Recreational cannabis legalization alters associations among cannabis use, perception of risk, and cannabis use disorder treatment for adolescents and young adults

Exploring cannabis consumption stigma in Canada with consideration of age and gender differences

Background

Despite cannabis legalization in Canada, stigma towards cannabis consumers remains evident, particularly toward younger cannabis consumers. Our study examined how stigma towards a young cannabis consumer differed by age and gender. Additionally, we explored the impacts of the participants' cannabis consumption, age, and gender identity on their perceptions of stigma.

Methods

Canadian citizens, ages 18 years and older completed an online cross-sectional survey using an experimental vignette design (N = 1,114). Participants were randomly assigned to read one of six vignettes depicting a cannabis consumer that varied by age (14, 21, and 28 years) and gender (man, woman). Participants completed the Social Distance Survey as the dependent measure of stigma. Two factorial ANOVAs were conducted to assess the impacts of the vignette character's age and gender, as well as the participant's age and gender identity, on stigma.

Results

Participants (Mage = 48.42, SD = 16.64) displayed more stigmatizing attitudes towards adolescent consumers (14-years-old) compared to 21-years-old or 28-years-old consumers. Additionally, older participants (70 + years) displayed more stigmatizing attitudes than younger participants (18-29 and 30-39 years old). Finally, participants who had not consumed cannabis within the past 6-months displayed more stigmatizing attitudes than those who reported any cannabis use frequency.

Conclusions

Stigma remains a concern, particularly toward younger cannabis consumers. These findings highlight the importance of developing targeted, early interventions, and education strategies aimed at reducing stigma, especially among those who hold more stigmatizing attitudes, such as non-cannabis consumers and older individuals, which could help mitigate negative outcomes like decreased help-seeking behavior and social isolation.

Impact Statement

Stigma toward cannabis consumers was greatest for younger consumers (14-years-old), followed by 21 and 28-year-olds. Specifically, older generations (70 + year old's) endorsed more stigma compared to younger generations. There were no main effects on stigma toward cannabis consumers based on the vignette character's gender or research participants' gender identity.

Prevalence of Cannabis Use Disorder Among Primary Care Patients with Varying Frequency of Past-Year Cannabis Use

BACKGROUND

Valid, single-item cannabis screens for the frequency of past-year use (SIS-C) can identify patients at risk for cannabis use disorder (CUD); however, the prevalence of CUD for patients who report varying frequencies of use in the clinical setting remains unexplored.

OBJECTIVE

Compare clinical responses about the frequency of past-year cannabis use to typical use and CUD severity reported on a confidential survey.

PARTICIPANTS

Among adult patients in an integrated health system who completed the SIS-C as part of routine care (3/28/2019-9/12/2019; n = 108,950), 5000 were selected for a confidential survey using stratified random sampling. Among 1688 respondents (34% response rate), 1589 who reported past-year cannabis use on the SIS-C were included.

MAIN MEASURES

We compared patients with varying frequency of cannabis use on the SIS-C (< monthly, monthly, weekly, daily) to survey responses on the Composite International Diagnostic Interview Substance Abuse Module for CUD (any and moderate-severe CUD) and cannabis exposure measures (typical use per-week, per-day). Adjusted multinomial (categorical) and logistic regression (binary), weighted for population estimates, estimated the prevalence of outcomes across frequencies.

KEY RESULTS

Patients were predominantly middle-aged (mean = 43.3 years [SD = 16.9]), male (51.8%), white (78.2%), non-Hispanic (94.0%), and commercially insured (68.9%). The prevalence of any and moderate-severe CUD increased with greater frequency of past-year cannabis use reported on the SIS-C (p-values < 0.001) and ranged from 12.7% (6.3-19.2%) and 0.9% (0.0-2.7%) for < monthly to 44.6% (41.4-47.7%) and 20.3% (17.8-22.9%) for daily use, respectively. Greater frequency of use on the SIS-C in the clinical setting corresponded with greater per-week and per-day use on the confidential survey.

CONCLUSIONS

Among patients who reported past-year cannabis use as part of routine screening, the prevalence of CUD and other cannabis exposure measures increased with greater frequency of cannabis use, underscoring the utility of brief cannabis screens for identifying patients at risk for CUD.

Comorbid Cannabis Use and Mood Disorders Among Adolescents

Adolescence is a unique developmental period marked by increased exploration and risk-taking, as well as important brain development milestones. Many people who use substances will begin using during adolescence, and cannabis is the most commonly used illicit substance among adolescents. For adolescents with mood disorders, cannabis use (and, by extension, cannabis use disorder) is even more likely, and the associated consequences are even more significant. In this review, we explore the assessment of cannabis use disorder among adolescents, the impact of cannabis use on mood symptoms, level-of-care recommendations for adolescents with comorbid cannabis use and mood disorders, and effective treatment options.

Parent Perspectives on Youth Cannabis Use and Mental Health: Impacts, Challenges, and Recommendations

Cannabis use among youth and young adults (YYA) is rising and poses serious mental health risks, especially with the availability of high-potency products. Parents are often the first to observe the potential impacts of cannabis use and are essential in recognizing early warning signs, facilitating treatment, and supporting recovery. However, limited research has examined the perspectives of parents whose children experience severe mental health challenges following cannabis use. To explore parent perspectives, the research team conducted semi-structured interviews with a purposive sample of 13 parents who reported their children used cannabis and experienced mental health issues. Interviews were transcribed and dual coded. A deductive-inductive thematic analysis was used to generate themes. Four themes were identified including (1) cannabis use and mental health, (2) impact on parents and families, (3) treatment experiences, and (4) system recommendations. Parents described how their children's cannabis use either worsened or appeared to trigger severe mental health crises, which increased emotional and financial burdens on their families. Many encountered health care providers who minimized cannabis-related risks, leading to inadequate support during treatment-seeking efforts. Parents also emphasized a lack of public health warnings and insufficient regulatory oversight, calling for better-informed clinicians and more robust public health messaging. These findings highlight an urgent need for family-supportive behavioral health interventions and regulatory reforms to address cannabis-related mental health issues among YYAs.

N-acetylcysteine for youth cannabis use disorder: randomized controlled trial main findings

Cannabis use disorder is particularly prevalent and impairing among young people, and evidence-based treatments are limited. Prior trials of N-acetylcysteine, added to contingency management as a platform behavioral intervention, yielded positive findings in youth but not in adults. This trial sought to rigorously evaluate whether N-acetylcysteine is efficacious in youth when not paired with a robust behavioral treatment platform. Treatment-seeking youth with cannabis use disorder (N = 192, ages 14-21) were randomized to receive a double-blind 12-week course of oral N-acetylcysteine 1200 mg or placebo twice daily; all received weekly medical management and brief behavioral counseling. The primary efficacy outcome was the proportion of negative urine cannabinoid tests during treatment, compared between groups. An array of self-report and urine testing measures were examined secondarily to assess cannabis use reduction and cessation outcomes. The N-acetylcysteine and placebo groups did not differ in proportion of negative urine cannabinoid tests (RR = 0.93, 95% CI = 0.53, 1.64; p = 0.80) or self-reported cannabis abstinence (RR = 1.02, 95% CI = 0.63, 1.65; p = 0.93) during treatment. The mean percentage of cannabis use days and grams of cannabis used per using day decreased over time during treatment but did not differ between groups. More N-acetylcysteine than placebo treated participants reported gastrointestinal adverse events (63/98 versus 37/94, χ21 = 11.9 p < 0.001); adverse events were otherwise similar between groups. Findings indicate that N-acetylcysteine is not efficacious for youth cannabis use disorder when not paired with contingency management, highlighting the potentially crucial role of a robust behavioral treatment platform in facilitating prior positive efficacy findings with N-acetylcysteine.Trial Registration: Clinicaltrials.gov identifier NCT03055377.

