Association Between Recreational Marijuana Legalization in the United States and Changes in Marijuana Use and Cannabis Use Disorder From 2008 to 2016

Cannabis Use Disorder Associated With Increased Risk of Postoperative Complications After Hip or Knee Arthroplasties: A Meta-analysis of Observational Studies

INTRODUCTION

With the legalization of marijuana in the United States, the number of patients with cannabis use disorder (CUD) in the joint arthroplasty population has increased markedly. The primary purpose of this meta-analysis was to determine whether there were differences in clinical and economic outcomes after total joint arthroplasty (TJA) between patients with and without perioperative CUD.

METHODS

We searched PubMed, Embase, Scopus, and Web of Science databases up to July 2018 to identify all eligible studies investigating the association of CUD with postoperative outcomes in patients undergoing TJA. Postoperative outcomes assessed consisted of complications, readmission, length of stay (LOS), implant revision, and cost of care. For dichotomous outcomes, pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated using a random effects model.

RESULTS

We identified 10 retrospective cohort studies with a total of 17,981,628 study participants. Patients with CUD had significantly higher odds of medical complications (OR 1.33 [95% CI 1.07 to 1.66], P = 0.01) and implant-related complications (OR 1.75 [95% CI: 1.64 to 1.88], P < 0.00001) than noncannabis users. Specifically, CUD was associated with significantly increased odds of cardiac complications (OR 1.95 [95% CI 1.50 to 2.54], P < 0.00001), cerebrovascular accidents (OR 2.06 [95% CI 1.66 to 2.57], P < 0.00001), postoperative infections (OR 1.68 [95% CI 1.34 to 2.10], P < 0.00001), periprosthetic fracture (OR 1.42 [95% CI 1.19 to 1.70], P < 0.0001), mechanical loosening (OR 1.54 [95% CI 1.42 to 1.66], P < 0.00001), and dislocation/instability (OR 1.88 [95% CI 1.32 to 2.68], P = 0.0005). Longer LOS and higher cost of care were also found in patients with CUD.

CONCLUSION

This study strengthens the body of evidence that patients with CUD face higher risk of postoperative complications and greater financial burden after knee and hip arthroplasties. Physicians should inform patients about adverse outcomes and undertake appropriate risk adjustments before elective orthopaedic surgery.

LEVEL OF EVIDENCE

Level III.

Cannabis use trajectories over time in relation to minority stress and gender among sexual and gender minority people

Substance use disparities among sexual and gender minority (SGM) people are attributed to minority stress, but few studies have examined minority stress and cannabis use over time or investigated differences in cannabis use trajectories by less-studied gender subgroups. We examined if longitudinal cannabis use trajectories are related to baseline minority stressors and if gender differences persisted after accounting for minority stress. Cannabis use risk was measured annually over four years (2017-2021) within a longitudinal cohort study of SGM adults in the United States (N = 11,813). Discrimination and victimization, internalized stigma, disclosure and concealment, and safety and acceptance comprised minority stress (n = 5,673). Latent class growth curve mixture models identified five cannabis use trajectories: 'low or no risk', 'low moderate risk', 'high moderate risk', 'steep risk increase', and 'highest risk'. Participants who reported past-year discrimination and/or victimization at baseline had greater odds of membership in any cannabis risk category compared to the 'low risk' category (odds ratios [OR] 1.17-1.33). Internalized stigma was related to 'high moderate' and 'highest risk' cannabis use (ORs 1.27-1.38). After accounting for minority stress, compared to cisgender men, gender expansive people and transgender men had higher odds of 'low moderate risk' (ORs 1.61, 1.67) or 'high moderate risk' (ORs 2.09, 1.99), and transgender men had higher odds of 'highest risk' (OR 2.36) cannabis use. This study indicates minority stress is related to prospective cannabis use risk trajectories among SGM people, and transgender men and gender expansive people have greater odds of trajectories reflecting cannabis use risk.

Cross-ancestry genetic investigation of schizophrenia, cannabis use disorder, and tobacco smoking

Individuals with schizophrenia frequently experience co-occurring substance use, including tobacco smoking and heavy cannabis use, and substance use disorders. There is interest in understanding the extent to which these relationships are causal, and to what extent shared genetic factors play a role. We explored the relationships between schizophrenia (Scz; European ancestry N = 161,405; African ancestry N = 15,846), cannabis use disorder (CanUD; European ancestry N = 886,025; African ancestry N = 120,208), and ever-regular tobacco smoking (Smk; European ancestry N = 805,431; African ancestry N = 24,278) using the largest available genome-wide studies of these phenotypes in individuals of African and European ancestries. All three phenotypes were positively genetically correlated (rgs = 0.17-0.62). Genetic instrumental variable analyses suggested the presence of shared heritable factors, but evidence for bidirectional causal relationships was also found between all three phenotypes even after correcting for these shared genetic factors. We identified 327 pleiotropic loci with 439 lead SNPs in the European ancestry data, 150 of which were novel (i.e., not genome-wide significant in the original studies). Of these pleiotropic loci, 202 had lead variants which showed convergent effects (i.e., same direction of effect) on Scz, CanUD, and Smk. Genetic variants convergent across all three phenotypes showed strong genetic correlations with risk-taking, executive function, and several mental health conditions. Our results suggest that both shared genetic factors and causal mechanisms may play a role in the relationship between CanUD, Smk, and Scz, but longitudinal, prospective studies are needed to confirm a causal relationship.

Cannabinoids and the heart-a psychiatrist's perspective

The partial legalization of cannabis in Germany in 2024 will affect both medical and recreational use of cannabis. Tetrahydrocannabinol (THC), the main psychoactive component of the cannabis plant, influences heart rate and blood pressure through the endocannabinoid system. Acute and chronic use can pose cardiovascular risks. There is evidence of a link between cannabis use and cardiovascular events such as stroke and myocardial infarction, although studies show conflicting results. The non-psychoactive cannabidiol (CBD) could have anti-inflammatory and antioxidant effects. Smoking cannabis poses additional cardiovascular risks similar to tobacco. Given these risks, cardiologists should routinely ask their patients about possible cannabis use and inform them about the potential cardiovascular dangers. The article also highlights the psychiatric risks of cannabis use, including dependence and psychosis, and emphasizes the need for interdisciplinary collaboration between cardiologists and psychiatrists to effectively manage cannabis-related health problems.

Examining the Popularity, Content, and Intersections With the Substance Abuse and Mental Health Services Administration's Definition of Recovery in a Nonclinical Online Cannabis Cessation Community: Infodemiology Study of Reddit Posts

BACKGROUND

Cannabis consumption has increased in recent years, as has cannabis use disorder. While researchers have explored public online community discussions of active cannabis use, less is known about the popularity and content of publicly available online communities intended to support cannabis cessation.

OBJECTIVE

This study aims to examine the level of engagement and dominant content of an online community for cannabis cessation through 3 specific aims. First, we examine the use of a subreddit cannabis cessation community (r/leaves) over time to evaluate the popularity of this type of resource for individuals who want to stop using cannabis. Second, we examine the content of posts in the community to identify popular topics related to cessation. Third, we compare the thematic findings relative to the 4 domains of recovery defined by the Substance Abuse and Mental Health Services Administration (SAMHSA). By examining these 3 gaps, we take the initial steps toward understanding the experiences being shared online among individuals interested in cannabis cessation and compare them with the principles outlined in the SAMHSA definition of recovery.

METHODS

Using the Pushshift application programming interface, we collected the count of posts by year between 2011 and 2021 and the narrative of the 100 posts with the most comments per year in a popular cannabis cessation-focused subreddit (r/leaves). A linear model and a nonlinear model were compared to evaluate change in the number of posts by year. Mixed natural language processing and qualitative analyses were applied to identify top terms, phrases, and themes present in posts over time. Overlap between themes and the 4 SAMHSA domains of recovery (health, purpose, community, and home) were examined.

RESULTS

The number of annual posts in r/leaves increased from 420 in 2011 to 34,841 in 2021 (83-fold increase), with exponential growth since 2018. The term that was the most common across posts was "smoke" (2019 posts). Five major themes were identified, and a narrative arc was represented, from motivations and perceived benefits of cannabis use to the negative consequences of use, strategies to change behaviors, and the positive and negative consequences of change. There was substantial overlap between these 5 themes and 3 of SAMHSA's 4 domains of recovery: health, purpose, and community. However, the domain of home was less commonly identified.

CONCLUSIONS

Engagement in this online cannabis support community appears to be increasing. Individuals using this forum discussed several topics, including multiple aspects of recovery defined by the SAMHSA. Online communities, such as this one may, serve as an important pathway for individuals seeking to reduce or cease their consumption of cannabis.

[Impact of the legalization of recreational cannabis on the risk of psychosis: A systematic review of the literature]

INTRODUCTION

Cannabis is the most consumed illicit substance in Europe. Although its sale and use remain generally prohibited, European public policies have evolved in recent years by legalizing cannabis for medical use and considering its legalization for recreational use. However, in the literature there are arguments in favor of a particular relationship between cannabis consumption and the development of psychotic symptoms. Thus, since cannabis consumption tends to increase with legalization, the aim of this review was to investigate the impact of the legalization of cannabis for recreational use on the risk of psychosis in regions of the world already concerned.

