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

Understanding youth and young adult cannabis use in Canada post-legalization: a scoping review on a public health issue

BACKGROUND

Canada legalized recreational cannabis in 2018, and one of the primary objectives of the Cannabis Act was to protect youth by reducing their access to cannabis and providing public education. Canada has the highest prevalence of cannabis use worldwide, particularly among youth and young adults under the age of 25. Cannabis use is linked with many adverse effects for youth and young adults including psychosis, anxiety, depression, respiratory distress, cannabinoid hyperemesis syndrome, and impaired cognitive performance. Despite the high prevalence of cannabis use and the evolution of policies in Canada and globally, significant knowledge and research gaps remain regarding youth and young adult cannabis use. The aim of this scoping review is to map the extent, nature, and range of evidence available on youth and young adult cannabis use in Canada since its legalization, in order to strengthen policies, services, treatments, training, and public education strategies.

METHODS

Using a scoping review framework developed by Arksey and O'Malley, along with the PRISMA-ScR guidelines, we conducted a rigorous search in five academic databases: MEDLINE, Embase, APA PsycINFO, CINAHL and Web of Science Core Collection. We included empirical studies that collected data in Canada after the legalization of recreational cannabis (October 2018) and focused on youth or young adults < 30. Two reviewers independently screened articles in two stages and extracted relevant information from articles meeting the inclusion criteria.

RESULTS

Of the 47 articles meeting our inclusion criteria, 92% used quantitative methods, 6% were qualitative, and 2% used a mixed-methods approach. Over two-thirds (68%) used secondary data. These studies were categorized into six focus areas: (1) prevalence, patterns, and trends, (2) cannabis-related injuries and emergency department (ED) visits, (3) rates and patterns during the pandemic, (4) perceptions of cannabis use, (5) prevention tools, and (6) cannabis-related offenses. Key findings from the studies reviewed include an increase in cannabis use among 18-24-year-olds post-legalization, with mixed results for youth under 18. ED visits for intentional and unintentional cannabis-related injuries have increased in young children and teens. Perception studies show a mix of concern and normalization of cannabis use. Though limited, prevention studies are promising in raising awareness. A decline in cannabis-related offenses was noted by one study. The review highlights several research gaps, including the need for more qualitative data, disaggregation of demographic data, intervention research, and comprehensive studies on the physical and mental health impacts of cannabis use among youth and young adults.

CONCLUSION

Maintaining a public health approach is critical, with a focus on reducing the high prevalence of cannabis use among youth and young adults. This involves implementing prevention strategies to minimize harms, enhancing public education, minimizing commercialization, reducing youth access to cannabis, promoting guidelines for lower-risk cannabis use and harm reduction strategies, and increasing training for healthcare providers.

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.

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.

Social Anxiety and Cannabis-Related Problems: The Serial Roles of Distress Tolerance and Cannabis Use Motives

Background: Individuals with elevated social anxiety are vulnerable to experiencing negative consequences related to cannabis use. One transdiagnostic vulnerability factor that has received little attention in the social anxiety-cannabis problem relation is distress tolerance, which is associated with more cannabis use to manage negative affect broadly (i.e., coping motives) and cannabis-related problems. However, it is unknown whether distress tolerance is related to greater cannabis use to manage social anxiety specifically (i.e., social anxiety motives). Objectives: This study tested whether the relation between social anxiety and cannabis problems occurred via perceived distress tolerance among 309 (77.3% female) undergraduates who endorsed current (past three-month) cannabis use. Results: Social anxiety was negatively associated with distress tolerance and positively associated with cannabis problems, coping, and social anxiety motives. Social anxiety was indirectly (via distress tolerance) related to more cannabis problems and motives to cope with negative affect generally and to cope with social anxiety specifically. Social anxiety was indirectly related to more cannabis problems via the serial effects of distress tolerance and coping and social anxiety motives. Conclusions: Findings suggest that individuals with elevated social anxiety may be vulnerable to using cannabis to manage negative affect (generally and social anxiety specifically) due to low perceived ability to tolerate psychological distress, which may lead to more cannabis problems. Keywords: cannabis; marijuana; distress tolerance; social anxiety; motives; coping motives.

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.

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.

Examining the effect of cannabis cues on cannabis demand in sleep, driving, and typical drug-use contexts

PURPOSE

Given the expanding legal cannabis market in the U.S., it is vital to understand how context impacts cannabis use. Therefore, we explored the effect of cannabis cues and cannabis-use context on cannabis demand in 79 adults who reported smoking cannabis at least weekly.

METHODS

Participants completed a single laboratory session consisting of four hypothetical marijuana purchase tasks (MPTs) involving either a typical use situation or a driving or sleep context. The MPTs were alternated with exposure to cannabis or neutral picture cues based on block randomization by gender.

