance, but there are obvious regional cluster effect and high possibility of polydrug abuse. Thus, it's important to strengthen the monitoring of cannabis use, to increase the control of cannabis and to formulate China's anti-cannabis policy among different population.

[Neurodevelopment and cannabis]

Brain development is a complex phenomenon, stretching from fetal life to adolescence, during which brain maturation proceeds through a series of ordered events including critical periods of plasticity. The brain is particularly sensitive to the environment during these changes. The endocannabinoid system participates directly and indirectly in these plasticity and maturation processes. The main psychoactive component of cannabis, the delta-9-tetrahydrocanabinol, can cross the placental barrier, is present in breastmilk and diffuses in the brain. It interacts with the endocannabinoid signaling, especially through the activation of cannabinoid receptors 1 CB1R, which can lead to abnormal neurodevelopmental processes and neuronal circuits functions. Therefore, exposure to cannabis in utero, in perinatal phase, as well as during the adolescence disrupts the brain maturation and can cause disturbances on the cognitive, psychotic and addictive levels that persist far beyond the period of exposure. Several factors modulate the risk of such complications, but studies performed in animal models as well as in human cohorts have shown that exposure during both the critical perinatal and adolescence phases is a risk factor per se. Current knowledge encourages the dissemination of objective information to young people, to prevent and limit early exposure and its consequences.

Cannabinoid Hyperemesis Syndrome: A Review of Potential Mechanisms

Introduction: Cannabinoids have long been known for their ability to treat nausea and vomiting. Recent reports, however, have highlighted the paradoxical proemetic effects of cannabinoids. Cannabinoid hyperemesis syndrome (CHS) is characterized by cyclical episodes of nausea and vomiting, accompanied by abdominal pain following prolonged, high-dose cannabis use, which is alleviated by hot baths and showers. Little is known about the cause of this syndrome. Discussion: Cannabinoids produce a biphasic effect on nausea and vomiting, with low doses having an antiemetic effect and high doses producing emesis. Presentation and treatment of CHS are similar to cyclical vomiting syndrome as well as chemotherapy-related anticipatory nausea and vomiting, suggesting that these phenomena may share mechanisms. The prevalence of CHS is not known because of the symptomatic overlap with other disorders and the lack of knowledge of the syndrome by the public and physicians. Treatment with typical antiemetic drugs is ineffective for CHS, but anxiolytic and sedative drugs, along with hot showers, seem to be consistently effective at reducing symptoms. The only known way to permanently end CHS, however, is abstinence from cannabinoids. Case studies and limited pre-clinical data on CHS indicate that prolonged high doses of the main psychotropic compound in cannabis, Δ9-tetrahydrocannabinol (THC), result in changes to the endocannabinoid system by acting on the cannabinoid 1 (CB1) receptor. These endocannabinoid system changes can dysregulate stress and anxiety responses, thermoregulation, the transient receptor potential vanilloid system, and several neurotransmitters systems, and are thus potential candidates for mediating the pathophysiology of CHS. Conclusions: Excessive cannabinoid administration disrupts the normal functioning of the endocannabinoid system, which may cause CHS. More clinical and pre-clinical research is needed to fully understand the underlying pathophysiology of this disorder and the negative consequences of prolonged high-dose cannabis use.

Acute neuroradiological, behavioral, and physiological effects of nose-only exposure to vaporized cannabis in C57BL/6 mice

Objective: The rapid increase of cannabis consumption reinforces the need to elucidate the health hazards of this practice. The presence of fine particulate matter in cannabis smoke and vapor poses a major concern, as it may contribute to cardiopulmonary disease. To facilitate the assessment of risks associated with cannabis inhalation, we developed and characterized a method for exposing mice to cannabis in a way that mimics the delivery of the drug to the airways of smokers. Materials and Methods: Cannabis (10.3% THC, 0.05% CBD) was vaporized to generate aerosols with a reproducible particle profile. Aerosols were acutely delivered to male, adult C57BL/6 mice via a nose-only exposure system. Serum THC levels were measured for increasing cannabis doses. Blood pressure and heart rate were recorded at baseline and following exposure. Behavioral response to cannabis inhalation in the open field was documented. Awake neurological activity upon cannabis exposure was monitored using BOLD fMRI.Results and Discussion: Cannabis aerosols contained particles with count median diameter of 243 ± 39 nm and geometric standard deviation of 1.56 ± 0.06. Blood serum THC levels increased linearly with aerosolized mass and peaked at 136 ± 5 ng/mL. Cannabis inhalation decreased heart rate and blood pressure but promoted anxiety-like behavior. Observed differences in BOLD activation volumes linked cannabis to increased awareness to sensory stimuli and reduced behavioral arousal.Conclusions: Quantified physiological, behavioral, and neurological responses served as validation for our mouse model of cannabis inhalation. Animal models of aerosol exposure will be instrumental for uncovering the health outcomes of chronic cannabis use.