METHOD

A systematic review of the literature was carried out in April 2024 in the PubMed-Medline database according to PRISMA criteria. The sequence of keywords used was as follows: ("Cannabis" [Mesh] or cannabis) AND (("Psychotic Disorders" [Mesh] or Psychotic Disorders) or ("Schizophrenia Spectrum and Other Psychotic Disorders" [Mesh]) or ("Schizophrenia" [Mesh] or Schizophrenia)) AND legal use. The inclusion criteria applied for the selection of articles in this systematic review were: (1) any article investigating the potential impact of the legalization of cannabis for recreational use on the risk of psychosis (any type of psychosis diagnosed according to ICD-9, ICD-10, DSM-4 or DSM-5) by the intermediary of epidemiological (incidence or prevalence) and/or clinical (ambulatory consultations, emergency visits or hospitalizations) criteria, (2) any type of study (cross-sectional, longitudinal, prospective, retrospective, interventional and experimental) with a methodology including a temporal and/or geographic comparison of the risk of psychosis associated with the legalization of cannabis for recreational use with the exception of literature reviews and clinical cases descriptions, (3) absence of limitation for the age of the populations studied and for the date of publication, and (4) articles written in English or French. After evaluation by the two authors of the 160 articles identified, seven studies investigating the impact of the legalization of cannabis for recreational use on the risk of psychosis were included in this systematic literature review.

RESULTS

Four of the studies showed no increase in the use of health services for psychosis following the legalization of cannabis for recreational use whereas three other studies highlighted a negative impact of the legalization of cannabis for recreational use on the risk of psychosis. All of these studies were carried out in North America and were characterized by a low level of scientific evidence.

CONCLUSION

Given the complexity of assessing the impact of the legalization of cannabis for recreational use on the risk of psychosis, additional investigations through studies of better scientific quality are essential. However, based on the data already available, there is some evidence that there is a potential negative impact on mental health due to the legalization of cannabis for recreational use. In this context, in the event of legalization of cannabis for recreational use it seems essential to recommend lower risk use of cannabis (limit the frequency of use, delay the age of first consumption, control the THC content of products and promote prevention/education). Finally, in order to enable dynamic evolution of public health strategies the establishment of continued monitoring is essential as cannabis legalization evolves.

Understanding of pharmacy students' knowledge of cannabis use disorders in recreational vs non-recreational use states

INTRODUCTION

Currently, the trend of legalizing recreational cannabis across the United States is experiencing rapid expansion. Cannabis Use Disorder (CUD) is a pattern of cannabis use leading to clinically significant impairment, manifested by at least two of the 11 criteria on DSM-5. The objective of this study is to compare the knowledge of CUD among pharmacy students attending pharmacy schools in recreational cannabis-legalized states to nonlegalized states.

METHODS

This was a survey-based study using validated questionnaires distributed among students from ACPE-accredited pharmacy schools in the United States. The survey included a CUD knowledge section followed by section on student characteristics. Individual item knowledge scores for each question were assessed as well as the total knowledge score. Adjusted linear regression model was used to evaluate knowledge scores between legalized and nonlegalized states.

RESULTS

A total of 513 students initiated the survey and 408 completed responses with 153 from recreational cannabis legalized states and 255 from nonlegalized states. The mean knowledge score in RC-legalized states was higher than nonlegalized states. After adjusting for covariates, the knowledge of pharmacy students in recreational cannabis legalized states were 40% higher than in nonlegalized states.

CONCLUSION

For future patient requirements, it may be necessary for students to receive formal education in pharmacy schools regarding CUD so that they can proficiently assist with their patient needs. Given that pharmacy students might relocate to different states, it is essential to ensure that they possess a comprehensive understanding of the specific regulations CUD across the United States.

Discriminative validity of a substance use symptom checklist for moderate-severe DSM-5 cannabis use disorder (CUD) in primary care settings

Background

The prevalence of cannabis use disorder (CUD) is increasing in the US and primary care providers need tools to identify patients with moderate-severe CUD to facilitate treatment. A single-item screen for cannabis (SIS-C) has outstanding discriminative validity for CUD. However, because the prevalence of moderate-severe CUD is typically low, the probability that an average patient who screens positive for daily cannabis has moderate-severe cannabis use disorder is low, making follow-up assessment important.

Methods

This study reports the discriminative validity of a DSM-5 Substance Use Symptom Checklist ("Checklist") for moderate-severe CUD among 498 primary care patients who reported daily cannabis use on the SIS-C. We evaluated the performance of the Checklist (score 0-11) completed during routine care, compared to ≥4 DSM-5 CUD symptoms (moderate-severe CUD) on the Composite International Diagnostic Interview Substance Abuse Module from a confidential survey (reference standard). We estimated areas under receiver operating curve (AUROC), sensitivities, specificities, and post-test probabilities.

Results

Of 498 eligible patients, 17 % met diagnostic criteria for moderate-severe CUD. The Checklist's AUROC for moderate-severe CUD was 0.77 (95 % CI: 0.71-0.83), and Checklist scores of 1-2 balanced sensitivity and specificity. Among patients from a population with average prevalence of CUD before screening (~6 % prevalence) and daily use on the SIS-C, a Checklist score of 3 indicated a post-test probability of 82.1 %.

Conclusion

Overall performance of the Checklist was good and the high specificity made it useful for identifying patients likely to have moderate-severe CUD among those at average risk.

Effects of Recreational Cannabis Legalization on Mental Health: Scoping Review

OBJECTIVE

Recreational cannabis legalization (RCL) is expanding rapidly. RCL's effects on mental health issues are of particular concern because cannabis use is more frequent among people receiving psychiatric care and is associated with several psychiatric disorders. The authors conducted a scoping review to examine the evidence and discern gaps in the literature concerning the effects of RCL on mental health and to assess the factors responsible for an observed heterogeneity in research results.

METHODS

This scoping literature review followed PRISMA guidelines. Five databases-MEDLINE, CINAHL, Embase, APA PsycInfo, and Web of Science-were searched for English- or French-language reports published between January 1, 2012, and April 30, 2023.

RESULTS

Twenty-eight studies from the United States and Canada were found. The studies were classified by category of the study's data (patients receiving psychiatric care [k=1], death records [k=4], emergency department or hospital records [k=10], and the general population [k=13]) and by the diagnosis (schizophrenia or psychoses, mood disorders, anxiety disorders and symptoms, suicide or suicidal ideation, or other mental health issues) examined. The review findings revealed a paucity of research and indicated mixed and largely inconclusive results of the studies examined. Research gaps were found in the examination of potential changes in cannabis use patterns among people receiving psychiatric care and in the availability of longitudinal studies.

CONCLUSIONS

Clinicians, researchers, and policy makers need to collaborate to address the research gaps and to develop evidence-based policies that reflect a thorough understanding of the effects associated with RCL.

"Weeding out" violence? Translational perspectives on the neuropsychobiological links between cannabis and aggression

Recent shifts in societal attitudes towards cannabis have led to a dramatic increase in consumption rates in many Western countries, particularly among young people. This trend has shed light on a significant link between cannabis use disorder (CUD) and pathological reactive aggression, a condition involving disproportionate aggressive and violent reactions to minor provocations. The discourse on the connection between cannabis use and aggression is frequently enmeshed in political and legal discussions, leading to a polarized understanding of the causative relationship between cannabis use and aggression. However, integrative analyses from both human and animal research indicate a complex, bidirectional interplay between cannabis misuse and pathological aggression. On the one hand, emerging research reveals a shared genetic and environmental predisposition for both cannabis use and aggression, suggesting a common underlying biological mechanism. On the other hand, there is evidence that cannabis consumption can lead to violent behaviors while also being used as a self-medication strategy to mitigate the negative emotions associated with pathological reactive aggression. This suggests that the coexistence of pathological aggression and CUD may result from overlapping vulnerabilities, potentially creating a self-perpetuating cycle where each condition exacerbates the other, escalating into externalizing and violent behaviors. This article aims to synthesize existing research on the intricate connections between these issues and propose a theoretical model to explain the neurobiological mechanisms underpinning this complex relationship.

Clinician perspectives on adolescent cannabis-related beliefs and behaviors following recreational cannabis legalization

BACKGROUND

As more states legalize cannabis, studies are needed to understand the potential impacts of recreational cannabis legalization (RCL) on adolescents from the perspective of clinicians who care for them.

METHODS

This qualitative study characterized clinician perspectives on whether cannabis legalization is associated with changes in adolescents' cannabis use beliefs, behaviors, and consequences. Semi-structured qualitative interviews were conducted with 32 clinicians in a large healthcare organization from 9/6/2022-12/21/2022. Video-recorded interviews were transcribed and analyzed using thematic analysis.

RESULTS

The 32 participants (56.3 % female, mean [SD] age, 45.9 [7.6] years; 65.3 % non-Hispanic White) were from Addiction Medicine (n = 13), Psychiatry/Mental Health (n = 7), Pediatrics (n = 5), and the Emergency Department (n = 7). Clinicians described post-RCL increases in adolescent cannabis use, use of non-combustible modes and high-potency products, and younger age of first use. Clinicians reported social, physical, and policy changes, including changes in social norms, appealing advertisements, marketing, and easier access. Many noted fewer perceived harms among adolescents and greater self-medication post-RCL. They described how RCL contributed to increased parental cannabis use and permissiveness around adolescent use. Finally, many described post-RCL increases in cannabis hyperemesis syndrome, and several noted increased cannabis-related psychosis and acute intoxication, and decreased court-mandated treatment.

CONCLUSIONS

Clinicians from diverse specialties described post-RCL increases in adolescent cannabis use and cannabis-related consequences, alongside changes in social norms, access, marketing and advertisements, and decreased perceptions of harms. Findings can inform strategies to support adolescents in the context of increased cannabis availability and acceptability post-legalization and support the development of hypotheses for broader-scale quantitative work.

Evolution of the substance use landscape: Implications for contingency management

Contingency management (CM), which involves the delivery of incentives upon meeting behavioral goals, has the potential to improve substance use treatment outcomes. The intervention allows for flexibility through numerous modifiable components including changes to incentive magnitude and schedule, target behavior, and intervention structure. Unfortunately, numerous changes in the substance use landscape have occurred in the past 10 to 15 years: Substances are more potent, overdose risk has increased, new substances and methods of use have been introduced, and substance classes are increasingly being intentionally and unintentionally mixed. These developments potentially undermine CM outcomes. We explored recent substance use changes due to legislative, regulatory, social, and economic factors for four substance classes: stimulants, opioids, tobacco, and cannabis. We discuss potential adjustments to the modifiable components of CM for future research in response to these changes. By continually adapting to the shifting substance use landscape, CM can maintain optimal efficacy.