Cannabis use, health problems, and criminal offences in Germany: national and state-level trends between 2009 and 2021

The German federal government plans to decriminalise cannabis. The impact of this policy on use prevalence, cannabis-related health and legal problems cannot be fully anticipated and should be viewed in context with current trends. We used routine data on (a) cannabis use (population-based surveys), (b) cannabis-related diagnoses (ICD-10 code F12) in outpatient medical settings and (c) minor law offences (registered violations against the narcotics law for possessing small amounts) to analyse age and sex-specific trends by federal state between 2009 and 2021. To enable comparisons across time and federal state besides crude prevalence rates, age-standardised rates were calculated. Between 2009 and 2021, the age-standardised prevalence of cannabis use (5.7-10.6%), rate of diagnoses (1.1-3.7 per 1,000), and legal offences (1.8-3.1 per 1,000) increased, with the largest increase noted for cannabis-related diagnoses. Relatively, increases were most pronounced for older users (40-to-59-year-olds: use and offences; 35-to-44-year-olds: cannabis-related diagnoses) and rather stagnant for minors. Cannabis use and health problems appear to be more pronounced in Northern and city states, while no clear geographic trend was observed for law offences. Cannabis-related outpatient treatment demand has risen more steeply than use prevalence suggesting an increasing challenge for the health care system. Despite rising rates for documented offences, the long-term implications of law violations on social and occupational life are poorly understood but may be considered for evaluations of the proposed law changes.

Treatment demand for cannabis use problems: analyses of routine data from 30 European countries

Cannabis use and treatment demand has risen in the past decade. Previous analyses of treatment demand are limited by methodological constraints or are outdated. Cross-country differences and trends in cannabis treatment demand are described using data from the European Monitoring Centre for Drugs and Drug Addiction. Two novel indicators are employed: firstly, the cannabis-attributable treatment fraction (CATF) is obtained by dividing the number of treatment entrants for cannabis use problems by the number of treatment entrants for any substance use problem, accounting for possible changes in the reporting system. Secondly, comparing the number of treatment entrants for cannabis use problems to the number of people who use cannabis (near) daily yields the treated-user-ratio (TUR), which considers a proxy for treatment need (frequent use). Across 30 countries with available data, the importance of cannabis in European treatment facilities varies greatly (CATF: min = 3%; max = 65%), with lower estimates in Eastern European countries. Across 20 countries with complete data, the CATF has risen from 29.4% in 2013 to 37.1% in 2020. The TUR calculated on 26 countries suggests that about 3 in 100 frequent users have sought treatment for their cannabis use problems. Over time, treatment demand has increased at a slower pace than treatment need in most countries. One in three treatment entrants for substance use problems in Europe are due to cannabis, with large variations between countries. There are indications for a widening treatment gap for cannabis use problems. In countries liberalising cannabis laws, monitoring changes in treatment access and demand is warranted.

Prolonged incubation with Δ9-tetrahydrocannabinol but not with cannabidiol induces synaptic alterations and mitochondrial impairment in immature and mature rat organotypic hippocampal slices

Cannabis derivatives are among the most widely used psychoactive substances in the world, which leads to growing medical concerns regarding its chronic use and abuse especially among adolescents. Exposure to THC during formative years produces long-term behavioral alterations that share similarities with symptoms of psychiatric and neurodevelopmental disorders. In this study, we have analyzed the functional and molecular mechanisms that might underlie these alterations. Rat organotypic hippocampal slices were cultured for 2 days (immature) or 10 days (mature) in vitro and then exposed for 7 days to THC (1 µM) or CBD (1 µM). At the end of the treatment, slices were analyzed by Western blotting, electrophysiological recordings, RT-PCR, and fluorescence microscopy to explore the molecular and functional changes in the hippocampus. A prolonged (7-day) exposure to THC reduced the expression levels of pre- (synaptophysin, vGlut1) and post-synaptic (PSD95) proteins in both immature and mature slices, whereas CBD significantly increased the expression levels of PSD95 only in immature slices. In addition, THC significantly reduced the passive properties and the intrinsic excitability of membranes and increased sEPSCs in CA1 pyramidal cells of immature but not mature slices. Exposure to both cannabinoids impaired mitochondrial function as detected by the reduction of mRNA expression levels of mitobiogenesis genes such as VDAC1, UCP2, and TFAM. Finally, THC but not CBD caused tissue disorganization and morphological modifications in CA1 pyramidal neurons, astrocytes and microglia in both immature and mature slices. These results are helpful to explain the specific vulnerability of adolescent brain to the effects of psychotropic cannabinoids.

Systematic review and meta-analysis on the effects of chronic peri-adolescent cannabinoid exposure on schizophrenia-like behaviour in rodents

BACKGROUND

The link between cannabis use and schizophrenia is well-established in epidemiological studies, especially among adolescents with early-onset use. However, this association in rodent models is less clear. This meta-analysis examined the effects of adolescent cannabinoid exposure on distinct schizophrenia-like behaviours in rodents and how experimental variations influence outcomes.

METHODS

Following a pre-registered protocol (CRD42022338761), we searched PubMed, Ovid Medline, Embse and APA PsychInfo for English-language original studies until May 2024. We synthesised data from experiments on schizophrenia-like behaviour in rats and mice after repeated peri-pubertal (onset between P23-P45) cannabinoid exposure. Risk of bias was assessed using the SYRCLE's tool.

RESULTS

We included 359 experiments from 108 articles across 9 behavioural tests. We found meta-analytic evidence supporting that CB1R agonists, both natural and synthetic, elicited broad schizophrenia-like behavioural alterations, including impaired working memory [g  = -0.56; (CI: -0.93, -0.18)], novel object recognition [g = -0.66; (CI: -0.97, -0.35)], novel object location recognition [g = -0.70; (CI: -1.07, -0.33]), social novelty preference [g = -0.52; (CI: -0.93, -0.11)], social motivation [g = -0.21; (CI: -0.42, -0.00)], pre-pulse inhibition [g = -0.43; (CI: -0.76, -0.10)], and sucrose preference [g = -0.87; (CI: -1.46, -0.27)]. By contrast, effects on novelty-induced locomotion were negligible. Subgroup analyses revealed similar effects across sexes and species. Substantial variance in the protocols and moderate-to-high heterogeneity in behavioural outcomes were observed. We found CBD may enhance fear memory recall, but data was limited.

DISCUSSION

This is the first meta-analysis to comprehensively assess the link between cannabinoids and schizophrenia-like behaviours in rodents. Our results support epidemiological links between early cannabis use and schizophrenia-like phenotypes, confirming the utility of animal models. Standardising protocols will optimise models to strengthen reproducibility and comparisons, our work provides a framework for refining rodent models to elucidate biological pathways linking cannabis and schizophrenia.

Identifying predictors of multi-year cannabis vaping in U.S. Young adults using machine learning

INTRODUCTION

Increasing number of current cannabis users report using a vaporized form of cannabis and young adults are most likely to vape cannabis. However, the number of studies on cannabis vaping is limited, and predictors of cannabis vaping among U.S. young adults remain unclear. Previous studies on cannabis vaping have known limitations, as they (1) relied heavily on regression-based approaches that often fail to examine complex and non-linear interactive effects, (2) focused on examining cannabis vaping initiation but not on its use over multiple years, and (3) failed to account for recreational cannabis legalization (RCL) status.

METHODS

This study was a secondary analysis of the restricted use files of the Population Assessment of Tobacco and Health Study, Waves 4-6 (December 2016-November 2021). A two-stage machine learning approach, which included Least Absolute Shrinkage and Selection Operator (LASSO) and Classification and Regression Tree (CART), was used to identify predictors of multi-year cannabis vaping while accounting for state-level RCL status among a representative sample of U.S. young adults.

RESULTS

Stratified CART created a five-terminal-node prediction model for states with RCL (split by cannabis use, cigarette use, bullying behavior, and ethnicity) and a different five-terminal-node prediction model for states without RCL (split by cannabis use, heroin use, nicotine vaping, and hookah use).

