Recreational Marijuana Legalization and Adolescent Use of Marijuana, Tobacco, and Alcohol

The Impact of Medicaid Institutions for Mental Disease Exclusion Waivers on the Availability of Substance Abuse Treatment Services and the Varying Effect by Ownership Type

Policy Points The adoption of Medicaid institutions for mental disease (IMD) exclusion waivers increases the likelihood of substance abuse treatment facilities offering mental health and substance abuse treatment for co-occurring disorders, especially in residential facilities. There are differential responses to IMD waivers based on facility ownership. For-profit substance abuse treatment facilities are responsive to the adoption of IMD substance use disorder waivers, whereas private not-for-profit and public entities are not. The response of for-profit facilities suggests that integration of substance abuse and mental health treatment for individuals in residential facilities may be cost-effective.

CONTEXT

Access to integrated care for those with co-occurring mental health (MH) and substance use disorders (SUDs) has been limited because of an exclusion in Medicaid on paying for SUD care for those in institutions for mental disease (IMDs). Starting in 2015, the federal government encouraged states to pursue waivers of this exclusion, and by the end of 2020, 28 states had done so. It is unclear what impact these waivers have had on the availability of care for co-occurring disorders and the characteristics of any facilities that expanded care because of them.

METHODS

Using data from the National Survey of Substance Abuse Treatment Services, we estimate a two-stage residual inclusion model including time- and state-fixed effects to examine the effect of state IMD SUD waivers on the percentage of facilities offering co-occurring MH and SUD treatment, overall and for residential facilities specifically. Separate analyses are conducted by facility ownership type.

FINDINGS

Results show that the adoption of an IMD SUD waiver is associated with 1.068 greater odds of that state having facilities offering co-occurring MH and substance abuse (SA) treatment a year or more later. The adoption of a waiver increases the odds of a state's residential treatment facility offering co-occurring MH and SA treatment by 1.129 a year or more later. Additionally, the results suggest 1.163 higher odds of offering co-occurring MH/SA treatment in private for-profit SA facilities in states that adopt an IMD SUD waiver while suggesting no significant impact on offered services by private not-for-profit or public facilities.

CONCLUSIONS

Our study findings suggest that Medicaid IMD waivers are at least somewhat effective at impacting the population targeted by the policy. Importantly, we find that there are differential responses to these IMD waivers based on facility ownership, providing new evidence for the literature on the role of ownership in the provision of health care.

Recreational Cannabis Legalization, Retail Sales, and Adolescent Substance Use Through 2021

This cross-sectional study using survey datasets evaluates recreational cannabis legalization and retail sales policies and adolescent substance use through 2021.

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.

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

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

Youth Exposure to Recreational Cannabis Legalization: Moderation of Effects by Sex and Parental Cannabis Use during Adolescence

OBJECTIVE

Few studies of recreational cannabis legalization (RCL) have assessed adolescents both before and after RCL or considered moderators of RCL effects. The present study tested whether RCL was more strongly associated with cannabis use for girls and among youth whose parents had a history of cannabis use during adolescence.

METHOD

Data were pooled from 940 adolescents from three intergenerational studies that began in Washington (where RCL was enacted in 2012), Oregon (RCL year = 2015), and New York (RCL year = 2021). Youth were assessed repeatedly from ages 13 to 18 years (k = 3,650 person-years) from 1999 to 2020 (prior to RCL in New York). Parent cannabis use at or before age 18 years (yes/no) was assessed prospectively during the parent's adolescence. Multilevel models focused on the between-subjects effects of years of youth exposure to RCL on adolescents' mean cannabis use likelihood, and interactions with child sex and parent use history.

RESULTS

Child exposure to RCL was associated with a higher likelihood of cannabis use if their parents had a history of adolescent use, (Estimate [SE] = 0.67 [0.25], p = 0.008), versus no such history (Estimate [SE] = -0.05 [0.28], p = 0.855). RCL effects were not moderated by child sex.

CONCLUSIONS

The effects of RCL on adolescents' cannabis use may depend on their parents' history of using the drug. Identifying other moderators of RCL effects, and understanding the mechanisms of these risks and the ways that parents and communities can offset them, are prevention priorities.