Event-level associations among THC, CBD, social context, and subjective effects during Cannabis use episodes

BACKGROUND

Limited research considers the quantity and potency of cannabis products along with social context on the subjective effects of real-world cannabis use.

AIMS

This study examined the subjective effects of acute use as a function of Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) doses and social context during cannabis use episodes.

METHOD

Ninety-six participants (43.75% male, Mage = 35.73) reporting weekly cannabis use completed a baseline self-report battery assessing cannabis use. Then, THC and CBD potency and quantity of the cannabis product, social context, and subjective experience were assessed through self-initiated surveys after cannabis use episodes during a 14-day ecological momentary assessment (EMA).

RESULTS

Greater feeling high and liking were significantly associated with a higher THC dose than one's average (b = 0.03, p < 0.001; b = 0.02, p < 0.001) and social use (b = 0.38, p < 0.001; b = 0.20, p = 0.01). A higher CBD dose than one's average (b = 0.01, p = 0.04) was significantly associated with greater liking. A significant interaction effect of THC dose and social context (b = 0.01, p = 0.02) was observed such that solitary use had a negative association between THC dose and disliking (b = -0.01, p = 0.04), and social use had a null association (b = 0.003, p = 0.25). Individuals with greater cannabis problems reported lower liking (b = -0.18, p = 0.03) and higher disliking (b = 0.08, p = 0.02), but not feeling high, on average, across the EMA protocol.

CONCLUSION

Social context plays an important role in the subjective experience of cannabis use. Interventions targeting cannabis problems could highlight the evidence that individuals with greater cannabis problems might experience less liking but more disliking in general across use episodes to effectively challenge expectancies/motives of use.

Nicotine use during late adolescence and young adulthood is associated with changes in hippocampal volume and memory performance

Background

With the advent of electronic nicotine delivery systems, the use of nicotine and tobacco products (NTPs) among adolescents and young adults remains high in the US. Use of e-cigarettes additionally elevates the risk of problematic use of other substances like cannabis, which is often co-used with NTPs. However, their effects on brain health, particularly the hippocampus, and cognition during this neurodevelopmental period are poorly understood.

Methods

Healthy late adolescents/young adults (N = 223) ages 16-22 completed a structural MRI to examine right and left hippocampal volumes. Memory was assessed with the NIH Toolbox Picture Sequence Memory Test (PSMT) and Rey Auditory Verbal Learning Test (RAVLT). Cumulative 6-month NTP and cannabis episodes were assessed and modeled continuously on hippocampal volumes. Participants were then grouped based on 6-month NTP use to examine relationships with the hippocampus and memory: current users (CU) endorsed weekly or greater use; light/abstinent users (LU) endorsed less than weekly; and never users (NU).

Results

NTP use predicted larger hippocampal volumes bilaterally while cannabis use had no impact nor interacted with NTP use. For memory, larger left hippocampal volumes were positively associated with PSMT performance, RAVLT total learning, short delay and long delay recall for the NU group. In contrast, there was a negative relationship between hippocampal volumes and performances for LU and CU groups. No differences were detected between NTP-using groups.

Conclusion

These results suggest that the hippocampus is sensitive to NTP exposure during late adolescence/young adulthood and may alter typical hippocampal morphometry in addition to brain-behavior relationships underlying learning and memory processes.

Regulatory Framework for Cannabis: A Position Paper From the American College of Physicians

Cannabis, also known as marijuana, is the dried flowers, stems, seeds, and leaves of the Cannabis sativa plant. It contains more than 100 compounds, including tetrahydrocannabinol, which has psychoactive effects. Federal law prohibits the possession, distribution, and use of cannabis outside limited research activities, but most states have legalized cannabis for medical or recreational use. However, research into the potential therapeutic and adverse health effects of cannabis has been limited, in part because of the drug's federal legal status. In this position paper, the American College of Physicians (ACP) calls for the decriminalization of possession of small amounts of cannabis for personal use and outlines a public health approach to controlling cannabis in jurisdictions where it is legal. ACP recommends the rigorous evaluation of the health effects and potential therapeutic uses of cannabis and cannabinoids as well as research into the effects of legalization on cannabis use. It also calls for evidence-based medical education related to cannabis and increased resources for treatment of cannabis use disorder.

Association of Cannabis Use Disorder With Hospitalizations for Pulmonary Embolism and Subsequent in-Hospital Mortality in Young Adults: A Contemporary Nationwide Analysis

BACKGROUND

With the increase in popularity of cannabis and its use and the lack of large-scale data on cannabis use and venous thromboembolism and pulmonary embolism (PE), we used a nationally representative cohort of young adults (aged 18-44 years) to compare the odds of admissions and in-hospital mortality of PE with and without cannabis use disorder (CUD).

METHODS AND RESULTS

Identified patients with PE using the National Inpatient Sample (2018) were compared for baseline, comorbidities, and outcomes. Multivariable regression analysis, adjusted for covariates, was used to compare the odds of PE in young patients with CUD (CUD+) versus those without (CUD-) and those with prior venous thromboembolism. Propensity score-matched analysis (1:6) was also performed to assess in-hospital outcomes. A total of 61 965 (0.7%) of 8 438 858 young adult admissions in 2018 were PE related, of which 1705 (0.6%) had CUD+. On both unadjusted (odds ratio, 0.80 [95% CI, 0.71-0.90]; P<0.001) and adjusted regression analyses, the CUD+ cohort had a lower risk of PE admission. The CUD+ cohort had fewer routine discharges (58.3% versus 68.3%) and higher transfers to short-term (7.9% versus 4.8%) and nursing/intermediate care (12.6% versus 9.5%) (P<0.001). The PE-CUD+ cohort of in-hospital mortality did not differ from the CUD- cohort. Propensity score-matched (1:6) analysis revealed comparable mortality odds with higher median hospital stay and cost in the CUD+ cohort.

CONCLUSIONS

Young adults with CUD demonstrated lower odds of PE hospitalizations without any association with subsequent in-hospital mortality. The median hospital stay of the CUD+ cohort was longer, they were often transferred to other facilities, and they had a higher cost.

Historical Trends in Cannabis Use Among U.S. Adults Ages 19-55, 2013-2021

OBJECTIVE

The current study used U.S. national data to examine trends in cannabis use from 2013 to 2021, focusing on changes in cannabis prevalence during young and middle adulthood and whether trends differed by sociodemographic characteristics.

METHOD

Data from 2013 to 2021 from 21,182 respondents ages 19-30 and 29,871 ages 35-55 in the national Monitoring the Future panel study (followed since they were in 12th grade in 1976-2020) were used to model historical trends in cannabis prevalence (any 12-month use, any 30-day use, and near-daily use [≥20 occasions in the past 30 days]).

RESULTS

Prevalence of 12-month, 30-day, and near-daily cannabis use significantly increased from 2013 to 2021 for both young and middle adults. Trends for all three behaviors indicated either consistent linear increases or two-slope increases in which the slope estimate was larger in more recent years. Historical increases in 12-month and 30-day use were similar for young and middle adulthood; the historical increase in near-daily use among middle adults had some evidence for a possible pandemic-related deviation. Historical trends did not differ by race/ethnicity or college degree. Trends for 12-month and 30-day use differed by sex, with women increasing more than men over time, especially during middle adulthood.

CONCLUSIONS

Significant increases in the prevalence of cannabis use have occurred over the past decade for young and middle adults across sociodemographic groups, with some indication that near-daily use increased among middle adults at the onset of the pandemic. Although men continue to have a higher prevalence than women, the gap has narrowed, with greater increases in cannabis use among women.

Germany's cannabis act: a catalyst for European drug policy reform?

With the enforcement of the Cannabis Act on 1 April 2024, Germany has adopted one of the most liberal legal approaches to cannabis on the continent. The German model prioritises a non-profit approach and precludes legal market mechanisms. We believe these are the main drivers for increasing cannabis use and related health problems, based on observations following cannabis legalisation in Canada and many states in the U.S. Although legalising cannabis possession and cultivation may not immediately eliminate the illegal market, it is expected to serve public health goals. Despite the overall positive evaluation of the Cannabis Act in Germany, there are three potential areas of concern: the potential for misuse of the medical system, the normalization of cannabis use, and the influence of the cannabis industry. The German model may herald the beginning of a new generation of European cannabis policies, but concerted efforts will be required to ensure that these policy reforms serve rather than undermine public health goals.

Adult use cannabis legalization and cannabis use disorder treatment in California, 2010-2021

INTRODUCTION

Many nations and jurisdictions have legalized non-medical adult use of cannabis, or are considering doing so. This paper contributes to knowledge of adult use legalization's associations with cannabis use disorder (CUD) treatment utilization.

METHODS

This study collected data from a dataset of all publicly funded substance use disorder treatment delivered in California from 2010 to 2021 (1,460,066 episodes). A logistic regression model estimates adult use legalization's impacts on CUD treatment utilization using an individual-level pre-post time series model, including individual and county-level characteristics and county and year-fixed effects.

RESULTS

Adult use legalization was associated with a significant decrease in the probability of admission to CUD treatment (average marginal effect (AME): -0.005, 95 % CI: -0.009, 0.000). Adult use legalization was also associated with a decrease in the probability of admission to CUD treatment for males (AME: -0.025, 95 % CI: -0.027, -0.023) Medi-Cal beneficiaries (AME: -0.025, 95 % CI: -0.027, -0.023) adults ages 21+ (AME: -0.011, 95 % CI: -0.014, -0.009) and Whites (AME: -0.012, 95 % CI: -0.015, -0.010), and an increase in the probability of admission to CUD treatment for patients referred from the criminal justice system (AME: 0.017, 95 % CI: 0.015, 0.020) and Blacks (AME: 0.004, 95 % CI: 0.000, 0.007) and Hispanics (AME: 0.009, 95 % CI: 0.006, 0.011).