RESULTS

Cannabis cues increased self-reported craving for cannabis (p =.044) but did not significantly alter demand (ps =0.093-0.845). In the driving context, participants demonstrated a significant reduction in cannabis demand, indicated by lower intensity (p <0.001), Omax (p <0.001), and Pmax (p <0.001), breakpoint (p =.003), and higher α (p <0.001). The sleep context was associated with significantly greater α (p <0.006) but nonsignificant effects for other indices (ps =0.123-0.707). Finally, cannabis cues increased Omax (p =.013) and breakpoint (p =.035) in the sleep context but not in the typical-use context.

CONCLUSIONS

These findings suggest that cannabis-use behavior is sensitive to contingencies surrounding driving after cannabis use and may also be sensitive to sleep contexts in the presence of cannabis cues. Since this is the first study to examine driving and sleep contexts, we caution against drawing broad conclusions until future research is conducted to replicate these findings.

Cannabis to cope with COVID-19 in college

Objective: Cannabis use in college students has increased over time and is linked to negative consequences. During the COVID-19 pandemic, many students experienced greater stress, which could heighten cannabis use and related consequences. This study was designed to clarify motivations for cannabis use that may link pandemic-related stressors to time spent high and cannabis-related consequences.Participants: A total of 488 cannabis-using college students (75% women) participated.Methods: A cross-sectional survey was administered in Fall 2020 and Spring 2021 to examine students' experiences during the pandemic.Results: Indirect effects revealed that pandemic-related social stressors were linked to coping and boredom motives, and in turn, more hours spent high and cannabis-related consequences. Similarly, pandemic-related distress was associated with more coping motives and in turn, more hours spent high and cannabis-related consequences.Conclusions: Findings suggest prevention and intervention efforts may benefit from emphasizing alternative coping methods, including enhanced social support, during prolonged stressors.

Implementation and Preliminary Evaluation of a 12-Week Cognitive Behavioural and Motivational Enhancement Group Therapy for Cannabis Use Disorder

Background

The purpose of this paper is to provide a preliminary evaluation of treatment outcomes, retention and client satisfaction following a 12-week combined cognitive behavioural therapy (CBT) and motivational enhancement therapy (MET) group treatment for cannabis use disorder (CUD) delivered in an outpatient setting. Implementation of the program is also described.

Methods

A retrospective observational cohort study was conducted using data collected from medical records and self-report assessments. Participants were treatment-seeking cannabis users at the Centre for Addiction and Mental Health, Toronto. Cannabis use, cannabis-related problems, craving, withdrawal symptoms, self-efficacy for remaining abstinent, depression and anxiety were assessed pre- and post-treatment. Treatment retention was calculated by inspecting clinic attendance records, and client satisfaction was evaluated using an anonymous feedback survey. Potential predictors of treatment outcomes and retention were investigated in exploratory analyses.

Results

Cannabis use was lower and days of abstinence higher post-treatment (vs pre-treatment). Post-treatment improvements in cannabis-related problems, craving, withdrawal symptoms, self-efficacy and mood were also observed. Completion of group treatment (⩾75% of sessions attended) was 57% and moderate levels of treatment satisfaction were reported.

Conclusions

This study provides preliminary evidence that a 12-week combined CBT and MET treatment for cannabis use disorder delivered in a novel group setting improves cannabis use outcomes. Potential predictors of reduced cannabis use and retention were identified. Future controlled studies are warranted, and strategies for increasing retention should be explored.

Theory-based correlates of cannabis use and intentions among US and Israeli adults: a mixed methods study

BACKGROUND

In the US and Israel, non-medical ('recreational') cannabis use is illegal at the national level; however, use rates are high and decriminalization and legalization is spreading. Thus, theory-based intervention efforts, especially for youth prevention, are crucial.

METHODS

This mixed-methods study of adults in the US (n = 1,128) and Israel (n = 1,094) analyzed: 1) cross-sectional survey data (Fall 2021) to identify theory-based correlates (risk perceptions, social norms) of past-month cannabis use, next-year use intentions, and intentions to use in the home or among children if non-medical cannabis was legal, using multivariable regression; and 2) qualitative interviews regarding perceptions of cannabis policies and use (US n = 40, Israel n = 44).

RESULTS

16.7% reported past-month use; 70.5%, 56.3%, and 82.6% indicated "not at all likely" regarding next-year use and use in the home and among children if legal. Lower perceived risk and greater social norms were associated with past-month use, greater use intentions, and greater intentions to use in the home or among children. Past-month use was more prevalent among US (vs. Israeli) participants (22.0% vs. 11.2%); however, in multivariable regression controlling for past-month use, being from Israel was associated with greater use intentions (next-year; in the home/among children). Qualitative themes indicated: concerns about use (e.g., increasing use, health risks, driving-related risks) and legalization (e.g., impact on society/economy, marketing), and perceived benefits of use (e.g., medical) and legalization (e.g., access/safety, economic, individual rights).

CONCLUSIONS

Despite differences in cannabis perceptions and use across countries, perceived risk and social norms are relevant intervention targets regardless of sociopolitical context.