Personality Traits and Psychotic Proneness Among Chronic Synthetic Cannabinoid Users

OBJECTIVE

Chronic use of synthetic cannabinoids (SCs) has been associated with a wide range of negative consequences for health including psychotic and affective disturbances. Accumulating evidence indicates that cannabinoids use may be a risk factor for schizophrenia, and chronic natural cannabis users score higher than non-users on measures of schizotypal personality traits. However, little is known regarding the personality characteristics of SC users, especially in comparison with recreational cannabis users and healthy individuals. This study aimed to examine the differences in personality characteristics and schizotypy between SC users, regular cannabis users, and non-users and to compare these measures between groups.

METHODS

Forty-two chronic SC users, 39 natural cannabis users, and 47 non-using control participants, without history of mental disorder, or current substance use diagnosis (mean age 26± 4.47 years; 23 females, 105 males), completed the Big-Five Factor Inventory (BFI), the Schizotypal Personality Questionnaire-Brief (SPQ-B), substance use history, rating scales of depression and anxiety, and a demographic questionnaire.

RESULTS

On the BFI, SC users scored higher than natural cannabis users and non-users on neuroticism, but lower on agreeableness and extraversion, and endorsed greater schizotypal symptoms on the SPQ-B. In addition, SC users had lower scores on conscientiousness than non-users, and natural cannabis users were more extroverted than non-users. Higher openness and lower conscientiousness predicted schizotypy for both SC and natural cannabis users. Finally, greater neuroticism predicted schizotypy for natural cannabis users, and introversion predicted schizotypy for non-users.

CONCLUSIONS

These results show that chronic SC users differ from natural cannabis users and non-users on dimensions of specific personality traits and schizotypy that may indicate psychotic proneness.

THC Exposure is Reflected in the Microstructure of the Cerebral Cortex and Amygdala of Young Adults

The endocannabinoid system serves a critical role in homeostatic regulation through its influence on processes underlying appetite, pain, reward, and stress, and cannabis has long been used for the related modulatory effects it provides through tetrahydrocannabinol (THC). We investigated how THC exposure relates to tissue microstructure of the cerebral cortex and subcortical nuclei using computational modeling of diffusion magnetic resonance imaging data in a large cohort of young adults from the Human Connectome Project. We report strong associations between biospecimen-defined THC exposure and microstructure parameters in discrete gray matter brain areas, including frontoinsular cortex, ventromedial prefrontal cortex, and the lateral amygdala subfields, with independent effects in behavioral measures of memory performance, negative intrusive thinking, and paternal substance abuse. These results shed new light on the relationship between THC exposure and microstructure variation in brain areas related to salience processing, emotion regulation, and decision making. The absence of effects in some other cannabinoid-receptor-rich brain areas prompts the consideration of cellular and molecular mechanisms that we discuss. Further studies are needed to characterize the nature of these effects across the lifespan and to investigate the mechanistic neurobiological factors connecting THC exposure and microstructural parameters.

Psychiatric comorbidity in adolescent use and poly-use of combustible, vaporized, and edible cannabis products