CONCLUSIONS

Characteristics predicting multi-year cannabis vaping appear to differ from those of cannabis vaping initiation. Results also highlight the importance of accounting for RCL status because predictors of cannabis vaping may differ for individuals living in states with and without RCL.

Cannabis use disorder and substance use treatment among U.S. adults

INTRODUCTION

Recent expansion of cannabis legalization in multiple states calls for reexamination of the prevalence of cannabis use, cannabis use disorder (CUD), and the associations between CUD severity and substance use treatment. We used Andersen's behavioral model of healthcare use as the conceptual/analytic framework for examining treatment use.

METHODS

We used data from the 2022 National Survey on Drug Use and Health (NSDUH; N = 47,100, age 18+) to describe the prevalence of past-year cannabis use, CUD and CUD severity, other substance use disorders, and substance use treatment. We compared sociodemographic, mental health, healthcare use, and cannabis and other substance use characteristics by CUD severity. Finally, we used logistic regression models to examine the associations between CUD severity and substance use treatment.

RESULTS

Of the U.S. adult population, 23.0 % used cannabis in the past year; 7.0 % had a CUD (3.9 % mild, 1.9 % moderate, and 1.2 % severe CUD); and 4.7 % received substance use treatment. Of past-year cannabis users, 30.3 % had CUD (16.9 % mild, 8.4 % moderate, and 5.0 % severe CUD), and 9.6 % received substance use treatment. Cannabis users had 3-4 times higher rates of other substance use disorders than nonusers. Of those with CUD, 38.4 % had moderate/severe mental illness, 52.4 % had other substance use disorders, and 16.5 % received substance use treatment. Among all cannabis users, moderate (aOR [adjusted odds ratios] = 1.48, 95 % CI = 1.03-2.13) and severe (aOR = 2.57, 95 % CI = 1.60-4.11) CUDs were associated with greater odds of substance use treatment. Among cannabis users without nicotine dependence and alcohol, opioid, tranquilizer/sedative, and stimulant use disorders, only severe CUD (aOR = 6.03, 95 % CI = 3.37-10.78) was associated with greater odds of substance use treatment.

CONCLUSIONS

This study shows increased prevalence of cannabis use and CUD among U.S. adults, and with or without other substance use disorders, CUD was associated with greater odds of substance use treatment. However, the overall low rate of treatment use among those with CUD is concerning. Healthcare providers need to provide education for both medical and recreational users on the development of tolerance and dependence. Harm reduction strategies to minimize the negative consequences of CUD are also needed.

Perception of Risk of Harm from Cannabis Use Among Women of Reproductive Age with Disabilities

Objectives: To examine perceived risk of harm from weekly cannabis use among reproductive-aged women with disabilities. Methods: Using data from the 2021 National Survey on Drug Use and Health, we assessed perceived risk of harm associated with weekly cannabis use among women of reproductive age by disability status. Disabilities included sensory, cognitive, and those related to daily activities. Logistic regression was employed to examine correlates of risk perception associated with weekly cannabis in this subpopulation of women. Results: A significantly higher percentage of women with any disability perceived no risk associated with weekly cannabis use (37.9%) compared to those with no disabilities (26.1%). Approximately, 60.0% of women with disabilities who used cannabis in the past 12 months perceived no risk of harm from weekly cannabis use. Overall, women with disabilities and cannabis use in the past 12 months had higher adjusted odds (AOR=2.90, 95% CI=2.10-4.10) of perceiving no risk associated with weekly use of cannabis compared to women without any disability and no cannabis use. Other significant factors associated with an increased likelihood of perceiving no risk of harm from weekly use of cannabis included younger women, having higher income, being in good health, and using alcohol or tobacco. Conclusions: Perceived risk of harm associated with weekly cannabis use is particularly low among women with disabilities who use cannabis. Given current attitudes toward cannabis as a harmless drug, and the potential adverse health outcomes, it is imperative to monitor and understand women's perceptions of risk of harm from cannabis use for clinical guidance, provider and patient education, and public health programs to support evidence-based approaches in addressing its use among vulnerable populations such as those of reproductive age with disabilities.

Association of vaping with respiratory symptoms in U.S. young adults: Nicotine, cannabis, and dual vaping

INTRODUCTION

Although studies have found nicotine and cannabis vaping to be individually associated with respiratory symptoms, little is known about the harm of dual vaping. We aim to assess the association of nicotine-only, cannabis-only, and dual vaping with respiratory symptoms.

METHODS

Using a national sample of 8033 U.S. young adults (ages 18-24) interviewed in 2021, we employed multivariable logistic regressions to assess the association between vaping behaviors and past 12-month respiratory outcomes.

RESULTS

Of all participants, 75.4 % did not vape, 15.0 % vaped nicotine only, 4.7 % vaped cannabis only, and 4.9 % vaped both. Compared with no vaping, nicotine-only vaping was associated with sounding wheezy (aPR = 1.75, 95 % CI, 1.28-2.39) and dry cough at night (aPR = 1.43, 95 % CI, 1.19-1.72). Cannabis-only vaping was also associated with these two symptoms, with aPRs at 1.82 (95 % CI, 1.15-2.88) and 1.61 (95 % CI, 1.18-2.21), respectively. In addition to these two symptoms (aPR = 2.24, 95 % CI, 1.42-3.54 for sounding wheezy, and aPR = 1.50, 95 % CI, 1.01-2.22 for dry cough at night), dual vaping was associated with wheezing or whistling (aPR = 1.93, 95 % CI, 1.23-3.04) and high level of respiratory symptoms (aPR = 2.02, 95 % CI, 1.24-3.32). Compared with non-frequent vaping, cannabis-only and dual frequent vaping were associated with higher risks of wheezing or whistling.

CONCLUSIONS

Nicotine-only and cannabis-only vaping were associated with two respiratory symptoms while dual vaping with four. The elevated respiratory risk of dual vaping warrants future research on the underlying mechanisms of different vaping behaviors and respiratory outcomes.

Intensifying Substance Use Trends among Youth: A Narrative Review of Recent Trends and Implications

PURPOSE OF REVIEW

Substance use among adolescents and young adults remains a critical public health concern, with patterns shifting dramatically in recent years. This narrative review examines trends in substance use behaviors during and following the COVID-19 pandemic.

RECENT FINDINGS

Epidemiologic evidence shows declines in the proportion of youth who are using most substances but intensified consumption patterns with rising levels of disorder among adolescents who use substances. This picture may reflect the greater potency, availability and accessibility of substances, vulnerabilities related to poor mental health, minoritization, as well as social factors including pandemic stressors, commercial and regulatory forces - in short, features of the agent (substance), host (person), and environment (context), consistent with a public health formulation. Understanding trends in youth substance use and related problems, especially in the context of contributing factors, is critical for informing clinical care strategies and public health interventions to improve outcomes for youth across diverse populations.

Multilevel associations of peer cognitive factors and adolescent cannabis use in a legal recreational cannabis region

Background

Cannabis use can have unintended, harmful consequences for adolescents, a developmental group that struggles with heightened pressure to align with peer attitudes and behaviors. The role of social-cognitive factors in shifting cannabis use dynamics remains under explored, particularly in states where recreational cannabis use is legal.

Objectives

The present study examined multilevel longitudinal associations between resistance to peer influence, peer norms, and adolescent cannabis use over the course of 12 months.

Method

Participants were N=204 adolescents ages 15-19 (M age = 18.68; 67% female) recruited via community outreach after the legalization of adult (age 21+) recreational cannabis use in the Portland, Oregon metropolitan region. Eligible participants endorsed 1+ heavy episodic drinking (HED) episode in the prior two months. Data were collected across four timepoints over 12 months. Multilevel latent growth curve modeling investigated associations between time-varying cognitive factors (resistance to peer influence, peer norms) and two cannabis outcomes (hazardous use, past-month use).