CONCLUSIONS

Adult use legalization is associated with declining CUD treatment admissions, even though cannabis-related problems are becoming more prevalent. Policies and practices that protect public health, and engage people with CUD in treatment are needed.

Measuring Cannabis Reinforcement among Young Adults: A Mixed Methods Examination

Introduction

Increasing reinforcement received from cannabis-free activities, relative to reinforcement from cannabis-related activities, is one way to reduce harmful cannabis use. Thus, accurate measurement of cannabis reinforcement is important. Using convergent mixed methods, we developed the Adolescent Reinforcement Survey Schedule-Cannabis Use Version (ARSS-CUV). ARSS-CUV, adapted from the alcohol use version, measures cannabis reinforcement by asking individuals how frequently they engaged in, and how much they enjoyed, different activities when using and not using cannabis.

Method

Young adults (N = 65; M age = 20.4 years [SD = 1.8]) completed measures of cannabis use, the ARSS-CUV, and provided feedback on included activities, via focus groups. Following Standards for Educational and Psychological Testing framework, this study examined evidence of measurement validity based on item content.

Results

Quantitative findings revealed that peer interactions were the most reinforcing activities, whereas activities related to family were least reinforcing. Qualitative findings indicated some confusion with question wording. Participants also indicated the importance of environmental context when using cannabis and noted who they use cannabis with may be more important than the activity they are doing. Changes were made to survey flow and response choices after participant feedback.

Conclusions

ARSS-CUV includes revisions in activities solicited and response format. The revised ARSS-CUV provides opportunities to advance measurement of an important construct (i.e., reinforcement) in the study of cannabis use. Psychometric properties of the ARSS-CUV across different populations and contexts of use (e.g., polysubstance use) should be examined.

Adolescent-onset cannabis use and parenting young children: an investigation of differential effectiveness of a digital parenting intervention

Introduction

There is scant empirical work on associations between current and past cannabis use and parenting skills in parents of young children. As recreational cannabis use is now legal in nearly half of states in the U.S., cannabis use is becoming more ubiquitous.

Methods

In the current study, parents of toddler and pre-school age children were randomly assigned to participate in an app-based parenting skills program that included telehealth coaching (Family Check-Up Online; FCU-O), with a focus on parenting in the context of substance use. We aimed to test associations between adolescent-onset and current cannabis use and parent mental health and parenting skills, as well as whether effects of the FCU-O on parent mental health outcomes varied as a function of past cannabis use. Participants were 356 parents of children ages 1.5-5 participating in a randomized controlled trial of the FCU-O. Parents screened into the study if they reported current or past substance misuse or current depressive symptoms. After completing a baseline assessment, parents were randomly assigned to the FCU-O or control group and completed a follow-up assessment 3 months later. Parents retrospectively reported on the age when they initially used substances, as well as their current use.

Results

After accounting for current cannabis use, adolescent-onset cannabis use was significantly associated with higher symptoms of anxiety and depression, but not with parenting skills. Adolescent-onset cannabis use was found to significantly moderate the effect of the FCU-O on parents' anxiety symptoms. Specifically, the FCU-O was particularly effective in reducing anxiety symptoms for parents with adolescent-onset regular cannabis use, after accounting for current cannabis use.

Discussion

Adolescent-onset regular cannabis use may be a risk factor for later mental health challenges in parents of children under 5. An app-based parenting intervention may be particularly helpful in reducing symptoms of anxiety for parents who used cannabis regularly as adolescents. The findings have significant implications for the prevention of multigenerational risk for substance use and mental health challenges.

Testing a Brief Quitline Intervention for Tobacco Cannabis Co-Users: A Randomized Controlled Pilot Study

Background: Tobacco cannabis co-use is common and becoming more prevalent. Frequent and heavy users of cannabis may struggle to quit smoking. Quitlines offer free cessation treatment in the United States and 25% of quitline callers may also be cannabis users. The present paper describes a randomized pilot study of a tailored intervention for cannabis and cigarette co-users. The intervention combines the quitline smoking cessation treatment with a motivational enhancement therapy-based cannabis intervention. Methods: The randomized pilot study was conducted within four state-funded quitlines with quitline coaches as interventionists. 102 quitline callers who were cannabis and cigarette co-users were randomized to receive treatment as usual (TAU) or the new Quitline Check-Up (QLCU) intervention. Outcomes were collected 90 days post-randomization. Primary outcomes included feasibility and acceptability of delivering the QLCU in the quitline setting. Secondary outcomes included 7-day point prevalence tobacco abstinence, past 30-day cannabis use, and Cannabis Use Disorder Identification Test scores. Results: Study participants were heavy cannabis users, averaging 25 days of use in the past 30; nearly 70% used at a level considered hazardous. Fidelity ratings indicated coaches were successful at delivering the intervention. Treatment engagement was high for both groups (TAU m = 3.4 calls; QLCU m = 3.6 calls) as was treatment satisfaction. Intent-to-treat quit rates (with survey non-responders classified as smokers) were 28.6% for the TAU control group and 24.5% for the QLCU group (P = .45). Discussion: Hazardous cannabis use rates were high in this sample of tobacco cannabis co-users calling quitlines to quit smoking. The intervention for co-users was acceptable and feasible to deliver. No improvements in tobacco cessation outcomes were observed. Pragmatic intervention development within a real-world clinical setting can streamline the intervention development process. More research is needed on tobacco cannabis co-users and who can benefit from a tailored intervention. Registered: ClinicalTrials.gov NCT04737772, February 4, 2021.

Evolving Disparities in Cannabis Use Among Youth by Demographics and Tobacco and Alcohol Use in the U.S.: 2013-2021

INTRODUCTION

This study investigated the prevalence of past 30-day cannabis use among U.S. youth by cigarette use, alcohol use, demographics, and state-of-residence cannabis legal status in 2021 and examined whether changes in cannabis use prevalence were modified by these factors from 2013 to 2021.

METHODS

Data were drawn from the 24 states that collected cannabis use data participating in the Youth Risk Behavior Surveillance System from 2013 to 2021. Logistic regression analyses estimated past 30-day cannabis prevalence in 2021 and produced AORs by current cigarette, alcohol, and state-of-residence cannabis legal status. The same method was used with year as the exposure, adjusting for sex, race, and ethnicity, to assess trends in prevalence from 2013 to 2021.

RESULTS

In 2021, cannabis use was more common among female youth (16.75% vs 13.83% [AOR=1.26, 95% CI=1.16, 1.37]) and non-Hispanic Black and Hispanic youth than among non-Hispanic White youth (17.19%, 16.14% vs 14.60% [AOR=1.25, 95% CI=1.12, 1.39 and AOR=1.16, 95% CI=1.04, 1.29, respectively]). Cannabis use was much more common among youth who reported any past 30-day cigarette or alcohol use (44.90% vs 6.48% [AOR=11.80, 95% CI=10.57, 13.18]). Declines in cannabis use were observed independent of state-level cannabis law from 2013 to 2021, and cannabis use prevalence did not differ significantly by state-of-residence cannabis legal status among the 24 participating states in 2021.

CONCLUSIONS

Public health officials should carefully consider the potential impact of expanding commercialization of cannabis as a wellness product on youth cannabis use, especially with regard to minoritized populations and co-use with tobacco and alcohol. National and state-level public health education on cannabis use and youth-oriented prevention of cannabis uptake are long overdue.

Cannabis use disorder and perioperative outcomes following complex cancer surgery

INTRODUCTION

Cannabis usage is increasing in the United States, especially among patients with cancer. We sought to evaluate whether cannabis use disorder (CUD) was associated with higher morbidity and mortality among patients undergoing complex cancer surgery.

METHODS

Patients who underwent complex cancer surgery between January 2016 and December 2019 were identified in the National Inpatient Sample database. CUD was defined according to ICD-10 codes. Propensity score matching was performed to create a 1:1 matched cohort that was well balanced with respect to covariates, which included patient comorbidities, sociodemographic factors, and procedure type. The primary composite outcome was in-hospital mortality and seven major perioperative complications (myocardial ischemia, acute kidney injury, stroke, respiratory failure, venous thromboembolism, hospital-acquired infection, and surgical procedure-related complications).

RESULTS

Among 15 014 patients who underwent a high-risk surgical procedure, a cohort of 7507 patients with CUD (median age; 43 years [IQR: 30-56 years]; n = 3078 [41.0%] female) were matched with 7507 patients who were not cannabis users (median age; 44 years [IQR: 30-58 years); n = 2997 [39.9%] female). CUD was associated with slight increased risk relative to postoperative kidney injury (CUD, 7.8% vs. no CUD, 6.1%); however, in-hospital mortality was slightly lower (CUD, 0.9% vs. no CUD, 1.6%) (both p < 0.001). On multivariable analysis, after controlling for other risk factors, CUD was not associated with higher morbidity and mortality (adjusted odds ratio: 1.06, 95% CI: 0.98-1.15; p = 0.158).

CONCLUSION

CUD was not associated with a higher risk of postoperative morbidity and mortality following complex cancer surgery.

The Puzzle of Marijuana Use and Forced Vital Capacity

In study after study, marijuana use has been found to be associated with increased forced vital capacity (FVC). This is puzzling, because marijuana is commonly consumed by inhalation of its smoke, and smoke exposure of any kind is not generally considered a cause of increased FVC. Although this observation was first made decades ago, a satisfactory explanation remains elusive. In this review we survey the evidence supporting the relationship between marijuana use and increased FVC, discuss potential threats to validity when inferring causation, and, presupposing a possible causal relationship, pose two key questions. First, what are possible physiologic or pathophysiologic mechanisms by which marijuana use might increase FVC? Second, why might this effect be consistently observed with marijuana use but not with tobacco use? Explanations for the first question include lung and chest growth and remodeling from strenuous marijuana smoke inhalation and reductions in lung elastic recoil from marijuana smoke exposure. Explanations for the second include differences between marijuana and tobacco in smoke composition and patterns of consumption, such as smoking topography. Finally, the possibility that smoke, whether from marijuana or tobacco, might have nonmonotonic effects on FVC depending on the degree of exposure is explored. In synthesizing a curated breadth of epidemiologic and physiologic science, we leverage a perplexing observation to generate potential insights and avenues for further research into the biological effects of smoke, from marijuana or otherwise, on the respiratory system.