Cannabis legalization and commercialization has resulted in novel alternative cannabis products on the market, including edible and vaporized cannabis, which may appeal to youth with psychiatric problems. Psychiatric comorbidity in adolescent use and poly-use (i.e., use of >2 products) of combustible, edible, and vaporized cannabis products has largely gone uninvestigated. This 2015 cross-sectional survey of Los Angeles, California area adolescents (Mage = 16.1, N = 3177) characterized associations of various psychiatric problems with use and poly-use of combustible, edible, and vaporized cannabis. Exposure variables included past 30-day non-cannabis substance use (alcohol, e-cigarettes, combustible cigarettes, and nonmedical prescription opioid and stimulant use; yes/no), and psychiatric problems including past-week depressive symptom frequency, past 6-month ADHD symptom and conduct problem frequency, anhedonia, and five dimensions of impulsivity (sensation seeking, perseverance, lack of premeditation, positive urgency, and negative urgency). Outcome variables included past 30-day use (yes/no) of combustible, edible, and vaporized cannabis, independently, and number of cannabis products used (single, dual-use, poly-use). Results showed that all forms of non-cannabis substance use (ORs range: 13.7-36.1) and all psychiatric symptoms and traits (ORs in SD units range: 1.1-2.1) were positively associated with combustible, edible, and vaporized cannabis product use. The magnitude of comorbidity did not significantly differ by cannabis product type used in most cases. Psychiatric comorbidity was typically stronger in poly-product than single-product cannabis use and greater for externalizing-type than internalizing-type psychiatric problems. Practitioners, policy makers, and scientists should be aware that pervasive psychiatric comorbidity may be observed across the spectrum of cannabis product use among adolescents, particularly poly-product users.

Acute and residual mood and cognitive performance of young adults following smoked cannabis

OBJECTIVES

To examine acute and residual mood and cognitive performance in young adult regular cannabis users following smoked cannabis.

METHODS

Ninety-one healthy young adults completed this double-blind, placebo-controlled, parallel-groups study. Participants were randomized to receive active (12.5% THC) or placebo cannabis with a 2:1 allocation ratio, and mood [Profile of Mood States (POMS)] and cognitive performance [Hopkins Verbal Learning Test - Revised (HVLT-R), Digit Symbol Substitution Test (DSST), Continuous Performance Test (CPT), grooved pegboard (GPB)] were assessed before and 1, 24, and 48 (h) after smoking cannabis ad libitum. High and Low THC groups were based on blood THC concentrations.

RESULTS

One hour after smoking cannabis, compared to Placebo, in both the High and Low THC groups, there were increases in POMS Arousal and Positive Mood, and in the High THC group only, increases in Confusion, Friendliness, and Elation, and a decrease in Fatigue. Increases in Friendliness and Elation in the High THC group remained significant for 24 h. The only significant acute effect of cannabis on cognition was a decrease in the percent of words retained in the HVLT-R in the High THC group compared to Placebo (mean difference = 15.8%, 95% CI = 3.6-28.0%, p = 0.006). Unexpectedly, compared to Placebo, both the High and Low THC groups improved in DSST performance at 48 h (p ≤ 0.016).

CONCLUSIONS

Under the present experimental conditions, in young regular cannabis users, smoking cannabis ad libitum had significant effects on mood, some of which persisted 24 h later, yet minimal effects on cognition, and no evidence of residual cognitive impairment.

Maternal exposure to Δ9-tetrahydrocannabinol impairs female offspring glucose homeostasis and endocrine pancreatic development in the rat

Recent reports indicate that 7% of pregnant mothers in North America use cannabis. This is concerning given that in utero exposure to Δ9-tetrahydrocannabinol (Δ9-THC), the main psychoactive component in cannabis, causes fetal growth restriction and may alter replication and survival of pancreatic β-cells in the offspring. Accordingly, we hypothesized that maternal exposure to Δ9-THC during pregnancy would impair postnatal glucometabolic health of offspring. To test this hypothesis, pregnant Wistar rats were treated with daily intraperitoneal injections of either 3 mg/kg Δ9-THC or vehicle from gestational day 6 to birth. Offspring were subsequently challenged with glucose and insulin at 5 months of age to assess glucose tolerance and peripheral muscle insulin sensitivity. Female offspring exposed to Δ9-THC in utero were glucose intolerant, associated with blunted insulin response in muscle and increased serum insulin concentration 15 min after glucose challenge. Additionally, pancreata from male and female offspring were harvested at postnatal day 21 and 5 months of age for assessment of endocrine pancreas morphometry by immunostaining. This analysis revealed that gestational exposure to Δ9-THC reduced the density of islets in female, but not male, offspring at postnatal day 21 and 5 months, culminating in reduced β-cell mass at 5 months. These results demonstrate that fetal exposure to Δ9-THC causes female-specific impairments in glucose homeostasis, raising concern regarding the metabolic health of offspring, particularly females, exposed to cannabis in utero.