Cannabis Policy and Consumption: Taking into account Substitution Effects

Background: Previous studies examining the cannabis-alcohol substitution effect have found that medical cannabis policies may result in substituting the use of cannabis in place of alcohol use. Objectives: This study adds to the literature on cannabis-alcohol substitution by analyzing the effect of decriminalization, medicinal cannabis, and adult-use legalization cannabis policies (2002-2019) on cannabis and alcohol use and substance substitution for all 50 states and the District of Columbia (N=867). Results: Results support the notion that liberalized cannabis policies can increase the prevalence of cannabis use. An adult-use legalization specific analysis yielded findings suggesting a complex and heterogenous effect of such laws on cannabis-alcohol complementation. Conclusion: Given the lack of clarity and heterogenous effects of cannabis laws, policy makers should carefully take into consideration the benefits of medical cannabis laws, along with the risks of decriminalization and adult-use legalization.

Pre-Post Cannabis Legalization for Adult Use: A Trend Study of Two Cohorts of Young Adult Cannabis Users in Los Angeles

Cannabis was legalized for adult use in California in 2016 for individuals 21 and older. Among 18-20-years-olds, who can possess cannabis legally as medical cannabis patients (MCP) but not as non-patient cannabis users (NPU), the impact of adult use legalization (AUL) on cannabis and other substance use is unknown. Two cohorts of 18-20-year-old cannabis users (MCP and NPU) were surveyed, one in 2014-15 (n = 172 "pre-AUL") and another in 2019-20 (n = 139 "post-AUL"), using similar data collection methods in Los Angeles, California. Logistic and negative binomial regressions estimated cohort and MCP differences for cannabis and other drug use outcomes based on past 90-day use. In both pre- and post-AUL cohorts, MCP were more likely to self-report medical cannabis use (p < .001) while the post-AUL cohort reported greater use of edibles (p < .01), but fewer mean days of alcohol (p < .05) and cigarette (p < .01) use in multivariate models. Notably, frequency of cannabis use (days or hits per day) did not significantly differ between the pre- and post-AUL cohorts, except for greater use of edibles, despite potentially greater access to cannabis.

Recreational Cannabis Legalization and Proximity to Cannabis Retailers as Risk Factors for Adolescents' Cannabis Use

Within-person studies are lacking regarding how recreational cannabis legalization (RCL) and the numbers of neighborhood cannabis retailers relate to adolescents' cannabis use. Study participants were 146 offspring (55% girls; 77% White non-Latinx) of men recruited in childhood from neighborhoods with high delinquency rates. Youth were assessed for past-year cannabis and alcohol use one or more times from ages 13 to 20 years (age M[SD] = 16.4 [2.1] years across 422 observations), while they were living in Oregon or Washington from 2005 to 2019 (where cannabis retail stores opened to adults ages 21 years and older in 2014 and 2015, respectively). We calculated distances between addresses of licensed cannabis retailers and participants' homes. Multilevel models that accounted for effects of age on cannabis use did not support that the number of retail stores within 2-, 5-, 10-, or 20-mile radii of adolescents' homes increased likelihood of past-year cannabis use at the within- or between-subjects levels. Likewise, primary models did not support a greater likelihood of cannabis use among youth whose adolescence coincided more fully with the post-RCL period. A secondary model suggested that after adjusting for adolescents' concurrent alcohol use as a marker of general substance use risk, RCL was associated with cannabis use (between-subjects B [95% CI] = .35 [.05-.66], p = .024). Further research is needed with larger prospective samples, at-risk subgroups, and as cannabis markets mature.

Recreational cannabis legislation and binge drinking in U.S. adolescents and adults

BACKGROUND

Recreational cannabis laws (RCLs) may have spillover effects on binge drinking. Our aims were to investigate binge drinking time trends and the association between RCLs and changes in binge drinking in the United States (U.S.).

METHODS

We used restricted National Survey on Drug Use and Health data (2008-2019). We examined trends in the prevalence of past-month binge drinking by age groups (12-20, 21-30, 31-40, 41-50, 51+). Then, we compared model-based prevalences of past-month binge drinking before and after RCL by age group, using multi-level logistic regression with state random intercepts, an RCL by age group interaction term, and controlling for state alcohol policies.