Impact of Canada's cannabis legalisation on youth emergency department visits for cannabis-related disorders and poisoning in Ontario and Alberta, 2015-2019

INTRODUCTION

Although there is momentum towards legalising adult recreational cannabis use worldwide, the extent of youth cannabis-related harm associated with legalisation is still uncertain. The current study aimed to assess whether the initial implementation of Canada's cannabis legalisation (via the Cannabis Act) on 17 October 2018 might be associated with youth harm, as assessed by emergency department visits for cannabis-related disorders/poisoning.

METHODS

We used Ontario and Alberta, Canada emergency department data from 1 April 2015 to 31 December 2019. We identified all cannabis-related disorders/poisoning (ICD-10 CA: F12.X, T40.7) emergency department visits of youth (n = 13,615), defined as patients younger than the minimum legal cannabis sales age (18 years, Alberta; 19 years, Ontario). Seasonal Autoregressive Integrated Moving Average (SARIMA) models were employed to assess the impact of legalisation on weekly counts of cannabis-related harms.

RESULTS

The final SARIMA intervention (step) parameter indicated a post-legalisation increase of 14.7 (95% confidence interval [CI] 5.0; 24.3, p < 0.01) weekly youth cannabis-related disorder/poisoning presentations to Ontario/Alberta emergency department settings, equivalent to an increase of 20.0% (95% CI 6.2%; 33.9%). There was no evidence of associations between cannabis legalisation and comparison series of youth alcohol, opioid or appendicitis emergency department episodes.

DISCUSSION/CONCLUSION

Our findings require replication and extension but are consistent with the possibility that the implementation of the Cannabis Act was associated with an increase in youth cannabis-related presentations to Ontario/Alberta emergency departments.

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

OBJECTIVE

Understanding how recreational cannabis legalization may impact cannabis use disorder (CUD) among adolescents and young adults is key to developing an appropriate public health response. This research investigates whether associations among adolescent and young adult perception of risk of harm from cannabis use, prevalence of past-month cannabis use, and rate of CUD treatment admissions changed following recreational cannabis legalization in the US, 2008-2019.

METHODS

Data from the NSDUH and TEDS-A datasets are employed in difference-in-differences models of the effect of recreational legalization on perception of risk, cannabis use prevalence, and CUD treatment admissions. Moderated models test whether associations among variables changed following recreational legalization.

RESULTS

Following recreational legalization: 1) adolescent and young adult past-month cannabis use prevalence increased; 2) among both adolescents and young adults, the association of lower perception of risk of harm with higher cannabis use prevalence was strengthened; 3) among adolescents, the association of higher cannabis use prevalence with higher CUD treatment admissions was suppressed; and 4) among young adults, an association of higher cannabis use prevalence with lower CUD treatment admissions emerged.

CONCLUSIONS

Recreational legalization is likely to increase cannabis use among adolescents and young adults who perceive cannabis as less harmful, while at the same time reduce rates of CUD treatment utilization. These trends portend an increase in unmet need for CUD treatment for age groups particularly vulnerable to the development and negative consequences of CUD.

The international regime of drug control may violate the human right to life and security

Critics of the international regime of drug control have often pointed to its criminogenic effects, maintaining that drug criminalization gives rise to a profitable illicit drugs market which in turn sustains organized crime networks. Here I will expand upon this critique to argue that the violent crime resulting from the drug criminalization regime may constitute a violation of the human right to life and security. To support this argument, I will discuss the extent to which policy makers and the citizens who empower them may stand morally responsible for unintended but foreseeable consequences of the policies they implement. I will note that a north-south imbalance is at play: while the Global North has been the driving force behind the criminalization regime, the violent criminality entailed by the regime of drug control has impacted the Global South most strongly.

Developments and Changes in Primary Public Health Outcome Indicators Associated with the Legalization of Non-Medical Cannabis Use and Supply in Canada (2018): A Comprehensive Overview

Canada legalized non-medical cannabis use and supply for adults in 2018. We examined developments and changes associated with the legalization policy reform on key indicators for public health, namely cannabis (including frequent/problematic) use prevalence, cannabis-related hospitalizations, cannabis-impaired driving, and cannabis sourcing. We identified peer-reviewed and "grey" study data that featured population-level or other quasi-representative samples and comparable outcome data for pre- and post-legalization periods, including possible trends of changes over time. Cannabis use has increased in select population groups, with use modes shifting away from smoking. Evidence on cannabis-related hospitalizations (e.g., for mental health) is mixed. The prevalence of cannabis-impaired driving appears to be generally steady but THC exposure among crash-involved drivers may have increased. Increasing proportions of users obtain cannabis products from legal sources but some-especially regular-users continue to use illicit sources. Overall, data suggest a mixed and inconclusive picture on cannabis legalization's impacts on essential public health indicators, including select extensions in trends from pre-legalization.