Cannabinoid hyperemesis syndrome: Clinical trajectories and patterns of use three months following a visit to the emergency department

OBJECTIVES

Cannabinoid hyperemesis syndrome (CHS) is a clinical condition of cyclic vomiting, nausea, and abdominal pain associated with chronic cannabis use. Despite increased recognition of CHS, there are limited details on cannabis use practices and symptoms over time. Understanding what happens in the period surrounding the emergency department (ED) visit, including any changes in symptoms and cannabis use practices following the visit, can help inform the development of patient-centered interventions around cannabis use disorder for patients with CHS.

METHODS

A prospective observational cohort (n = 39) of patients with suspected CHS recruited from the ED at the time of a symptomatic cyclic vomiting episode was followed for 3 months. Disease progression, cannabis use practices, and health care utilization were monitored.

RESULTS

Participants reported high rates of persistent CHS symptoms (abdominal pain, nausea, or cyclic vomiting) in the 2-week period immediately following an ED visit with a median duration of 7 days. Cannabis use frequency and quantity were reduced immediately after the ED visit, but most participants returned to pre-ED visit cannabis use patterns within a few days. Recurrent ED visits for cyclic vomiting were reported by 25% of participants who completed follow-up during the 3-month follow-up period.

CONCLUSIONS

Participants continued to have ongoing symptoms after the ED visit, but most managed symptoms on their own and did not return to the ED. Longitudinal studies beyond 3 months are needed to better understand the clinical course of patients with suspected CHS.

Where Do Adults in the United States Obtain Cannabis? A Nationally Representative Study Examining the Relationships Between Sociodemographic Factors, Cannabis Use Characteristics and Sources of Cannabis

OBJECTIVE

Characterization of population subgroups based on where they acquire cannabis is unexplored. We examine relationships between sociodemographic characteristics, cannabis use modality, risky cannabis use, and source of cannabis.

METHOD

Analyzing a representative sample (unweighted n = 8,089) of U.S. adults living in medical cannabis-permitting states with past-year cannabis use from the 2021 National Survey on Drug Use and Health, we determined source of last cannabis used. Outcome groups were purchased from a dispensary, purchased from another source, or nonpurchased source. Incorporating the complex survey design, descriptive statistics and adjusted multinomial logistic regressions evaluated associations between sociodemographic, individual cannabis use characteristics, and source of cannabis. Secondary analyses described cannabis purchasing characteristics among the subsample who last purchased cannabis.

RESULTS

Purchasing from a dispensary was the most common source of cannabis (42.5%). Significant relationships between sociodemographic characteristics, cannabis use modality, risky cannabis use, and source of cannabis were found. Recent cannabis initiates and those with cannabis vaporizer use had an increased likelihood of purchasing cannabis from a dispensary. Purchasing from a nondispensary source was most likely among those with daily cannabis use, past-month blunt use, past-year driving under the influence, cannabis use disorder, and cannabis and alcohol co-use. Among those purchasing cannabis, joints and other forms of cannabis were more likely to be purchased from a dispensary than purchased from other sources.

CONCLUSIONS

We identified key sociodemographic and cannabis use characteristics that may influence where individuals obtain cannabis, which are important for cannabis behavior surveillance and cannabis use prevention and intervention strategies to consider.

Association of mental health related quality of life and other factors with treatment seeking for substance use disorders: A comparison of SUDs rooted in legal, partially legal, and illegal substances

The association of subjective mental health-related quality of life (MHRQOL) and treatment use among people experiencing common substance use disorders (SUDs) is not known. Furthermore, the association of a given substance's legal status with treatment use has not been studied. This work aims determine the association of MHRQOL with SUD treatment use, and how substance legal status modulates this relationship. Our analysis used nationally-representative data from the NESARC-III database of those experiencing past-year SUDs (n = 5,808) to compare rates of treatment use and its correlates among three groups: those with illicit substance use disorders (ISUDs); those with partially legal substance use disorders, i.e., cannabis use disorder (CUD); and those with fully legal substance use disorders, i.e., alcohol use disorder (AUD). Survey-weighted multiple regression analysis was used to assess the association of MHRQOL with likelihood of treatment use among these three groups, both unadjusted and adjusted for sociodemographic, behavioral, and diagnostic factors. Adults with past-year ISUDs were significantly more likely to use treatment than those with CUD and AUD. Among those with ISUDs, MHRQOL had no significant association with likelihood of treatment use. Those with past-year CUD saw significant negative association of MHRQOL with treatment use in unadjusted analysis, but not after controlling for diagnostic and other behavioral health factors. Those with past-year AUD had significant negative association of MHRQOL with treatment use in both unadjusted and adjusted analysis. If legalization and decriminalization continue, there may be a greater need for effective public education and harm reduction services to address this changing SUD landscape.

Nicotine and Alcohol Use as Predictors of Recreational Cannabis Use in Adolescence: A Systematic Review and Narrative Synthesis

Background: The prevalence of recreational cannabis use among adolescents is a growing public health concern due to its link to short- and long-term adverse effects on adolescents' wellbeing, physical health, mental health, and interpersonal behaviors. Method: Five databases were searched from inception to March 17, 2023, for exposure (nicotine product, alcohol) and outcome (recreational cannabis) in adolescents (persons aged 10-19 years). The studies were screened independently by two reviewers, and the quality of the studies was assessed with Newcastle Ottawa and AXIS tool. PRISMA guidelines were employed in this review. Result: Twenty-one (21) studies involving 2,778,406 adolescents were included in the appraisal and heterogeneity was found among these studies. Ascertainment bias was commonly detected in thirteen (13) of the included studies. Among the substances examined as potential exposures, nicotine-product use emerged as a significant factor associated with future cannabis use among adolescents, particularly in mid-adolescence and in places where recreational cannabis use has been legalized. Conclusion: Current evidence suggests an association between nicotine-product use and subsequent recreational cannabis use among adolescents. However, further research is needed to establish causality between exposure to nicotine substances and the use of recreational cannabis within this age demographic. Additionally, there is a need for the development of prevention programs and targeted policies that continuously inform and update this vulnerable sub-population about the risks associated with cannabis use for leisure.

State cannabis laws and cannabis positivity among fatally injured drivers

BACKGROUND

As of November 8, 2023, 24 states and the District of Columbia have legalized cannabis for both recreational and medical use (RMCL-states), 14 states have legalized cannabis for medical use only (MCL-states) and 12 states have no comprehensive cannabis legislation (NoCL-states). As more states legalize cannabis for recreational use, it is critical to understand the impact of such policies on driving safety.

METHODS

Using the 2019 and 2020 Fatality Analysis Reporting System data, we performed multivariable logistic regression modeling to explore the association between state level legalization status and cannabis positivity using toxicological testing data for 14,079 fatally injured drivers. We performed a sensitivity analysis by including multiply imputed toxicological testing data for the 14,876 eligible drivers with missing toxicological testing data.

RESULTS

Overall, 4702 (33.4%) of the 14,079 fatally injured drivers tested positive for cannabis use. The prevalence of cannabis positivity was 30.7% in NoCL-states, 32.8% in MCL-states, and 38.2% in RMCL-states (p < 0.001). Compared to drivers fatally injured in NoCL-states, the adjusted odds ratios of testing positive for cannabis were 1.09 (95% confidence interval: 0.99, 1.19) for those fatally injured in MCL-states and 1.54 (95% confidence interval: 1.34, 1.77) for those fatally injured in RMCL-states. Sensitivity analysis yielded similar results.

CONCLUSIONS

Over one-third of fatally injured drivers tested positive for cannabis use. Drivers fatally injured in states with laws permitting recreational use of cannabis were significantly more likely to test positive for cannabis use than those in states without such laws. State medical cannabis laws had little impact on the odds of cannabis positivity among fatally injured drivers.

Perception of pregnant individuals, health providers and decision makers on interventions to cease substance consumption during pregnancy: a qualitative study

BACKGROUND

Despite multiple recommendations and strategies implemented at a national and international level, cigarette smoking, alcohol consumption, and cannabis use during pregnancy remains high in most countries. The objective of this study was to examine key stakeholders' perception of the treatment interventions adopted in Spain, to identify political, organizational and personal factors associated with successful implementation, and to propose strategies for improvement.

METHODS

A qualitative study with a phenomenological approach was conducted in 2022. The target groups were: (1) clinical decision makers in the field of addiction science, (2) health professionals who carry out treatment interventions, and (3) pregnant individuals who use tobacco, alcohol or cannabis. Two focus groups and eight in-depth interviews were conducted, recorded, and transcribed. Exploratory analysis and inductive open coding was performed, codes were merged into categories, and subcategories were identified.

RESULTS

The analysis resulted in 10 subcategories which were further merged into three main categories: (1) Degree of adoption and utility of treatment interventions implemented; (2) Needs and demands with respect to the organization of treatment interventions; and, (3) Personal barriers to and facilitators for treatment. Respondents reported that despite multiple national and regional cessation initiatives, treatment interventions were rarely adopted in clinical practice. Health care administrators demanded reliable records to quantify substance use for better planning of activities. Health care professionals advocated for additional time and training and both echoed the importance of integrating cessation interventions into routine prenatal care and creating in-house specialized units. The difficulty in quitting, lack of awareness of risk for foetus and child and the controversial advice were identified as barriers by pregnant individuals.