Do Adolescents Use Substances to Relieve Uncomfortable Sensations? A Preliminary Examination of Negative Reinforcement among Adolescent Cannabis and Alcohol Users

Alcohol and cannabis use are highly prevalent among adolescents and associated with negative consequences. Understanding motivations behind substance use in youth is important for informing prevention and intervention efforts. The present study aims to examine negative reinforcement principles of substance use among adolescent cannabis and alcohol users by pairing a cue reactivity paradigm with an aversive interoceptive stimulus. Adolescents (ages 15–17), classified as controls (CTL; n = 18), cannabis and/or alcohol experimenters (CAN+ALC-EXP; n = 16), or individuals meeting clinical criteria for cannabis and/or alcohol use disorder (CAN+ALC-SUD; n = 13) underwent functional magnetic resonance imaging during which they experienced an aversive interoceptive probe delivered via breathing load while simultaneously performing a cue reactivity paradigm. Participants also provided self-report ratings of how their substance use is positively or negatively reinforced. While experiencing the breathing load, CAN+ALC-SUD exhibited greater (p < 0.05) deactivation in the right amygdala, the left inferior frontal gyrus, and the left parahippocampal gyrus than CAN+ALC-EXP and CTL, who did not differ. Across all substance users, activation during the breathing load within the left parahippocampal gyrus negatively correlated with cannabis and alcohol lifetime use episodes and the left inferior frontal gyrus activity negatively correlated with lifetime alcohol use episodes. CAN+ALC-SUD reported experiencing more positive and negative reinforcement of using their substance of choice than CAN+ALC-EXP; both user groups reported higher levels of positive than negative reinforcement. Adolescents with a cannabis/alcohol use disorder demonstrate an altered response to interoceptive perturbations. However, adolescent cannabis/alcohol use does not appear to be driven by negative reinforcement, as viewing substance images did not dampen this response. Based on self-report data, the experience of positive reinforcement may be stronger for adolescents. Future studies should examine whether positive reinforcement contributes to adolescent substance use.

Sex-related differences in subjective, but not neural, cue-elicited craving response in heavy cannabis users

BACKGROUND

Studies indicate that female cannabis users progress through the milestones of cannabis use disorder (CUD) more quickly than male users, likely due to greater subjective craving response in women relative to men. While studies have reported sex-related differences in subjective craving, differences in neural response and the relative contributions of neural and behavioral response remain unclear.

METHODS

We examined sex-related differences in neural and behavioral response to cannabis cues and cannabis use measures in 112 heavy cannabis users (54 females). We used principal component analysis to determine the relative contributions of neural and behavioral response and cannabis use measures.

RESULTS

We found that principal component (PC) 1, which accounts for the most variance in the dataset, was correlated with neural response to cannabis cues with no differences between male and female users (p = 0.21). PC2, which accounts for the second-most variance, was correlated with subjective craving such that female users exhibited greater subjective craving relative to male users (p = 0.003). We also found that CUD symptoms correlated with both PC1 and PC2, corroborating the relationship between craving and CUD severity.

CONCLUSIONS

These results indicate that neural activity primarily underlies response to cannabis cues and that a complex relationship characterizes a convergent neural response and a divergent subjective craving response that differs between the sexes. Accounting for these differences will increase efficacy of treatments through personalized approaches.

A preliminary test of a brief intervention to lessen young adults' cannabis use: Episode-level smartphone data highlights the role of protective behavioral strategies and exercise

Brief interventions are increasingly being used to help young adults to moderate their cannabis use. We conducted a randomized clinical trial of a brief (4 weekly sessions), in-person intervention that included a smartphone application that reinforced the use of protective behavioral strategies (PBSs) to lessen cannabis use. Young adults (N = 37; 24 men) who regularly used cannabis were randomized to 2 intervention conditions rooted in cognitive-behavioral therapy (CBT) and motivational enhancement therapy (MET). Along with learning CBT + MET strategies, participants in 1 of the conditions were instructed to engage in exercise. All participants used smartphone-based ecological momentary assessment to provide episode-level reports about use of cannabis and PBSs. Two multilevel structural equation models were run to test the study hypotheses that (a) cannabis use would be reduced over the course of the 6-month study, (b) reductions would be moderated by intervention condition, and (c) episode-level PBS use would predict episode-level cannabis use. Participants reduced their cannabis use by approximately 1 half of a standard joint per time point. The MET + CBT + Exercise condition reduced cannabis use to a greater degree than did the MET + CBT condition. With episode-level PBS use in the model, reductions in cannabis use were independent of intervention condition. Our findings suggest that young adults will engage with a smartphone app that serves as a component of an in-person intervention to moderate their cannabis use. Intervention content that promotes the use of PBSs and exercise facilitates reductions in cannabis use. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Cannabis use among youth in the United States, 2004-2016: Faster rate of increase among youth with depression

BACKGROUND

Cannabis use has significant negative consequences for youth. Depression is associated with greater cannabis use among adults but less is known about cannabis use and depression among youth. This study investigated whether depression is associated with increased cannabis use among youth in the United States (US), overall and by demographics, and examined trends in cannabis use by depression status among youth from 2004 to 2016.