RESULTS

Binge drinking declined overall from 2008 to 2019 among people aged 12-20 (17.54% to 11.08%), and those aged 21-30 (43.66% to 40.22%). However, binge drinking increased among people aged 31+ (ages 31-40: 28.11% to 33.34%, ages 41-50: 25.48% to 28.32%, ages 51+: 13.28% to 16.75%). When investigating model-based prevalences after versus before RCL, binge drinking decreased among people aged 12-20 (prevalence difference=-4.8%; adjusted odds ratio (aOR)=0.77, [95% confidence interval (CI) 0.70-0.85]), and increased among participants aged 31-40 (+1.7%; 1.09[1.01-1.26]), 41-50 (+2.5; 1.15[1.05-1.26]) and 51+ (+1.8%; 1.17[1.06-1.30]). No RCL-related changes were noted in respondents ages 21-30.

CONCLUSIONS

Implementation of RCLs was associated with increased past-month binge drinking in adults aged 31+ and decreased past-month binge drinking in those aged < 21. As the cannabis legislative landscape continues to change in the U.S., efforts to minimize harms related to binge drinking are critical.

The Association Between Cannabis Use and Subsequent Nicotine Electronic Cigarette Use Among US Adolescents

PURPOSE

The current study assessed the association between cannabis use among youth never e-cigarette users and subsequent e-cigarette use.

METHODS

The Population Assessment of Tobacco and Health Study is a nationally representative cohort study. Participants aged 12 years and older were selected using a 4-stage, stratified probability sample design from the US civilian, noninstitutionalized population. We included adolescents who participated in both wave 4.5 (2017-2018) and wave 5 (2018-2019) of Population Assessment of Tobacco and Health, and were never e-cigarette users at baseline (N = 9,925). Through multivariable logistic regressions, we examined the prospective association between cannabis use and subsequent e-cigarette use.

RESULTS

E-cigarette use at wave five was significantly more common among youth cannabis users at wave 4.5. The adjusted relative risks between ever cannabis use and subsequent past 12-month, past 30-day, and frequent e-cigarette use (≥20 days per month) were 1.53 (95% CI, 1.26-1.81), 1.70 (95% CI, 1.25-2.15), and 2.10 (95% CI, 1.17-3.03), respectively. The adjusted relative risks between past 30-day cannabis use and subsequent past 12-month, past 30-day, and frequent e-cigarette use were 1.54 (95% CI, 1.04-2.28), 2.01 (95% CI, 1.23-3.29), and 2.87 (95% CI, 1.44-5.71), respectively. We also found significant associations between ever cannabis vaping with subsequent e-cigarette use.

DISCUSSION

While previous research associates e-cigarette use with subsequent onset of cannabis use, we identify a reverse directional effect, where adolescent cannabis use is associated with increased likelihood of future e-cigarette use.

Risk Factors for Adolescent Cannabis Use in a State With Legal Recreational Cannabis: The Role of Parents, Siblings, and Friends

PURPOSE

Cannabis use during adolescence can have harmful consequences, including poor educational outcomes, neurocognitive defects, and an increased risk of addiction to other drugs, such as tobacco, alcohol, and opioids. Perceived family and social network cannabis use is a risk factor for use among adolescents. It is not currently known whether there is an association between perceived family/social network cannabis use and adolescent cannabis use in the context of legalization. The purpose of this study was to examine associations between adolescent perceptions of parent, sibling, and best friend medical and/or recreational cannabis use and adolescents' own use and whether the association changed pre-legalization and post-legalization in Massachusetts.

METHODS

We analyzed responses from surveys administered to students at 2 high schools in Massachusetts before legalization in 2016 (wave 1) and after legalization but before the start of regulated retail cannabis sales in 2018 (wave 2). We used χ2 tests and multiple logistic regression to examine associations between adolescent perception of parent, sibling, and best friend use and adolescent past 30-day cannabis use before and after legalization.

FINDINGS

In this sample, no statistically significant differences were found in the prevalence of past 30-day cannabis use before and after legalization among adolescents. There was an increase in the proportion of adolescents who reported any perceived parent cannabis use from before to after legalization (18% before legalization to 24% after legalization; P = 0.018). Perceived parent, sibling, and best friend medical and recreational cannabis use were all associated with an increased odds of adolescent use, with the highest increase in odds found for perceived best friend use (adjusted odds ratio, 17.2; 95% CI, 12.4-24.0).