Results

Findings showed individual increases in hazardous cannabis use over time were significantly associated with adolescents reporting higher peer norms (i.e., higher perceived prevalence and frequency of peer cannabis use) and lower resistance to peer influence. When assessing between-adolescent differences, hazardous cannabis use was only associated with peer norms. Individual variation over time and between-adolescent differences on past-month cannabis use was associated with peer norms, but not resistance to peer influence.

Conclusions

Evolving cognitive factors like resistance to peer influence and peer norms may enhance understanding of longitudinal changes in hazardous cannabis use among adolescents and implicate helpful targets for prevention and intervention. It is a public health priority to identify factors that contribute to adolescent use trajectories in this period of growing cannabis legislation in order to guide the development of impactful prevention and intervention strategies.

Cannabis, Endocannabinoids and Brain Development: From Embryogenesis to Adolescence

The endocannabinoid signalling system (ECS) plays a critical role from the very beginning of embryogenesis. Accordingly, the ECS is engaged early on in nervous system development, starting from neurulation, supported by the identification of ECS components-both receptors and enzymes controlling endocannabinoid metabolism-at these early stages. In particular, regarding the brain, the ECS is involved in the tightly regulated sequence of events that comprise brain development, from neurogenesis to neuronal migration, morphological guidance for neuronal connectivity, and synaptic circuitry refinement. The importance of this broad role of the ECS across various brain development processes is further underscored by the growing understanding of the consequences of cannabis exposure at different developmental stages. Despite the considerable knowledge we have on the role of the ECS in brain development, significant gaps in our understanding remain, particularly regarding the long-term impact and underlying mechanisms of cannabis exposure at different developmental stages. This review provides an overview of the current state of knowledge on the role of the ECS throughout brain development, from embryogenesis to adulthood, and discusses the impact of cannabis exposure, especially during adolescence-a critical period of circuitry maturation and refinement coinciding with an increased risk of cannabis use.

Editorial: Cannabis Legalization and Youth Cannabis Use: Findings From an Updated Systematic Review and Meta-Analysis

Cannabis legalization is gaining traction in the United States, with 24 states having legalized recreational cannabis sales and 38 states having legalized medical cannabis sales. A possible unintended consequence of such widespread legalization is the effect that such policy change will have on youth (adolescents and young adults), whose neurodevelopment may be disrupted by cannabis use.1 Indeed, cannabis use in youth can lead to significant adverse psychosocial and health outcomes.1 Specifically, a major concern is that youth cannabis use may increase in the setting of legalization because of greater availability and acceptability. This concern has prompted studies of youth cannabis use patterns in states that have legalized recreational cannabis (RCL), have legalized medical cannabis (MCL), and have legalized neither (NL). Prior publications have had limited post-legalization data because of recreational cannabis legalization occurring only very recently and in a small number of states.2 The most recent meta-analysis exploring impacts of legalization on youth cannabis use only studies with data from 2016 and prior (only 4 years since the first states legalized recreational cannabis).2 Since then, 7 states have adopted MCL and 15 states have adopted RCL, prompting the need for an updated review of the literature. Pawar et al.3 conducted a systematic review and meta-analysis assessing associations between state-level cannabis laws and past-month cannabis use among US youth using studies published up to 2023, providing a timely and important evaluation of the impacts of cannabis legalization on youth cannabis use.

Telehealth counseling plus mHealth intervention for cannabis use in emerging adults: Development and a remote open pilot trial

INTRODUCTION

To improve treatment access for emerging adults with cannabis use disorder (CUD), we developed a telehealth counseling-plus-mHealth intervention and remotely conducted a single-arm open pilot study to preliminarily evaluate its feasibility in primary care.

METHODS

A multidisciplinary team including youth developed the intervention using the structure of the MOMENT intervention: two weekly counselor-delivered Motivational Enhancement Therapy (MET) sessions, then two weeks of smartphone surveys (4 prompted/day) querying socioemotional contexts and cannabis use, with pre-programmed messages on report of personal triggers for use (Ecological Momentary Intervention; EMI). The team adapted the MET for virtual delivery; created material to enhance self-reflection, plan behavior change, and anticipate withdrawal; shortened the sessions; and tested them with five youth actors. EMI messages were created to align with the MET and programmed to minimize repetition. Patients aged 18-25 using recreational cannabis ≥3 days/week were recruited from an urban medical practice. Participants received the intervention and responded to surveys on satisfaction and burden. At baseline, post-intervention, and two months, participants reported behavior change readiness/importance/confidence and cannabis use. EMI engagement was calculated as % days with ≥1 phone survey completed.

RESULTS

Fourteen eligible patients enrolled; 79 % used cannabis daily/near-daily and 100 % reported use problems. All completed both MET sessions and responded to EMI surveys. All agreed/strongly agreed that they felt respected by, comfortable with, and trust for the counselor and that the activities and discussion were helpful; all rated the MET sessions as very good/excellent. Technical issues were infrequent and minor. Median EMI engagement was 100 % (≥1 report/day) in each week. Behavior change confidence was higher post-intervention and importance and confidence were higher at two months vs. baseline. By two months, 11 participants had started to change cannabis use; median percent days of use in the past 30 days declined by 27 % and average times of use per use day declined by 28 %. All rated intervention quality as good, very good, or excellent.

CONCLUSIONS

Emerging adults were highly satisfied and engaged with a telehealth MET counseling-plus-mHealth EMI intervention for cannabis use and reported higher motivation to change cannabis use and less use post-intervention and at 2-month follow-up.

Considerations before the legalization of recreational and medical cannabis in Iran

Cultural perspectives on marijuana consumption have undergone substantial reforms in recent years, and the decriminalization and legalization of cannabis are a matter of debate now. The conditions of determining factors are not the same among societies; therefore, each society should decide independently. Herein, the considerations that Iran should contemplate before legalizing cannabis were addressed. Global trends, social status, influence on the judiciary, costs, health effects, quality control, shifting substance use patterns, societal detachment, and changes in prevalence were the discussed determinant factors. Now that religious, cultural, and legal status has suppressed the increase in prevalence, legalization of recreational use that leads to a significant increase in consumption is not advisable. However, the legalization and production of medical cannabis should be on the agenda, as none of the items that hinder the legalization of recreational cannabis do not apply to medical cannabis. Research should continue to reduce uncertainties, especially by combining big data from sale systems of areas where recreational cannabis use has been legalized with big data sources like social media.

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.

PLAIN LANGUAGE SUMMARY

Cannabis laws have changed dramatically throughout the United States over the past 25 years. It is important to determine if medical or recreational cannabis legalization are associated cannabis use in youth. The authors conducted a systematic review and meta-analysis to investigate the associations between state-level cannabis laws and past-month cannabis use in adolescents and young adults. The authors identified 64 articles and found that recreational cannabis laws were associated with a modest but significant higher odds of past-month cannabis use. In contrast, medical cannabis laws were not associated with past-month youth cannabis use. Analysis of more recent studies suggested a rise in cannabis use among youth. The authors conclude that further research is needed to better understand the impact of recreational cannabis legalization on youth.

Regular cannabis use modulates gamma activity in brain regions serving motor control

BACKGROUND

People who regularly use cannabis exhibit altered brain dynamics during cognitive control tasks, though the impact of regular cannabis use on the neural dynamics serving motor control remains less understood.

AIMS

We sought to investigate how regular cannabis use modulates the neural dynamics serving motor control.

METHODS

Thirty-four people who regularly use cannabis (cannabis+) and 33 nonusers (cannabis-) underwent structured interviews about their substance use history and performed the Eriksen flanker task to map the neural dynamics serving motor control during high-density magnetoencephalography (MEG). The resulting neural data were transformed into the time-frequency domain to examine oscillatory activity and were imaged using a beamforming approach.