CONCLUSIONS

Consistent with previous work, this study found that cessation strategies implemented by the health authorities are not effective if they are not accompanied by organizational and behavioral changes. The current study identifies a set of factors that could be pivotal in ensuring the success of treatment interventions targeting tobacco, alcohol and cannabis use among pregnant individuals.

Results of a randomized controlled trial of the cannabis eCHECKUP TO GO personalized normative feedback intervention on reducing cannabis use, cannabis consequences, and descriptive norms

BACKGROUND

The prevalence of cannabis use disorder and its negative consequences among young adults has highlighted the need for prevention and early intervention programs. However, low treatment prevalence persists due to factors such as lack of perceived need, concerns about stigma, and limited access to treatment. To address these barriers, web-based cannabis interventions have been developed, but their efficacy remain limited. This study aims to evaluate the cross-site efficacy of the Cannabis eCHECKUP TO GO program, a web-based Personalized Normative Feedback and Protective Behavioral Strategies intervention for reducing cannabis use frequency and consequences in college students with willingness to change.

METHODS

Participants were 781 students from three universities (two in Canada, one in the US) who reported using cannabis in the past month and expressed interest in reducing or engaging in safer cannabis use. The study randomly assigned them to either an experimental group that received personalized normative feedback or a control group that received information on healthy stress management. The study collected follow-up data 4 weeks after the initial intervention and measured participants' frequency of cannabis use, number of cannabis consequences, descriptive and injunctive norms at both time points.

RESULTS

The results showed no significant reductions in cannabis use or negative consequences of use. However, students who received personalized normative feedback experienced a significant reduction in descriptive norms related to cannabis use, to be more in line with actual use.

CONCLUSION

This study suggests that more targeted interventions may be necessary for university students who are already using and seeking help to reduce their use.

Disposable E-Cigarette Use and Subsequent Use Patterns in Adolescents and Young Adults

BACKGROUND AND OBJECTIVES

Disposable electronic cigarettes (e-cigarettes) are widely used by adolescents and young adults (AYAs). Whether using disposable devices is associated with future e-cigarette use patterns is unknown but important for informing e-cigarette regulation.

METHODS

Prospective longitudinal study combining data from adolescent (14-17 years) and young adult (21-24 years) cohorts from Southern California surveyed at baseline and approximately 8-month follow-up during 2021 to 2022. The analyses included AYAs who used e-cigarettes in the past 30 days at baseline and had exposure and outcome data (N = 403; adolescent n = 124, young adult n = 279).

RESULTS

In the pooled sample of AYAs who used e-cigarettes at baseline (57.2% cis-gender female, 56.2% Hispanic), 278 (69.0%) reported past 30-day disposable e-cigarette use, and 125 (31.0%) used only nondisposable e-cigarettes. Baseline use of disposable (versus only nondisposable) devices was associated with higher odds of continued e-cigarette use (adjusted odds ratio = 1.92; 95% confidence interval = 1.09-3.42) and a greater number of times used e-cigarettes per day at follow-up (adjusted incidence rate ratio = 1.29; 95% confidence interval = 1.02-1.63). In supplemental analyses, disposable e-cigarette use was associated with greater odds of no changes (versus reductions) in e-cigarette use frequency and puffs per episode from baseline to follow-up but was not associated with increases in use frequency and intensity. No differences in e-cigarette use outcomes were found between those with poly-device (disposable and nondisposable) versus only disposable device use.

CONCLUSIONS

Use of disposable e-cigarette devices among AYAs may be associated with higher risks for persistent e-cigarette use patterns, which should be considered in tobacco product regulation designed to protect AYAs.

Associations between cannabis policies and state-level specialty cannabis use disorder treatment in the United States, 2004-2019

BACKGROUND

Cannabis use disorder (CUD) treatment prevalence decreased in the US between 2002 and 2019, yet structural mechanisms for this decrease are poorly understood. We tested associations between cannabis laws becoming effective and self-reported CUD treatment.

METHODS

Restricted-use 2004-2019 National Surveys on Drug Use and Health included people ages 12+ classified as needing CUD treatment (i.e., past-year DSM-5-proxy CUD or last/current specialty treatment for cannabis). Time-varying indicators of medical cannabis laws (MCL) with/without cannabis dispensary provisions differentiated state-years before/after laws using effective dates. Multi-level logistic regressions with random state intercepts estimated individual- and state-adjusted CUD treatment odds by MCLs and model-based changes in specialty CUD treatment state-level prevalence. Secondary analyses tested associations between CUD treatment and MCL or recreational cannabis laws (RCL).

RESULTS

Using a broad treatment need sample definition in 2004-2014, specialty CUD treatment prevalence decreased by 1.35 (95 % CI = -2.51, -0.18) points after MCL without dispensaries and by 2.15 points (95 % CI = -3.29, -1.00) after MCL with dispensaries provisions became effective, compared to before MCL. Among people with CUD in 2004-2014, specialty treatment decreased only in MCL states with dispensary provisions (aPD = -0.91, 95 % CI = -1.68, -0.13). MCL were not associated with CUD treatment use in 2015-2019. RCL were associated with lower CUD treatment among people classified as needing CUD treatment, but not among people with past-year CUD.

CONCLUSIONS

Policy-related reductions in specialty CUD treatment were concentrated in states with cannabis dispensary provisions in 2004-2014, but not 2015-2019, and partly driven by reductions among people without past-year CUD. Other mechanisms (e.g., CUD symptom identification, criminal-legal referrals) could contribute to decreasing treatment trends.

Systematic Review and Meta-Analysis: Medical and Recreational Cannabis Legalization and Cannabis Use Among Youth in the United States

OBJECTIVE

Dramatic changes in state-level cannabis laws (CL) over the past 25 years have shifted societal beliefs throughout the United States, with unknown implications for youth. In the present study, we conducted an updated systematic review and meta-analysis examining estimated effects of medical cannabis legalization (MCL) and recreational cannabis legalization (RCL) on past-month cannabis use among US youth.

METHOD

A systematic review was conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, followed by a subsequent meta-analysis investigating the associations between state-level cannabis laws (ie, MCL vs non-MCL, and RCL vs non-RCL) and past-month cannabis use prevalence among US adolescents and young adults. Supplemental analyses examined age-group effects and design-related factors.

RESULTS

Our search identified 4,604 citations, 34 and 30 of which were included in qualitative and quantitative analyses, respectively. Meta-analysis of MCL studies identified no significant association between MCL and change in past-month youth cannabis use (odds ratio [OR] = 0.981, 95% CI = 0.960, 1.003). Meta-analysis of RCL studies showed significantly increased odds of past-month cannabis use (OR = 1.134, 95% CI = 1.116-1.153). Meta-analysis of more recent studies, however, showed a significantly increased odds of past-month cannabis use among both adolescents and young adults (OR = 1.089, 95% CI = 1.015,1.169, and OR = 1.221, 95% CI = 1.188,1.255, respectively).

CONCLUSION

Cannabis legalization has complex and heterogenous effects on youth use that may differ across law types. Our meta-analytic results showed modest positive effects of RCL on past-month cannabis use (more so in young adults than in adolescents) and minimal effects of MCL on these outcomes in US youth. Given the shift toward recreational legalization, additional focus on RCL effects is warranted.

Medicinal cannabis use among young adults during California's transition from legalized medical use to adult-use: a longitudinal analysis

Background: In 2016, California transitioned from legalized medical cannabis use to adult-use. Little is known about how this policy change affected medicinal cannabis use among young adults.Objectives: To identify longitudinal groups of medicinal cannabis users and concurrent changes in health- and cannabis use-related characteristics among young adults in Los Angeles between 2014 and 2021.Methods: Cannabis users (210 patients and 156 non-patients; 34% female; ages 18-26 at baseline) were surveyed annually across six waves. Longitudinal latent class analysis derived groups from two factors - cannabis patient status and self-reported medicinal use. Trajectories of health symptoms, cannabis use motives, and cannabis use (daily/near daily use, concentrate use, and problematic use) were estimated across groups.Results: Three longitudinal latent classes emerged: Recreational Users (39.3%) - low self-reported medicinal use and low-to-decreasing patient status; Recreational Patients (40.4%) - low self-reported medicinal use and high-to-decreasing patient status; Medicinal Patients (20.3%) - high self-reported medicinal use and high-to-decreasing patient status. At baseline, Medicinal Patients had higher levels of physical health symptoms and motives than recreational groups (p < .05); both patient groups reported higher level of daily/near daily and concentrate use (p < .01). Over time, mental health symptoms increased in recreational groups (p < .05) and problematic cannabis use increased among Recreational Patients (p < .01).Conclusions: During the transition to legalized adult-use, patterns of medicinal cannabis use varied among young adults. Clinicians should monitor increases in mental health symptoms and cannabis-related problems among young adults who report recreational - but not medicinal - cannabis use.

Is legalization of recreational cannabis associated with levels of use and cannabis use disorder among youth in the United States? A rapid systematic review

Cannabis legalization policies are rapidly changing in the United States. While there are concerns that recreational legalization will negatively affect young people, previous reviews have not provided clear indication of such effects. The purpose of this rapid systematic review was to examine whether recreational legalization was associated with increases in prevalence of cannabis use and use disorder among adolescents and young adults. PubMed/MEDLINE, Embase, Scopus, PsycInfo, Web of Science, Dissertations & Theses Global, the Trip Database, and OpenGrey were searched from date of inception through Marcy 17, 2022 to retrieve all relevant records. English language and human subject filters were applied. Two reviewers screened abstracts and titles, assessed full text articles, and coded the final included articles. Studies including primarily 10- to 19-year-olds were classified as adolescent, and those between 18 and 26 years as young adult. Our search identified 33 research reports (22 with adolescent samples; 14 young adult). For adolescents, ten studies reported no change in use prevalence associated with legalization, six reported a decrease, and seven reported an increase. Among young adults, most studies (8) showed an increase in at least one prevalence measure, four showed no change, and one showed a decrease. Only two adolescent and one young adult study examined cannabis use disorder, both adolescent studies showed an increase, and the young adult showed no change. The majority of studies had risk of bias. Recreational legalization may be associated with increases in prevalence of cannabis use in young adults while results for adolescents are mixed. Policymakers and practitioners should consider appropriate prevention and treatment options for young people.Trial Registration: PROSPERO #CRD42021276984.