IMPLICATIONS

Adolescent perceptions of their parents as cannabis users increased after legalization, even before state-regulated retails sales began. Parent, sibling, and best friend cannabis use is each independently associated with increased odds of adolescent's own use. These findings from 1 Massachusetts district should be explored in larger and more representative populations and motivate additional attention to interventions that consider family and friend influences when seeking to address adolescent cannabis use.

The Impact of Cannabis Use on Adolescent Neurodevelopment and Clinical Outcomes Amidst Changing State Policies

Cannabis is the most common illicit substance used by adolescents and the third most common psychoactive substance after alcohol and nicotine. Cannabis use during adolescence interrupts a critical period of brain development and leads to inappropriate activation of the reward pathway. Because the prefrontal cortex, which is responsible for impulse control and other executive functions, is not fully mature until the mid-twenties, the adolescent brain is especially vulnerable to damage from substance use. Although cannabis remains illegal at the federal level, recent changes in state policies have been associated with increased availability of a wide variety of cannabis products. As new products, formulations, and delivery devices that can deliver higher and faster peak doses of tetrahydrocannabinol enter the market, there is an even greater potential for cannabis to have negative clinical impacts on adolescent health. This article reviews the current literature on the impact of cannabis on adolescent health, including the neurobiology of the adolescent brain, potential clinical outcomes in adolescents who use cannabis, and the effects of changing state policies regarding cannabis on the increased availability of unregulated products.

Cannabis Recreational Legalization and Prevalence of Simultaneous Cannabis and Alcohol Use in the United States

BACKGROUND

Simultaneous cannabis/alcohol use, using both substances within a short time interval so that their effects overlap, has a greater risk of potential negative consequences than single-substance use and is more common in younger age. Relationships between recreational cannabis laws (RCLs) and changes in simultaneous cannabis/alcohol use prevalence remain untested.

OBJECTIVE

To examine trends in simultaneous cannabis/alcohol use from 2008 to 2019, and investigate associations between implementation of RCLs (i.e., presence of active legal dispensaries or legal home cultivation) and simultaneous cannabis/alcohol use in the United States (U.S.).

DESIGN

Repeated cross-sectional samples from the 2008-2019 U.S. National Survey on Drug Use and Health (NSDUH).

PARTICIPANTS

Respondents (51% female) aged 12 and older.

INTERVENTIONS

Changes in simultaneous cannabis/alcohol use before and after RCL implementation (controlling for medical cannabis law implementation) were compared in different age groups (12-20, 21-30, 31-40, 41-50, 51+), using adjusted multi-level logistic regression with state random intercepts and an RCL/age group interaction.

MEASUREMENTS

Self-reported simultaneous cannabis/alcohol use.

RESULTS

From 2008 to 2019, the overall prevalence of simultaneous cannabis/alcohol use declined among those aged 12-20 but increased in adults aged 21+. Model-based simultaneous cannabis/alcohol use prevalence increased after RCL implementation among respondents aged 21-30 years (+1.2%; aOR= 1.15 [95%CI = 1.04-1.27]), 31-40 years (+1.0; 1.15 [1.04-1.27]), and 41-50 years (+1.75; 1.63 [1.34-1.98]), but not in individuals aged <21 or 51+ years.

CONCLUSIONS

Implementation of recreational cannabis policies resulted in increased simultaneous use of cannabis and alcohol, supporting the complementarity hypothesis, but only among adults aged 21+. Efforts to minimize harms related to simultaneous cannabis/alcohol use are critical, especially in states with RCLs. Future studies should investigate cultural norms, perceived harm, and motives related to simultaneous use.

Assessing the Impact of Recreational Cannabis Legalization on Cannabis Use Disorder and Admissions to Treatment in the United States

Purpose of Review

Policy implications from changes in recreational cannabis laws (RCLs) have raised public health concerns. While numerous studies have examined the impact of RCLs on cannabis use, there is less research on the risk of developing cannabis use disorder (CUD). This review summarizes the latest research on the effects of RCLs on CUD prevalence and cannabis treatment admissions.

Recent Findings

Nine studies were published between 2016 - 2022 that examined RCLs and CUD or treatment. Findings generally indicate an increase in CUD prevalence associated with legalization, but effects differ by age group. There was no significant association between legalization and CUD treatment admissions, and CUD admissions decreased overall during the study periods.

Summary

To improve policy, prevention, and treatment services, policymakers should monitor RCLs' effects on adverse public health outcomes and researchers should consider the effects on individual and community-level characteristics. We discuss methodological challenges in conducting state-level research and provide suggestions for future studies.