RESULTS

MEG sensor-level analyses revealed robust beta (16-24 Hz) and gamma oscillations (66-74 Hz) during motor planning and execution, which were imaged using a beamformer. Both responses peaked in the left primary motor cortex and voxel time series were extracted to evaluate the spontaneous and oscillatory dynamics. Our key findings indicated that the cannabis+ group exhibited weaker spontaneous gamma activity in the left primary motor cortex relative to the cannabis- group, which scaled with cannabis use and behavioral metrics. Interestingly, regular cannabis use was not associated with differences in oscillatory beta and gamma activity, and there were no group differences in spontaneous beta activity.

CONCLUSIONS

Our findings suggest that regular cannabis use is associated with suppressed spontaneous gamma activity in the left primary motor cortex, which scales with the degree of cannabis use disorder symptomatology and is coupled to behavioral task performance.

Disproportionate increase in cannabis use among people with serious psychological distress and associations with psychiatric service use in the United States, 2009-2019

BACKGROUND

Cannabis use is on the rise, but it is unclear how use is changing among individuals with serious psychological distress (SPD) compared to the general population as well as what associations this may have with mental health service use.

METHODS

Retrospective cohort study using the National Survey on Drug Use and Health (NSDUH) 2009-19 public use files of 447,228 adults aged ≥ 18 years. Multivariable logistic regression and predictive margin methods were used to estimate linear time trends in any and greater-than-weekly levels of cannabis use by year and SPD status and rates of psychiatric hospitalization and outpatient mental health care.

FINDINGS

Rates of any and weekly-plus cannabis use increased similarly among individuals with SPD compared to those without from 200 to 2014 but more rapidly in SPD every year from 2015 to 2019 (p < 0.001). Among individuals with SPD, no use was associated with a 4.2 % probability of psychiatric hospitalization, significantly less than less-than-weekly (5.0 %, p = 0.037) and weekly-plus cannabis use (5.1 %, p = 0.028). For outpatient mental health care, no use was associated with a 27.4 % probability (95 % CI 26.7-28.1 %) of any outpatient care, significantly less than less than weekly use (32.6 % probability, p < 0.001) and weekly-plus use (29.9 % probability, p = 0.01).

CONCLUSIONS

Cannabis use is increasing more rapidly among individuals with SPD than the general population, and is associated with increased rates of psychiatric hospitalization and outpatient service use. These findings can inform policy makers looking to tailor regulations on advertising for cannabis and develop public health messaging on cannabis use by people with mental illness.

Prescription Digital Therapeutics for Substance Use Disorder in Primary Care: Mixed Methods Evaluation of a Pilot Implementation Study

BACKGROUND

Delivering prescription digital therapeutics (ie, evidence-based interventions designed to treat, manage, or prevent disorders via websites or smartphone apps) in primary care could increase patient access to substance use disorder (SUD) treatments. However, the optimal approach to implementing prescription digital therapeutics in primary care remains unknown.

OBJECTIVE

This pilot study is a precursor to a larger trial designed to test whether implementation strategies (practice facilitation [PF] and health coaching [HC]) improve the delivery of prescription digital therapeutics for SUDs in primary care. This mixed methods study describes outcomes among patients in the 2 pilot clinics and presents qualitative findings on implementation.

METHODS

From February 10 to August 6, 2021, a total of 3 mental health specialists embedded in 2 primary care practices of the same integrated health system were tasked with offering app-based prescription digital therapeutics to patients with SUD. In the first half of the pilot, implementation activities included training and supportive tools. PF (at 1 clinic) and HC (at 2 clinics) were added in the second half. All study analyses relied on secondary data, including electronic health records and digital therapeutic vendor data. Primary outcomes were the proportion of patients reached by the prescription digital therapeutics and fidelity related to ideal use. We used qualitative methods to assess the adherence to planned activities and the barriers and facilitators to implementing prescription digital therapeutics.

RESULTS

Of all 18 patients prescribed the apps, 10 (56%) downloaded the app and activated their prescription, and 8 (44%) completed at least 1 module of content. Patients who activated the app completed 1 module per week on average. Ideal use (fidelity) was defined as completing 4 modules per week and having a monthly SUD-related visit; 1 (6%) patient met these criteria for 10 weeks (of the 12-week prescription period). A total of 5 (28%) patients had prescriptions while HC was available, 2 (11%) were successfully contacted, and both declined coaching. Clinicians reported competing clinical priorities, technical challenges, and logistically complex workflows in part because the apps required a prescription. Some pilot activities were impacted by staff turnover that coincided with the COVID-19 pandemic. The facilitators to implementation were high engagement and the perception that the apps could meet patient needs.

CONCLUSIONS

The pilot study encountered the barriers to implementing prescription digital therapeutics in a real-world primary care setting, especially staffing shortages, turnover, and competing priorities for clinic teams. The larger randomized trial will clarify the extent to which PF and HC improve the implementation of digital therapeutics.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04907045; https://clinicaltrials.gov/study/NCT04907045.

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.

Age-dependent association of cannabis use with risk of psychotic disorder

BACKGROUND

Epidemiologic research suggests that youth cannabis use is associated with psychotic disorders. However, current evidence is based heavily on 20th-century data when cannabis was substantially less potent than today.

METHODS

We linked population-based survey data from 2009 to 2012 with records of health services covered under universal healthcare in Ontario, Canada, up to 2018. The cohort included respondents aged 12-24 years at baseline with no prior psychotic disorder (N = 11 363). The primary outcome was days to first hospitalization, ED visit, or outpatient visit related to a psychotic disorder according to validated diagnostic codes. Due to non-proportional hazards, we estimated age-specific hazard ratios during adolescence (12-19 years) and young adulthood (20-33 years). Sensitivity analyses explored alternative model conditions including restricting the outcome to hospitalizations and ED visits to increase specificity.

RESULTS

Compared to no cannabis use, cannabis use was significantly associated with psychotic disorders during adolescence (aHR = 11.2; 95% CI 4.6-27.3), but not during young adulthood (aHR = 1.3; 95% CI 0.6-2.6). When we restricted the outcome to hospitalizations and ED visits only, the strength of association increased markedly during adolescence (aHR = 26.7; 95% CI 7.7-92.8) but did not change meaningfully during young adulthood (aHR = 1.8; 95% CI 0.6-5.4).

CONCLUSIONS

This study provides new evidence of a strong but age-dependent association between cannabis use and risk of psychotic disorder, consistent with the neurodevelopmental theory that adolescence is a vulnerable time to use cannabis. The strength of association during adolescence was notably greater than in previous studies, possibly reflecting the recent rise in cannabis potency.

Navigating the Grey Zone: The Impact of Legislative Frameworks in North America and Europe on Adolescent Cannabis Use-A Systematic Review

OBJECTIVES

This paper aims to systematically review the impact of legislative framework changes in North America and Europe on adolescent cannabis use. It not only seeks to examine the prevalence of adolescent marijuana use following legislative changes but also to identify the driving forces behind fluctuations in use and to address the gaps left by previous studies.

METHODS

A systematic literature review was conducted in selected databases. After screening English-language publications dating from 2013 to 2023 (n = 453 studies), 24 met the inclusion criteria. Articles were considered if they analyzed the impact of legislative changes on adolescent cannabis use in countries across North America and Europe.

SYNTHESIS

The overall findings suggest an inconsistency regarding the prevalence of cannabis use among youth and adolescents following policy changes. The effects of modifications in cannabis policies on marijuana consumption are complex and influenced by various factors. These include the details of legislation, societal perspectives, enforcement methods, socioeconomic status, and cultural background.

CONCLUSIONS

The results of this analysis reveal a nuanced reality. Although research suggests a rise in cannabis use after legalization, there are variations in the outcomes observed. This highlights the significance of considering context and demographics. Moreover, studies shed light on how specific policy changes, such as depenalization, can affect cannabis use.

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.