Association Between Marijuana Laws and Suicide Among 12- to 25-Year-Olds in the United States From 2000 to 2019

OBJECTIVE

Cannabis use is associated with suicide-related outcomes in both adolescents and adults, and may be increasing amid shifting cannabis policies. However, little is known about the impact of medical marijuana legalization (MML) and recreational marijuana legalization (RML) policies on youth suicide. Using 20 years of national data, we examined associations between MML, RML, and suicide-related mortality among US individuals aged 12 to 25 years, and assessed whether they varied based on age and sex.

METHOD

Suicide deaths (N = 113,512) from the 2000-2019 National Vital Statistics System Multiple Cause of Death files for age groups 12 to 13, 14 to 16, 17 to 19, 20 to 22, and 23 to 25 years were examined in relation to time-varying cannabis law status using a staggered adoption difference-in-difference (DiD) approach with a negative binomial regression to determine associations between MML, RML, and suicide rates, controlling for individual- and state-level covariates and accounting for the varying effective dates of MML and RML by state.

RESULTS

The overall unadjusted annual suicide rate was 10.93/100,000, varying from 9.76 (states without marijuana laws (ML)) to 12.78 (MML states) to 16.68 (RML states). In multivariable analysis, both MML (incidence rate ratio [IRR] = 1.10, 95% CI: 1.05-1.15) and RML (IRR = 1.16, 95% CI: 1.06-1.27) were associated with higher suicide rates among female youth compared to those in states without ML. Youth aged 14 to 16 years had higher rates of suicide in states with RML compared to states with MML (IRR = 1.14, 95% CI: 1.00-1.30) and states without ML (IRR = 1.09, 95% CI: 1.00-1.20). Findings were consistent across sensitivity analyses.

CONCLUSION

MML and RML were associated with increased suicide-related mortality in female youth and 14- to- 16-year-old individuals of both sexes. Mechanisms through which cannabis policies are related to increased youth suicide warrant further study and should inform legislative reform.

Using publicly available data to predict recreational cannabis legalization at the county-level: A machine learning approach

BACKGROUND

There is substantial geographic variability in local cannabis policies within states that have legalized recreational cannabis. This study develops an interpretable machine learning model that uses county-level population demographics, sociopolitical factors, and estimates of substance use and mental illness prevalences to predict the legality of recreational cannabis sales within each U.S. county.

METHODS

We merged data and selected 14 model inputs from the 2010 Census, 2012 County Presidential Data from the MIT Elections Lab, and Small Area Estimates from the National Surveys on Drug Use and Health (NSDUH) from 2010 to 2012 at the county level. County policies were labeled as having recreational cannabis legal (RCL) if the sale of recreational cannabis was allowed anywhere in the county in 2014, resulting in 92 RCL and 3002 non-RCL counties. We used synthetic data augmentation and minority oversampling techniques to build an ensemble of 1000 logistic regressions on random sub-samples of the data, withholding one state at a time and building models from all remaining states. Performance was evaluated by comparing the predicted policy conditions with the actual outcomes in 2014.

RESULTS

When compared to the actual RCL policies in 2014, the ensemble estimated predictions of counties transitioning to RCL had a macro f1 average score of 0.61. The main factors associated with legalizing county-level recreational cannabis sales were the prevalences of past-month cannabis use and past-year cocaine use.

CONCLUSION

By leveraging publicly available data from 2010 to 2012, our model was able to achieve appreciable discrimination in predicting counties with legal recreational cannabis sales in 2014, however, there is room for improvement. Having demonstrated model performance in the first handful of states to legalize cannabis, additional testing with more recent data using time to event models is warranted.

Associations between simultaneous use of alcohol and cannabis and cannabis-related problems in 2014-2016: evidence from the Washington panel survey

BACKGROUND

To address the research question of how simultaneous users of alcohol and cannabis differ from concurrent users in risk of cannabis use problems after the recreational marijuana legalization in Washington State.

METHODS

We used generalized estimating equations with a Poisson distribution to analyze the association between simultaneous use of alcohol and marijuana (SAM) and cannabis-related problems compared to concurrent use. The data is a longitudinal sample of drinkers and cannabis users (n = 257, 47% female) aged 18 years and older from Washington State in 2014-2016. We adjusted for survey weights to account for differential probability of selection and response rates. The primary outcome is the past-six-month CUDIT problem subscale (ranging from 0 to 28), which is the total score for seven CUDIT problem items, after excluding the three items that covered marijuana use frequency. Covariates include marijuana use frequency (daily/near daily use, regular use, or infrequent use), marijuana daily quantity, alcohol daily volume, panel survey cycle, medical marijuana recommendation, driving time to nearest marijuana outlet, age of marijuana use onset, and other demographics.

RESULTS

After adjusting for covariates, we found that compared to concurrent use, SAM was significantly positively associated with CUDIT problem subscale (IRR = 1.68, 95% CI: 1.25-2.27, p < 0.001); daily/near daily use of marijuana was strongly significantly associated with CUDIT problem subscale compared with infrequent use (IRR = 5.1, 2.71-9.57, p < 0.001) or regular use (IRR = 3.05, 1.91-4.85, p < 0.001). Secondary analyses using CUDIT total score as the outcome also showed a significant positive association with SAM compared to concurrent use (IRR = 1.17, 1.02-1.34, p < 0.05).

CONCLUSIONS

This study highlighted the importance of SAM, in addition to cannabis use frequency for predicting cannabis-related problems.

Young Adult Depression and Cannabis Use: Associations Before and After Recreational Legalization

INTRODUCTION

The co-occurrence of depression with cannabis use worsens both mood and substance use disorder outcomes, with young adults particularly at risk of co-occurrence. This research investigates whether the association of state-level prevalence rates of young adult (age 18-25) depression and cannabis use in the U.S. changed following enactment of recreational (adult use) cannabis legalization between 2008 and 2019.

METHODS

Annual, state prevalence data on past-year major depressive episode (hereafter, depression) and past-month cannabis use were extracted from the National Survey on Drug Use and Health (N=600 state-year observations). Moderated regression models tested whether the association of depression with cannabis use differed before versus after recreational legalization by comparing prevalence rates of depression and cannabis use in states that enacted recreational legalization to those that did not, while fixing state, year, and medical legalization effects. Data were accessed and analyzed in 2023.

RESULTS

Prevalence rates of both depression and cannabis use increased throughout the study period. The positive statistical effect of depression on cannabis use more than doubled in magnitude after legalization (β=0.564, 95% CI=0.291, 0.838) as compared to before (β=0.229, 95% CI=0.049, 0.409), representing a significant change (β=0.335, 95% CI=0.093, 0.577).

CONCLUSIONS

These results suggest that the association between prevalence rates of young adult depression and cannabis use strengthened following recreational legalization in the U.S. This is potentially due to increases in cannabis accessibility and the acceptance of the health benefits of cannabis, which may enhance the use of cannabis as a coping mechanism among young adults with depression.

Trends in Prevalence of Cannabis Use Disorder Among U.S. Veterans With and Without Psychiatric Disorders Between 2005 and 2019

OBJECTIVE

Cannabis use disorder diagnoses are increasing among U.S. adults and are more prevalent among people with comorbid psychiatric disorders. Recent changes in cannabis laws, increasing cannabis availability, and higher-potency cannabis may have placed people with cannabis use and psychiatric disorders at disproportionately increasing risk for cannabis use disorder. The authors used Veterans Health Administration (VHA) data to examine whether trends in cannabis use disorder prevalence among VHA patients differ by whether they have psychiatric disorders.

METHODS

VHA electronic health records from 2005 to 2019 (N range, 4,332,165-5,657,277) were used to identify overall and age-group-specific (<35, 35-64, and ≥65 years) trends in prevalence of cannabis use disorder diagnoses among patients with depressive, anxiety, posttraumatic stress, bipolar, or psychotic spectrum disorders and to compare these to corresponding trends among patients without any of these disorders. Given transitions in ICD coding, differences in trends were tested within two periods: 2005-2014 (ICD-9-CM) and 2016-2019 (ICD-10-CM).

RESULTS

Greater increases in prevalence of cannabis use disorder diagnoses were observed among patients with psychiatric disorders compared to those without (difference in prevalence change, 2005-2014: 1.91%, 95% CI=1.87-1.96; 2016-2019: 0.34%, 95% CI=0.29-0.38). Disproportionate increases in cannabis use disorder prevalence among patients with psychiatric disorders were greatest among those under age 35 between 2005 and 2014, and among those age 65 or older between 2016 and 2019. Among patients with psychiatric disorders, the greatest increases in cannabis use disorder prevalences were observed among those with bipolar and psychotic spectrum disorders.

CONCLUSIONS

The findings highlight disproportionately increasing disparities in risk of cannabis use disorder among VHA patients with common psychiatric disorders. Greater public health and clinical efforts are needed to monitor, prevent, and treat cannabis use disorder in this population.