METHODS

Data were from the 2004-2016 National Survey on Drug Use and Health (NSDUH), annual cross-sectional national samples of US persons 12 and older. The analytic sample included respondents aged 12-17 (total combined n=204,102). First, the prevalence of past-month cannabis use by past-year depression status among youth was examined, overall and by demographic subgroups, using pooled data from 2004-2016. Next, linear time trends of past-month cannabis use were assessed by depression status from 2004 to 2016 using logistic regression models with continuous year as the predictor. Models with year-by-depression status interaction terms assessed differential time trends for those with and without depression.

RESULTS

From 2004-2016, cannabis use increased both among youth with and without depression. Cannabis use increased significantly more rapidly among youth with (8.45% to 11.65%), compared to without, depression (4.28% to 4.71%). Youth with depression were more than twice as likely to report cannabis use (12.86% versus 6.40%), relative to those without depression.

CONCLUSIONS

Cannabis use was more than twice as common and increased more rapidly from 2004 to 2016 among youth with depression compared to youth without depression.

Patients Who Have Cannabis Use Disorder Have Higher Rates of Venous Thromboemboli, Readmission Rates, and Costs Following Primary Total Knee Arthroplasty

BACKGROUND

Studies have shown that cannabis can interfere with hematological parameters and platelet morphology. The purpose of this study is to investigate whether patients with cannabis use disorder undergoing primary total knee arthroplasty (TKA) have higher rates of (1) venous thromboemboli (VTEs); (2) readmissions; and (3) costs.

METHODS

Study group patients undergoing primary TKA were identified from a large, nationwide database. Patients who had a history of VTEs, deep vein thromboses (DVTs), pulmonary emboli (PEs), and coagulopathies before their TKA were excluded. Study group patients were matched to controls in a 1:4 ratio by age, sex, a comorbidity index, and medical comorbidities. The query yielded 18,388 patients (cannabis = 3680; controls = 14,708). Outcomes analyzed included rates of 90-day VTEs, DVTs, and PEs, in addition to 90-day readmissions and costs. A P value less than .01 was considered statistically significant.

RESULTS

Patients who have cannabis use disorder were found to have significantly higher incidence and odds (2.79% vs 1.78%; odds ratio [OR], 1.58; P < .0001) of VTEs, DVTs (2.41% vs 1.44%; OR, 1.68; P < .0001), and PEs (0.97% vs 0.62%; P = .01). Readmissions were significantly higher (27.03% vs 23.18%; OR, 1.22; P < .0001) in patients who have cannabis use disorder. Patients with cannabis use disorder have significantly higher day of surgery ($14,024.88 vs $12,127.49; P < .0001) and 90-day costs ($19,155.45 vs $16,315.00; P < .0001).

CONCLUSION

This study found that patients who have a cannabis use disorder have higher rates of thromboembolic complications, readmission rates, and costs following primary TKA compared to a matched cohort.

Prevalence of Cannabis Withdrawal Symptoms Among People With Regular or Dependent Use of Cannabinoids: A Systematic Review and Meta-analysis

IMPORTANCE

Cannabis withdrawal syndrome (CWS)-a diagnostic indicator of cannabis use disorder-commonly occurs on cessation of heavy and prolonged cannabis use. To date, the prevalence of CWS syndrome has not been well described, nor have the factors potentially associated with CWS.

OBJECTIVES

To estimate the prevalence of CWS among individuals with regular or dependent use of cannabinoids and identify factors associated with CWS.

DATA SOURCES

A search of literature from database inception to June 19, 2019, was performed using MEDLINE, Embase, PsycINFO, Web of Science, the Cumulative Index to Nursing and Allied Health Literature, ProQuest, Allied and Complementary Medicine, and Psychiatry online, supplemented by manual searches of reference lists of included articles.