Investigating Cannabis-Use Among Students Attending High Schools Within the Cherokee Nation Reservation 2017 and 2019

Oklahoma's medical cannabis is some of the least restrictive in the US. Previous research suggests that American Indian/Alaska Native (AIAN) have higher rates of cannabis use than other racial or ethnic groups. The goals of this paper are, first, to look at cannabis use among high school students living on the Cherokee Nation Reservation before (2017) and after (2019) medical cannabis because legal in Oklahoma (2018) utilizing the Cherokee Nation Youth Risk Behavior Survey (CNYRBS). Second, to describe the socio-demographic characteristics of youth using cannabis in the Cherokee Nation Reservation. Data were retrieved from the 2017 and 2019 CNYRBS. The data for this study included 1,216 high school students who completed the 2017 and 1,476 who completed the 2019 CNYRBS. After removal of incomplete records, there were 2,602 students whose data was analyzed in this study. Data were weighted to be representative of public-school students attending grades 9-12 within Cherokee Nation Reservation. Despite the legalization of medical cannabis in Oklahoma in 2018, there was no change in cannabis use among youth between 2017 and 2019. There were variations in cannabis use based on demographic factors and other substance uses. AIAN individuals had higher odds of current cannabis use compared to non-Hispanic White students, but there were no differences based on ethnicity. Additionally, the use of cigarettes, e-cigarettes, alcohol, and illegal drugs were associated with increased odds of cannabis use among both current and former users compared to those who had never used it. There was no spike in use among youth at least immediately after the legalization of cannabis in the Cherokee Nation Reservation. There were socio-demographic as well as substance use disparities in the use of cannabis.

Cannabis use in the United States and its impact on gastrointestinal health

In recent years, the legalization and social acceptability of cannabis use have increased in the United States. Concurrently, the prevalence of cannabis use has continued to rise, and cannabis products have diversified. There are growing concerns regarding the health effects of regular and high-potency cannabis use, and new research has shed light on its potentially negative effects. Here, we review evidence of the gastrointestinal (GI) effects of cannabis and cannabinoids. Dysregulation of the endocannabinoid system might contribute to various GI disorders, including irritable bowel syndrome and cyclic vomiting syndrome, and endocannabinoids have been found to regulate visceral sensation, nausea, vomiting, and the gut microbiome. Cannabis has been shown to have antiemetic properties, and the US Food and Drug Administration has approved cannabis-based medications for treating chemotherapy-induced nausea and vomiting. Yet, chronic heavy cannabis use has been linked to recurrent episodes of severe nausea and intractable vomiting (cannabinoid hyperemesis syndrome). Given the considerable heterogeneity in the scientific literature, it is unclear if cannabinoid hyperemesis syndrome is truly a distinct entity or a subtype of cyclic vomiting that is unmasked by heavy cannabis use and the associated dysregulation of the endocannabinoid system. The changes in cannabis legalization, availability, and public risk perceptions have outpaced research in this area and there is a need for robust, prospective, large-scale studies to understand the effects of cannabis use on GI health.

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.

A national study of clinical discussions about cannabis use among Veteran patients prescribed opioids

BACKGROUND

The Veterans Health Administration tracks urine drug tests (UDTs) among patients on long-term opioid therapy (LTOT) and recommends discussing the health effects of cannabis use.

OBJECTIVE

To determine the occurrence of cannabis-related discussions between providers and patients on LTOT during six months following UDT positive for cannabis, and examine factors associated with documenting cannabis use.

DESIGN

We identified patients prescribed LTOT with a UDT positive for cannabis in 2019. We developed a text-processing tool to extract discussions around cannabis use from their charts.

SUBJECTS

Twelve thousand seventy patients were included. Chart review was conducted on a random sample of 1,946 patients.

MAIN MEASURES

The presence of a cannabis term in the chart suggesting documented cannabis use or cannabis-related discussions. Content of those discussions was extracted in a subset of patients. Logistic regression was used to examine the association between patient factors, including state of residence legal status, with documentation of cannabis use.

KEY RESULTS

Among the 12,070 patients, 65.8% (N = 7,948) had a cannabis term, whereas 34.1% (N = 4,122) of patients lacked a cannabis term, suggesting that no documentation of cannabis use or discussion between provider and patient took place. Among the subset of patients who had a discussion documented, 47% related to cannabis use for medical reasons, 35% related to a discussion of VA policy or legal issues, and 17% related to a discussion specific to medical risks or harm reduction strategies. In adjusted analyses, residents of states with legalized recreational cannabis were less likely to have any cannabis-related discussion compared to patients in non-legal states [OR 0.73, 95% CI 0.64-0.82].

CONCLUSIONS

One-third of LTOT patients did not have documentation of cannabis use in the chart in the 6 months following a positive UDT for cannabis. Discussions related to the medical risks of cannabis use or harm reduction strategies were uncommon.

General and Domain-Specific Perceived Risk Demonstrate Unique Associations with Cannabis Use, Negative Outcomes, and Motivation to Change among Undergraduate Students

College student cannabis use is at an all-time high. Although frequent heavy cannabis use is related to cannabis problems, perceived risk of cannabis use is rapidly decreasing. Yet, it is unknown whether specific domains of risk perceptions (general and domain-specific risk, risk to others and personal risk) are related to more cannabis use or related problems. Thus, among 130 undergraduates who reported past-month cannabis use, the present study conducted secondary analyses to test whether, for both perceived risk to others and perceived personal risk: (1) general perceived risk was associated with cannabis-related outcomes (i.e., use, negative consequences, cannabis use disorder (CUD) symptoms, motivation to change), (2) seven specific domains of perceived risk were related to cannabis outcomes, and (3) domain-specific perceived risk was related to cannabis use frequency. General perceived risk to others was negatively associated with cannabis use frequency whereas general perceived personal risk was positively associated with cannabis-related negative consequences, CUD symptoms, and importance and readiness to change. Greater legal and withdrawal/dependence risks were uniquely related to several outcomes (e.g., CUD symptoms). Participants who used cannabis frequently perceived more personal risk in most risk domains and less general risk to others than those who used infrequently. Findings suggest personal risk is an important component to consider when assessing perceived risk of cannabis use and focusing on both general and domain-specific risks may provide valuable insight for future prevention and intervention efforts.

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.

Behavioral economic analysis of legal and illegal cannabis demand in Spanish young adults with hazardous and non-hazardous cannabis use

BACKGROUND

In October 2021, a legal framework that regulates cannabis for recreational purposes in Spain was proposed, but research on its potential impacts on cannabis use is currently limited. This study examined the reliability and discriminant validity of two Marijuana Purchase Tasks (MPTs) for measuring hypothetical legal and illegal cannabis demand, and to examine differences in demand of both commodities in young adults at hazardous vs. non-hazardous cannabis use risk levels.

METHODS

A total of 171 Spanish young adults [Mage = 19.82 (SD = 1.81)] with past-month cannabis use participated in a cross-sectional study from September to November 2021. Two 27-item MPTs were used to estimate hypothetical demand for legal and illegal cannabis independently. The Cannabis Use Disorder Identification Test (CUDIT-R) was used to assess hazardous cannabis use and test for discriminant validity of the MPTs. Reliability analyses were conducted using Classical Test Theory (Cronbach's alpha) and Item Response Theory (Item Information Functions).

RESULTS

The MPT was reliable for measuring legal (α = 0.94) and illegal (α = 0.90) cannabis demand. Breakpoint (price at which demand ceases), and Pmax (price associated with maximum expenditure) were the most sensitive indicators to discriminate participants with different levels of the cannabis reinforcing trait. No significant differences between legal and illegal cannabis demand in the whole sample were observed, but hazardous vs. non-hazardous users showed higher legal and illegal demand, and decreased Breakpoint and Pmax if cannabis were legal vs illegal.

CONCLUSION

The MPT exhibits robust psychometric validity and may be useful to inform on cannabis regulatory science in Spain.