Have recreational marijuana laws undermined public health progress on adult tobacco use?

Public health experts caution that legalization of recreational marijuana may normalize smoking and undermine the decades-long achievements of tobacco control policy. However, very little is known about the impact of recreational marijuana laws (RMLs) on adult tobacco use. Using newly available data from the Population Assessment of Tobacco and Health (PATH) and dynamic difference-in-differences and discrete-time hazard approaches, we find that RML adoption increases prior-month marijuana use among adults ages 18-and-older by 2-percentage-points, driven by an increase in marijuana initiation among prior non-users. However, this increase in adult marijuana use does not extend to tobacco use. Rather, we find that RML adoption is associated with a lagged reduction in electronic nicotine delivery systems (ENDS) use, consistent with the hypothesis that ENDS and marijuana are substitutes. Moreover, auxiliary analyses from the National Survey on Drug Use and Health (NSDUH) show that RML adoption is associated with a reduction in adult cigarette smoking. We conclude that RMLs may generate tobacco-related health benefits.

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.

Impacts of recreational cannabis legalization on use and harms: A narrative review of sex/gender differences

Legalization of cannabis use for non-medical (recreational) purposes is changing the global cannabis landscape. As attitudes toward cannabis use become more positive and prevalence of use increases in complex ways, concerns emerge about the potential for increased cannabis-attributable harms. Understanding the who, why, and when of this likely increase in cannabis-attributable harms is thus an important public health priority. Both sex and gender contribute to variability in the use, effects, and harms of cannabis and thus sex/gender considerations are important when evaluating the impacts of cannabis legalization. The goal of this narrative review is to broadly discuss sex/gender differences in attitudes toward and prevalence of cannabis use, whether there are sex/gender differences in the impacts of cannabis legalization, and why these sex/gender differences might exist. One of our strongest conclusions is that men have always been more likely to use cannabis than women, yet the sex/gender gap in prevalence of cannabis use has narrowed over time, and this might be partly due to cannabis legalization. The existing evidence suggests that there have also been sex/gender differences in the impacts of legalization on cannabis-attributable harms such as cannabis-involved motor vehicle collisions and hospitalizations, though these results are more variable. The body of literature reviewed has focused almost exclusively on samples of cisgender research participants, and thus future research should encourage inclusion of transgender and gender-diverse participants. More consideration of sex- and gender-based analysis in research evaluating long-term impacts of cannabis legalization is a clear research priority.

The Role of Cigarillo Flavor in the Co-Use of Cigarillos and Cannabis among Young Adults

Background: Research suggests flavor facilitates cigarillo use, but it is unknown if flavor impacts patterns of co-use of cigarillos and cannabis ("co-use"), which is common among young adult smokers. This study's aim was to determine the role of the cigarillo flavor in co-use among young adults. Methods: Data were collected (2020-2021) in a cross-sectional online survey administered to young adults who smoked ≥2 cigarillos/week (N = 361), recruited from 15 urban areas in the United States. A structural equation model was used to assess the relationship between flavored cigarillo use and past 30-day cannabis use (flavored cigarillo perceived appeal and harm as parallel mediators), including several social-contextual covariates (e.g., flavor and cannabis policies). Results: Most participants reported usually using flavored cigarillos (81.8%) and cannabis use in the past 30 days ("co-use") (64.1%). Flavored cigarillo use was not directly associated with co-use (p = 0.90). Perceived cigarillo harm (β = 0.18, 95% CI = 0.06, 0.29), number of tobacco users in the household (β = 0.22, 95% CI = 0.10, 0.33), and past 30-day use of other tobacco products (β = 0.23, 95% CI = 0.15, 0.32) were significantly positively associated with co-use. Living in an area with a ban on flavored cigarillos was significantly negatively associated with co-use (β = -0.12, 95% CI = -0.21, -0.02). Conclusions: Use of flavored cigarillos was not associated with co-use; however, exposure to a flavored cigarillo ban was negatively associated with co-use. Cigar product flavor bans may reduce co-use among young adults or have a neutral impact. Further research is needed to explore the interaction between tobacco and cannabis policy and use of these products.