In-Home Cannabis Smoking Among a Cannabis-Using Convenience Sample from the Global Drug Survey: With Weighted Estimates for U.S. Respondents

Introduction: Secondhand and thirdhand tobacco smoke exposure most often occur at home, but little is known about occurrences of in-home cannabis smoking. We ascertained in-home cannabis smoking reported by all cannabis-using (i.e., used in the last 12 months) respondents to the Global Drug Survey (GDS; international-GDS sample), and among U.S. cannabis-using respondents (US-GDS sample). Materials and Methods: We used data collected November 2019-January 2020 for the 2020 GDS, an annual anonymous, cross-sectional survey; respondents were 16+ years old, from 191 countries. We estimated any and daily in-home cannabis smoking in the last 30 days among international-GDS respondents (n=63,797), using mixed effects logistic regression. US-GDS respondents (n=6,580) were weighted to the covariate distribution of the nationally representative 2018 National Survey on Drug Use and Health cannabis-using sample, using inverse odds probability weighting, to make estimates more generalizable to the U.S. cannabis-using population. Results: For the international-GDS cannabis-using respondents, any in-home cannabis smoking was reported by 63.9% of men, 61.9% of women, and 68.6% of nonbinary people; and by age (<25 years old=62.7%, 25-34 years old=65.0%, and 35+ years old=62.8%). Daily in-home cannabis smoking was highest among nonbinary (28.7%) and respondents 35+ years of age (28.0%). For the weighted US-GDS cannabis-using respondents, any in-home cannabis smoking was reported by 49.8% of males and 61.2% of females; and by age (<25 years old=62.6%, 25-34 years old=41.8%, 35+ years old=57.9%). Weighted daily in-home smoking was 23.2% among males and 37.1% among females; by age (<25 years old=34.8%, 25-34 years old=27.8%, and 35+ years old=21.6%). Conclusions: There was high daily cannabis smoking in homes of international-GDS and US-GDS respondents who used cannabis in the last 12 months. In part, due to cannabis legalization, the number of users worldwide has increased over the past decade. Criminal stigma historically associated with cannabis continues to drive those users indoors. In this context, our findings support further investigation of cannabis use behavior to understand how often people are exposed to secondhand and thirdhand cannabis smoke and the consequences of that exposure.

Trends and projection in the proportion of (heavy) cannabis use in Germany from 1995 to 2021

AIMS

To measure the current trends of cannabis use in Germany, measure trends in the proportion of heavy cannabis users and estimate future cannabis use rates.

DESIGN

Repeated waves of the Epidemiological Survey on Substance Abuse, a cross-sectional survey conducted between 1995 and 2021 with a two-stage participant selection strategy where respondents completed a survey on substance use delivered through the post, over the telephone or on-line.

SETTING

Germany.

PARTICIPANTS/CASES

German-speaking participants aged between 18 and 59 years living in Germany who self-reported on their cannabis use in the past 12 months (n = 78 678). With the application of a weighting scheme, the data are nationally representative.

MEASUREMENTS

Questions on the frequency of cannabis use in the past 12 months and self-reported changes in frequency of use due to the COVID-19 pandemic.

FINDINGS

The prevalence of past 12-month cannabis users increased from 4.4% [95% confidence interval (CI) = 3.7, 5.1] in 1995 to 10.0% (95% CI = 8.9, 11.3) in 2021. Modeling these trends revealed a significant increase that accelerated over the past decade. The proportion of heavy cannabis users [cannabis use (almost) daily or at least 200 times per year] among past-year users has remained steady from 1995 (11.4%, 95% CI = 7.7, 16.5) to 2018 (9.5%, 95% CI = 7.6, 11.9), but significantly increased to 15.7% (95% CI = 13.1, 18.8) in 2021 during the COVID-19 pandemic. Extrapolating from these models, the prevalence of 12-month cannabis users in 2024 is expected to range between 10.4 and 15.0%, while the proportion of heavy cannabis users is unclear.

CONCLUSIONS

Trends from 1995 to 2021 suggest that the prevalence of past 12-month cannabis users in Germany will continue to increase, with expected rates between 10.4 and 15.0% for the German-speaking adult population, and that at least one in 10 cannabis users will continue to use cannabis heavily (almost daily or 200 + times in the past year).

Assessing Cannabis Use in People with Psychosis

Introduction: Cannabis use is common in people with psychotic disorders and is associated with the exacerbation of symptoms, poor treatment adherence, and an increased risk of relapse. Accurate assessment of cannabis use is thus critical to the clinical management of psychosis. Discussion: Cannabis use is usually assessed with self-report questionnaires that were originally developed for healthy individuals or people with a cannabis use disorder. Compared to these groups, the pattern of cannabis use and the associated harms in patients with psychosis are quite different. Moreover, in people with psychosis, the accuracy of self-reported use may be impaired by psychotic symptoms, cognitive deficits, and a desire to conceal use when clinicians have advised against it. Although urinary screening for delta-9-tetrahydrocannabinol is sometimes used in the assessment of acute psychotic episodes, it is not used in routinely. Cannabis use could be assessed by measuring the concentration of cannabinoids in urine and blood, but this is rarely done in either clinical settings or research. Conclusion: Using quantitative biological measures could provide a more accurate guide to the effects of use on the disorder than asking patients or using questionnaires.

State-Level Recreational Cannabis Legalization Is Not Differentially Associated with Cannabis Risk Perception Among Children: A Multilevel Regression Analysis

Introduction: As more states pass recreational cannabis laws (RCLs) for adults, there is concern that increasing (and state-sanctioned) cannabis acceptance will result in a reduced perception of risk of harm from cannabis among children. We aimed to discover whether children in states with RCLs had decreased perception of risk from cannabis compared with children in states with illicit cannabis. Methods: We analyzed data from the multisite multistate Adolescent Brain and Cognitive Development Study to determine how the perception of cannabis harm among children (age at baseline: 9-10; N=10,395) changes over time in states with and without RCLs. Using multilevel modeling, we assessed survey responses from children longitudinally across 3 years, adjusting for state-, family-, and participant-level clustering and child-level factors, including demographics (sex, race, and socioeconomic status), religiosity, and trait impulsivity. Results: There was no significant main effect of state RCLs on perceived risk of cannabis use, and no differences in change over time by state RCLs, even after controlling for demographic factors and other risk (e.g., impulsivity) and protective (e.g., religiosity) factors. Conclusions: This analysis indicates that state-level RCLs are not associated with differential perception of cannabis risk among children, even after controlling for demographics, trait impulsivity, and religiosity. Future studies could assess how perception of risk from cannabis changes as children and adolescents continue to mature in states with and without RCLs.

Why Are Adolescent Cannabis Use Disorder Treatment Admissions Declining in the US? The Mediated Pathway of State Treatment Admissions Rates before and after Recreational Cannabis Legalization

Purpose: State-level prevalence data are used to investigate whether recreational cannabis legalization moderates the mediated pathway from the perception of low risk of harm, to cannabis use, to cannabis use disorder (CUD) treatment admissions, among adolescents (age 12-17) in the US. Methods: Annual state prevalence measures of perception of low risk, cannabis use, and CUD treatment admissions between 2008 and 2019 (N = 542 state-year observations) were collected from the National Survey on Drug Use and Health (NSDUH) and the Treatment Episode Dataset - Admissions (TEDS-A). A two-way fixed effects (state and year) moderated mediation model was used to test whether recreational legalization moderated the indirect effect of perception of low risk on treatment admissions via cannabis use. Results: A positive indirect effect of perceiving cannabis as low risk on CUD treatment admissions via cannabis use was observed prior to legalization but not afterwards. After legalization, the positive association of perceiving cannabis as low risk with cannabis use was strengthened, and the positive association of cannabis use with treatment admissions was suppressed, as compared to before legalization. Discussion: Recreational legalization may alter the social acceptability and medical self-administration of cannabis, potentially leading to CUD treatment utilization decline among adolescents even as risk factors for CUD increase. Linking recreational cannabis legalization to advancing awareness of the health risks associated with adolescent cannabis use and promoting adolescent CUD treatment engagement through mHealth approaches and primary care providers are key to addressing potential adolescent health challenges brought about by expanding cannabis legalization.

Adverse Impact of Cannabis on Human Health

Cannabis, the most commonly used recreational drug, is illicit in many areas of the world. With increasing decriminalization and legalization, cannabis use is increasing in the United States and other countries. The adverse effects of cannabis are unclear because its status as a Schedule 1 drug in the United States restricts research. Despite a paucity of data, cannabis is commonly perceived as a benign or even beneficial drug. However, recent studies show that cannabis has adverse cardiovascular and pulmonary effects and is linked with malignancy. Moreover, case reports have shown an association between cannabis use and neuropsychiatric disorders. With growing availability, cannabis misuse by minors has led to increasing incidences of overdose and toxicity. Though difficult to detect, cannabis intoxication may be linked to impaired driving and motor vehicle accidents. Overall, cannabis use is on the rise, and adverse effects are becoming apparent in clinical data sets.

Cross-ancestry genetic investigation of schizophrenia, cannabis use disorder, and tobacco smoking

Individuals with schizophrenia frequently experience co-occurring substance use, including tobacco smoking and heavy cannabis use, and substance use disorders. There is interest in understanding the extent to which these relationships are causal, and to what extent shared genetic factors play a role. We explored the relationships between schizophrenia (Scz), cannabis use disorder (CanUD), and ever-regular tobacco smoking (Smk) using the largest available genome-wide studies of these phenotypes in individuals of African and European ancestries. All three phenotypes were positively genetically correlated (rgs = 0.17 - 0.62). Causal inference analyses suggested the presence of horizontal pleiotropy, but evidence for bidirectional causal relationships was also found between all three phenotypes even after correcting for horizontal pleiotropy. We identified 439 pleiotropic loci in the European ancestry data, 150 of which were novel (i.e., not genome-wide significant in the original studies). Of these pleiotropic loci, 202 had lead variants which showed convergent effects (i.e., same direction of effect) on Scz, CanUD, and Smk. Genetic variants convergent across all three phenotypes showed strong genetic correlations with risk-taking, executive function, and several mental health conditions. Our results suggest that both horizontal pleiotropy and causal mechanisms may play a role in the relationship between CanUD, Smk, and Scz, but longitudinal, prospective studies are needed to confirm a causal relationship.