Youth cannabis use and subsequent health service use for mood and anxiety disorders: A population-based cohort study

Epidemiologic research suggests a modest association between youth cannabis use and mood and anxiety disorders (MADs). However, current evidence is based mostly on cohort studies using data from the 20th century when cannabis was significantly less potent than today. We linked population-based survey data from 2009 to 2012 with administrative records of health services covered under universal healthcare up to 2017. The cohort included youth aged 12 to 24 years at baseline living in Ontario, Canada with no prior MAD health service use (n = 8,252). We conducted a multivariable Cox model to estimate the association between cannabis use frequency (never, Collapse

Key Words

• Anxiety disorders
• Cannabis
• Mood disorders
• Psychiatry
• Youth

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MESH Headings

• Humans
• Adolescent
• Anxiety Disorders/epidemiology
• Anxiety Disorders/therapy
• Cannabis
• Cohort Studies
• Ontario/epidemiology
• Hospitalization
• Patient Acceptance of Health Care

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Affiliation(s)

André J McDonald Epidemiology Division, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Peter Boris Centre for Addictions Research, St. Joseph's Healthcare Hamilton, Hamilton, Ontario, Canada; Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada; Michael G. DeGroote Centre for Medicinal Cannabis Research, McMaster University, Hamilton, Ontario, Canada.
Paul Kurdyak Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada; ICES, Toronto, Ontario, Canada; Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
Jürgen Rehm Epidemiology Division, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, Ontario, Canada; Institute of Clinical Psychology and Psychotherapy, Technische Universität Dresden, Dresden, Germany; Department of Psychiatry and Psychotherapy, Centre for Interdisciplinary Addiction Research (ZIS), University Medical Centre Hamburg-Eppendorf, Hamburg, Germany; Institute of Medical Science, Temerty Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada; I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation
Michael Roerecke Epidemiology Division, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Institute for Mental Health Policy Research, Centre for Addiction and Mental Health, Toronto, Ontario, Canada
Susan J Bondy Epidemiology Division, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada

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Collaborators Collapse

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.

Cannabis Use Among Students in Grades 8, 10, and 12, by Sex - King County, Washington, 2008-2021

Cannabis use during adolescence is associated with poor outcomes, including cognitive impairment, cannabis use disorder, and impaired driving. To guide prevention and use reduction strategies, Public Health - Seattle & King County described recent trends in cannabis use by sex among King County, Washington students in grades 8, 10, and 12 and examined trends in sex-based differences. Data collected during seven 2008-2021 survey periods by the Healthy Youth Survey (administered by the Washington State Department of Health) and restricted to King County students in grades 8, 10, and 12 (range = 33,439-39,391 students per cycle) were analyzed. Prevalence estimates were generated and sex-based prevalence differences (PDs) in current use (≥1 day during the previous 30 days) and frequent use (≥6 days during the previous 30 days) were assessed. PD models used weighted generalized linear regression with an interaction between sex and survey year. During 2008-2021, cannabis use declined among both male and female students. During 2008-2014, cannabis use was higher among male students than among female students (e.g., PD in 2008 = 4.8%) and not significantly different during 2014-2016; however, in 2021, current-use prevalence was lower among male students than among female students for the first time (PD = -1.3%). Frequent-use prevalence was similar among males and females. By grade levels, the highest prevalence of both current and frequent cannabis use was observed among 12th grade students, followed by 10th and 8th graders. Sex-specific differences by grade mirrored overall patterns. Developing tailored interventions that consider potential differences in risk and protective factors by sex or gender identity could promote equity in youth (grades 8, 10, and 12) cannabis use reduction measures.

Legalization and retail availability of recreational marijuana and adolescent use in schools

Legalization of use and retail sales of recreational marijuana in U.S. states and the associated potential increase in access to marijuana and normalization of its use by adults could lead to increased use by adolescents. Studies have found that states with legal recreational marijuana have higher rates of adolescent use and frequency of use compared to states without legal use. We examined changes in student office discipline referrals (ODRs) for substance use offenses in Oregon middle and high schools before and after the legalization of recreational marijuana relative to comparison schools in other states. We found that rates of substance use related ODRs in middle schools increased by 0.14 per 100 students (30% of the mean) with legalization relative to comparison schools. This increase was moderated by the presence of a marijuana outlet within one mile of the school. We found no statistically discernible changes in high school ODRs. Marijuana use in adolescence has been linked to negative health and social consequences, including academic problems, mental health issues, and impaired driving. Potential adverse impact on adolescents and investments in school-based prevention programs could be important considerations for policymakers and public health officials when evaluating marijuana legalization.

The effect of marijuana use in adolescence on college and graduate degree attainment

We estimate the long-term effect of using marijuana in adolescence on college and graduate degree attainment measured approximately 20 years later. We rely on the first two waves (1994-1996) and the fifth wave (2016-2018) of the National Longitudinal Study of Adolescent to Adult Health and estimate instrumental variables models that exploit the network structure at the second degree by using marijuana use status of friends of friends who are not themselves friends of the respondent in order to instrument for the respondent's marijuana use. Our models also include school and grade fixed effects. Marijuana use in adolescence leads to a large reduction in the likelihood of college and graduate degree attainment by the time respondents are aged 33-43 years old.

Cannabis use disorder, suicide attempts, and self-harm among adolescents: A national inpatient study across the United States

BACKGROUND

Suicide is among the top three causes of adolescent mortality. There is a scarcity of research examining cannabis use and suicidal behavior in adolescents.

OBJECTIVES

To determine the association between cannabis use disorder (CUD) and suicide attempt/self-harm in a hospitalized sample of adolescents.

METHODS

We conducted a cross-sectional observation study using data from the Nationwide Inpatient Sample collected over four years from January 1, 2016, through December 31, 2019. We included adolescents aged 10-19 hospitalized during the above period (N = 807,105). The primary outcome was suicide attempt/self-harm and the main predictor was CUD. The International Classification of Diseases Tenth Revision (ICD 10) diagnostic codes was used to identify a diagnosis of CUD, suicide attempt/self-harm, and other diagnoses included in the analyses. Adolescents diagnosed with CUD (n = 53,751) were compared to adolescents without CUD (n = 753,354). Univariate and multivariate logistic regressions were conducted to determine the association between CUD and suicide attempts/self-harm.

RESULTS

807,105 adolescent hospitalizations were analyzed, of which 6.9% had CUD. Adolescents with CUD were more likely to be older (17 years vs. 15 years), female (52% vs. 48%), have depression (44% vs. 17%), anxiety (32% vs. 13%), an eating disorder (1.9% vs. 1.2%), ADHD (16.3% vs. 9.1%), Conduct Disorder (4.1% vs. 1.3%), Alcohol Use Disorder (11.9% vs. 0.8%), Nicotine Use Disorder (31.1% vs. 4.1%), Cocaine Use Disorder (5.4% vs. 0.2%), Stimulant Use Disorder (0.8% vs. 0.4%) and report suicide attempts/self-harm (2.8% vs. 0.9%) [all ps<0.001]. After adjusting for potential confounders, CUD was associated with a higher risk of suicide attempts/self-harm (OR = 1.4, 95% CI 1.3-1.6, p <0.001). Post-hoc analyses showed the presence of depression moderated the association between CUD and suicide attempts/self-harm in that adolescents with CUD and depression had 2.4 times the odds of suicide attempt/self-harm compared to those with CUD but no depression after controlling for potential confounders (p<0.001).

CONCLUSIONS

Our study provides evidence for the association between CUD and suicide risk among hospitalized adolescents and underscores the importance of recognizing and addressing co-occurring mental and substance use disorders along with CUD to mitigate suicide risk. Identifying high-risk adolescents in inpatient settings provides an opportunity for intervention.