The impact of recreational cannabis markets on motor vehicle accident, suicide, and opioid overdose fatalities

In the U.S., an increasing number of states are legalizing regulated commercial markets for recreational cannabis, which allows private industry to produce, distribute, and sell marijuana to those 21 and older. The health impacts of these markets are not fully understood. Preliminary evidence suggests recreational markets may be associated with increased use among adults, which indicates there may be downstream health impacts on outcomes related to cannabis use. Three causes of death that are linked to cannabis use are motor vehicle accidents, suicide, and opioid overdose. Drawing on data from U.S. death certificates from 2009 to 2019, we conducted a difference-in-differences analysis to estimate the impact of recreational markets on fatalities from motor vehicle accidents, suicide, and opioid overdose in seven states: Colorado, Washington, Oregon, Alaska, Nevada, California, and Massachusetts. States with comprehensive medical cannabis programs with similar pre-trends in deaths were used as comparisons. For each outcome, a pooled estimate was generated with a meta-analysis using random effects models. The results revealed substantial increases in crash fatalities in Colorado, Oregon, Alaska, and California of 16%, 22%, 20%, and 14%, respectively. Based on estimates from all seven states, recreational markets were associated with a 10% increase in motor vehicle accident deaths, on average. This study found no evidence that recreational markets impacted suicides. Most states saw a relative reduction in opioid overdose death that ranged between 3 and 28%. On average, recreational markets were associated with an 11% reduction in opioid overdose fatalities.

Behavioral economic relationship between cannabis and cigarettes: Evidence from hypothetical purchase tasks

BACKGROUND

In the United States (U.S), cannabis policies have been increasingly liberalized whereas tobacco policies have been increasingly stringent. Given the high prevalence of cannabis and tobacco dual use, there are concerns that a policy regulating one substance may unintendedly influence the other. This study examined the responsiveness of the demand for cannabis joints and cigarettes when price varied.

METHODS

The study included 338 adult participants (21+) who used both cannabis and tobacco and lived in one of the U.S. states with recreational cannabis legalized by the time of interview in 2019. They completed hypothetical purchase tasks to indicate the quantity desired of cannabis joints and cigarette packs 1) when only one substance was available with escalating prices and 2) when both substances were concurrently available with escalating prices of cannabis joints and a fixed price of cigarette packs. We estimated 1) the own-price elasticity of demand for each substance using nonlinear exponential demand model, and 2) the cross-price elasticity of demand at aggregate level using nonlinear exponential demand model and at individual level using log-linear demand model.

RESULTS

The estimates for the rate of change of own-price elasticity (α) were 0.0011 (SE = 0.000039, p < 0.001) for cannabis joints and 0.00095 (SE = 0.000037, p < 0.001) for cigarette packs. The aggregate-level estimates of cross-price elasticity (I = 13.032, SE = 0.34, p < 0.001; β = 0.0029, SE = 0.0021, p > 0.05) suggest an independent relationship between the two substances. At individual level, 78.70% of the participants treated the two substances as independent, 17.46% as complements, and 3.85% as substitutes.

CONCLUSIONS

For most adults who used both cannabis and tobacco in the U.S., cannabis joints and cigarettes had an independent relationship. Policies regulating the price of cannabis may not have large unintended consequences on cigarette use.

The clouded debate: A systematic review of comparative longitudinal studies examining the impact of recreational cannabis legalization on key public health outcomes

Background

Ineffective cannabis regulatory frameworks such as prohibition have sparked interest in alternative solutions to reduce individual and societal harms. While it has been suggested that the recreational legalization process has yielded early successes, the relatively recent implementation of the novel policies has provided a modest time frame for a truly thorough establishment and assessment of key population-level indicators. The following systematic review focuses on identifying the downstream public health sequelae of cannabis legalization policies, including parameters such as cannabis consumption rates, hospitalization rates, vehicular accidents and fatalities, criminal activity, and suicidal behaviors, as well as other substance use trends.

Methods

An exhaustive search of the MEDLINE and Google Scholar databases were performed to identify high-quality (1) longitudinal studies, which (2) compared key public health outcomes between regions which had and had not implemented recreational cannabis legalization (RML) policies, (3) using distinct databases and/or time frames. Thirty-two original research articles were retained for review.