STUDY SELECTION

Articles were included if they (1) were published in English, (2) reported on individuals with regular use of cannabinoids or cannabis use disorder as a primary study group, (3) reported on the prevalence of CWS or CWS symptoms using a validated instrument, (4) reported the prevalence of CWS, and (5) used an observational study design (eg, cohort or cross-sectional).

DATA EXTRACTION AND SYNTHESIS

All abstracts, full-text articles, and other sources were reviewed, with data extracted in duplicate. Cannabis withdrawal syndrome prevalence was estimated using a random-effects meta-analysis model, alongside stratification and meta-regression to characterize heterogeneity.

MAIN OUTCOMES AND MEASURES

Cannabis withdrawal syndrome prevalence was reported as a percentage with 95% CIs.

RESULTS

Of 3848 unique abstracts, 86 were selected for full-text review, and 47 studies, representing 23 518 participants, met all inclusion criteria. Of 23 518 participants included in the analysis, 16 839 were white (72%) and 14 387 were men (69%); median (SD) age was 29.9 (9.0) years. The overall pooled prevalence of CWS was 47% (6469 of 23 518) (95% CI, 41%-52%), with significant heterogeneity between estimates (I2 = 99.2%). When stratified by source, the prevalence of CWS was 17% (95% CI, 13%-21%) in population-based samples, 54% in outpatient samples (95% CI, 48%-59%), and 87% in inpatient samples (95% CI, 79%-94%), which were significantly different (P < .001). Concurrent cannabis (β = 0.005, P < .001), tobacco (β = 0.002, P = .02), and other substance use disorders (β = 0.003, P = .05) were associated with a higher CWS prevalence, as was daily cannabis use (β = 0.004, P < .001).

CONCLUSIONS AND RELEVANCE

These findings suggest that cannabis withdrawal syndrome appears to be prevalent among regular users of cannabis. Clinicians should be aware of the prevalence of CWS in order to counsel patients and support individuals who are reducing their use of cannabis.

Toward a Typology of Normative Drug Users Based on Levels of Functioning, Justifications and Types of Use

The study explores 29 individuals who described themselves as functioning normatively while using drugs on a regular basis. They defined their use as intensive, constant, and playing a significant part in their normative lives. The content analysis revealed a typology consisting of four different types of normative users: the socially connected users, the better coping users, the ambivalent users, and the recovering users. This typology was created on the basis of three axes: level of functioning, justification of use, style of use. Our typology highlights the differences between normative users with varying patterns of drug usage and levels of functioning, ranging from users who claim that drug use causes them no harm to those who acknowledge that drug use has significantly damaged their functioning. This typology places particular emphasis on normative users who are experiencing a range of difficulties and need specific forms of therapy to preserve their normative lives.

Exposure to Cannabis Marketing in Social and Traditional Media and Past-Year Use Among Adolescents in States With Legal Retail Cannabis

PURPOSE

The objective of this study was to examine adolescents' self-reported exposure to cannabis marketing in states with legalized cannabis and its association with past-year cannabis use.

METHODS

We conducted a cross-sectional, online panel survey of 469 adolescents aged 15-19 years residing in four states with legal retail cannabis for adult use. Adolescents self-reported exposure to cannabis marketing on social or traditional media (i.e., outdoor or print) and past-year cannabis use. Logistic regression generated estimated odds of youths' past-year cannabis use by marketing exposure after adjusting for demographic factors and cannabis-related social norms.

RESULTS

Exposure to cannabis marketing on Facebook, Twitter, and Instagram was associated with increased odds of past-year cannabis use of 96% (95% confidence interval [CI]: 15%-234%), 88% (95% CI: 11%-219%), and 129% (95% CI: 32%-287%), respectively. Odds of past-year cannabis use increased by 48% (95% CI: 16%-87%) with each additional social media platform where adolescents reported exposure.

CONCLUSIONS

Despite restrictions that prohibit cannabis advertising on social media, adolescents are exposed to cannabis marketing via social media, and this exposure is associated with recent cannabis use. States should consider further regulation of cannabis marketing on social media.

Marijuana Use and Potential Implications of Marijuana Legalization

Most states in the United States have legalized medical and/or recreational cannabis in response to public demand. Trends in states adopting such legislation demonstrate an increasing prevalence of cannabis use coincident to decreasing perceptions of risk of harm from cannabis products. When providing anticipatory guidance, pediatricians should be prepared to address childhood unintentional ingestion management and prevention, adolescent problem use, and cannabis as an alternative therapy for seizure disorders and other conditions.