Emerging adult perceptions of cannabis consumption: Examining changes in perceptions from pre-legalization to post-legalization

BACKGROUND

Emerging adults (EAs) have the highest rates of cannabis consumption in Canada and are vulnerable to the potential impacts of frequent cannabis consumption. This study assessed EAs' perceived risk of cannabis consumption across multiple domains of potential harm based on the age (14-year-old, 21-year-old, or 28-year-old) and sex (male or female) of the vignette character, time-point (pre- or post-legalization), and participant's gender.

METHODS

Secondary analyses were conducted on data from a pre-legalization study and post-legalization replication. Participants included EAs between 18 and 25 years of age and living in Newfoundland and Labrador. Participants from the pre- and post-legalization studies were matched based on demographic variables and the assigned vignette character. Participants responded to seven items of perceived risk based on their assigned vignette character's (varied by age or sex) almost daily cannabis consumption.

RESULTS

Participants (N = 689) viewed cannabis consumption to have greater risks for a 14-year-old compared to a 21- or 28-year-old in all domains except for social life. Prior to legalization, participants who identified as a woman felt that cannabis had more detrimental impacts on social life than participants who identified as a man. Findings also suggested that pre-legalization cannabis consumption by a female was perceived as more detrimental to their social life than pre-legalization consumption by a male and post-legalization consumption by a female.

CONCLUSION

EAs do not fully appreciate the risks of cannabis consumption, suggesting that it is imperative for public health strategies to promote increased awareness of the risks of frequent cannabis consumption, and improve cannabis health literacy in this population.

Testing the cannabis gateway hypothesis in a national sample of Spanish adolescents

BACKGROUND

The gateway hypothesis holds that the use of legal substances (i.e., tobacco and alcohol) increases the risk of initiating in cannabis use which, in turn, increases the chances of using other illegal substances. The validity of this hypothesis has been the subject of intense debate in recent years, finding sequences with a different order. Moreover, this pattern has been scarcely studied in Spain, where characteristics related to cannabis use are meaningfully different to other countries. This study aims to examine the gateway effects of cannabis towards other legal and illegal substances in Spanish adolescents.

MATERIAL AND METHODS

Data were obtained from the Ministry of Health in Spain, through a representative survey of addictive behaviors of 36,984 Spanish adolescents (M_age = 15.7, SD = 1.2, 51.4% females).

RESULTS

Lifetime cannabis use increased the likelihood of later legal substance use, both tobacco (OR = 2.0; 95%CI 1.81, 2.22) and alcohol (OR = 1.93; 95%CI 1.61, 2.31), as well as illegal substances (OR = 5.36; 95%CI 4.80, 5.98) and polysubstance (OR = 18.24; 95%CI 14.63, 22.73). Early age of cannabis use onset significantly increased the likelihood of subsequent legal and illegal substance use (ORs between 1.82 and 2.65).

CONCLUSIONS

These findings confirm and expand the available evidence on cannabis as a gateway substance. These results can help to drive preventive strategies for substance use in Spanish adolescents.

Avatar Intervention for Cannabis Use Disorder in Individuals with Severe Mental Disorders: A Pilot Study

Cannabis use disorder (CUD) is a complex issue, even more so when it is comorbid with a severe mental disorder (SMD). Available interventions are at best slightly effective, and their effects are not maintained over time. Therefore, the integration of virtual reality (VR) may increase efficacy; however, it has not yet been investigated in the treatment of CUD. A novel approach, avatar intervention for CUD, uses existing therapeutic techniques from other recommended therapies (e.g., cognitive behavioral methods, motivational interviewing) and allows participants to practice them in real-time. During immersive sessions, participants are invited to interact with an avatar representing a significant person related to their drug use. This pilot clinical trial aimed to evaluate the short-term efficacity of avatar intervention for CUD on 19 participants with a dual diagnosis of SMD and CUD. Results showed a significant moderate reduction in the quantity of cannabis use (Cohen's d = 0.611, p = 0.004), which was confirmed via urinary quantification of cannabis use. Overall, this unique intervention shows promising results. Longer-term results, as well as comparison with classical interventions in a larger sample, are warranted through a future single-blind randomized controlled trial.

Cannabis arteritis presenting with Raynaud's and digital ulcerations: a case-based review of a controversial thromboangiitis obliterans-like condition

Thromboangiitis obliterans (TAO), or Buerger's disease, is a non-atherosclerotic inflammatory disease of the small and medium-sized arteries, veins, and nerves of the legs and arms, strongly associated with the use of tobacco products in young adults. Cannabis arteritis (CA), an entity with similar clinical and pathological features, has been described in marijuana users as a subtype of TAO. Distinction between TAO and CA is challenging, given that most patients use tobacco and marijuana products concomitantly. Herein, we report the case of a male in his late forties who was referred to rheumatology with a 2-month history of hand swelling and bilateral painful digital ulcers with blue discoloration on his fingers and toes. The patient reported daily use of marijuana in blunt wraps and denied tobacco use. His laboratory work-up was negative for scleroderma and other connective tissue diseases. His angiogram confirmed the diagnosis of thromboangiitis obliterans, which was attributed to cannabis arteritis. The patient was started on aspirin and nifedipine daily and discontinued marijuana use. His symptoms resolved within 6 months and have not recurred for more than a year with continued avoidance of marijuana. Our case is one of the few that features primarily marijuana-driven CA and highlights the importance of not only considering marijuana use but also blunt wrap use in patients presenting with Raynaud's phenomenon and ulcerations as cannabis use rises globally.

Effect of cannabis smoke condensate on human nasal epithelial cell adhesion, growth, and migration

OBJECTIVE

When inhaled, cannabis smoke interacts with airway tissues, including the nasal mucosa, which may lead to nasal pathologies. We examined the effect of cannabis smoke condensate (CSC) on nasal epithelial cell and tissue behaviors.

METHODS

Human nasal epithelial cells were exposed or not to CSC at different concentrations (1, 5, 10, and 20 %) and for different durations. Cell adhesion and viability were assessed, as well as post-wound cell migration and lactate dehydrogenase (LDH) release.

RESULTS

The nasal epithelial cells showed a larger cell size and a faint nucleus following exposure to CSC, compared to that observed in that control. This was supported by fewer adherent cells present after exposure for either 1 or 24 h to 5, 15, and 20 % CSC. CSC also had a significant toxic effect by reducing cell viability after both 1 and 24 h of exposure. This toxic effect was significant even at a low concentration (1 %) of CSC. The effects on nasal epithelial cell viability were confirmed by the decrease in cell migration. After the scratch and subsequent exposure to CSC for either 6 or 24 h, a complete inhibition of nasal epithelial cell migration was observed, compared to that found in the controls. CSC was toxic to the nasal epithelial cells, as the level of LDH significantly increased following cell exposure all CSC concentrations.

CONCLUSION

Cannabis smoke condensate had a negative effect on several nasal epithelial cell behaviors. These findings indicate that cannabis smoke could be a threat to nasal tissues and ultimately lead to nasal and sinus disorders.

Effects of cannabis legalization on the use of cannabis and other substances

PURPOSE OF REVIEW

As more jurisdictions legalize cannabis for non-medical use, the evidence on how legalization policies affect cannabis use and the use of other substances remains inconclusive and contradictory. This review aims to summarize recent research findings on the impact of recreational cannabis legalization (RCL) on cannabis and other substance use among different population groups, such as youth and adults.

RECENT FINDINGS

Recent literature reports mixed findings regarding changes in the prevalence of cannabis use after the adoption of RCL. Most studies found no significant association between RCL and changes in cannabis use among youth in European countries, Uruguay, the US, and Canada. However, some studies have reported increases in cannabis use among youth and adults in the US and Canada, although these increases seem to predate RCL. Additionally, there has been a marked increase in unintentional pediatric ingestion of cannabis edibles postlegalization, and an association between RCL and increased alcohol, vaping, and e-cigarette use among adolescents and young adults.

SUMMARY

Overall, the effects of cannabis legalization on cannabis use appear to be mixed. Further monitoring and evaluation research is needed to provide longer-term evidence and a more comprehensive understanding of the effects of RCL.