Results

Adult past-month cannabis consumption (26+ years) seems to have significantly increased following RML, whereas young adult (18-26 years) and adolescent (12-17 years) populations do not show a significant rise in past-month cannabis use. RML shows preliminary trends in increasing service use (such as hospitalizations, emergency department visits, or poisonings) or vehicular traffic fatalities. Preliminary evidence suggests that RML is related to potential increases in serious/violent crimes, and heterogeneous effects on suicidal behaviors. While the research does not illustrate that RML is linked to changing consumptions patterns of cigarette, stimulant, or opioid use, alcohol use may be on the rise, and opioid prescribing patterns are shown to be significantly correlated with RML.

Conclusion

The current data supports the notion that RML is correlated with altered cannabis consumption in adults, potentially increased criminal activity, and a decline in opioid quantities and prescriptions provided to patients. Future work should address additional knowledge gaps for vulnerable populations, such as individuals with mental health problems or persons consuming cannabis frequently/at higher THC doses. The effects of varying legalization models should also be evaluated for their potentially differing impacts on population-level outcomes.

Comparing Substance Use and School-Based Stressors Among Black and Latinx Transgender Youth and Peers With Shared Minoritized Identities

PURPOSE

The aim of this study is to compare substance use and school-based stressors among Black and Latinx transgender youth (trans BLY), White transgender youth (trans WY), and Black and Latinx cisgender youth (cis BLY) and identify associations between substance use and stressors among trans BLY.

METHODS

We analyzed 2015-2017 Biennial California Healthy Kids Survey data with a weighted sample of the state's secondary school population. The analytic sample included 9th and 11th grade trans BLY, trans WY, and cis BLY. Past 30-day and lifetime substance use (cigarettes, e-cigarettes/vaping, marijuana, and alcohol) and school-based stressors (victimization, race-, gender-, and sexuality-based harassment) were compared between cohorts via logistic regression. For trans BLY, associations between substance use and stressors were assessed via logistic regression.

RESULTS

The analytic sample (n = 19,780) included 252 trans BLY, 104 trans WY, and 19,424 cis BLY. Among trans BLY, estimated prevalence of 30-day (and lifetime) use of cigarettes, e-cigarette/vaping, marijuana, and alcohol were 13% (23%), 19% (39%), 27% (42%), and 29% (48%), respectively. Trans BLY had similar odds of 30-day and lifetime use of all substances compared to trans WY but higher odds of use compared to cis BLY. For trans BLY, race- and gender-based harassment and higher victimization levels were associated with higher odds of 30-day and lifetime use of all substances. Sexuality-based harassment was associated with higher odds of 30-day and lifetime marijuana and alcohol use.

DISCUSSION

Trans BLY have high prevalence of substance use, comparable with trans WY but higher than cis BLY. Substance use among trans BLY is associated with school-based stressors.

Effects of cannabis regulation in Switzerland: Study protocol of a randomized controlled trial

Background

Cannabis is the most widely used illicit substance. Various countries have legalized cannabis for recreational use. Evidence on the health effects of cannabis regulation remains unclear and is mainly based on observational studies. To date, there is no randomized controlled study evaluating the impact of cannabis regulation for recreational use compared to the illicit market on relevant health indicators. The present study ("Weed Care") is the first to evaluate the impact of regulated cannabis access in pharmacies versus a waiting list control group representing the illicit market on problematic cannabis use as well as on mental and physical health.

Methods

The study is divided into two parts-a randomized controlled study of 6 months followed by an observational study of 2 years. Participants (N = 374) are randomly assigned to either the experimental group with access to legal cannabis in pharmacies or to the waiting list control group representing the current legal framework in Switzerland, namely the illicit market. After 6 months, all participants will have access to legal cannabis for the following 2 years (observational study). The primary outcome is problematic cannabis use as measured with the Cannabis Use Disorders Identification Test-Revised (CUDIT-R). Secondary outcomes are cannabis use patterns, mental disorders (e.g., depression, anxiety, and psychosis) and physical health (e.g., respiratory symptoms). Primary and secondary outcomes will be assessed online every 6 months. The study is approved by the responsible ethics committee as well as by the Swiss Federal Office of Public Health.

Discussion

Findings from this study may provide a scientific basis for future discussions about addiction medicine and cannabis policy in Switzerland.

Clinical Trial Registration

ClinicalTrials.gov (NCT05522205). https://clinicaltrials.gov/ct2/show/NCT05522205.

Short-Term Effects of Recreational Cannabis Legalization on Youth Cannabis Initiation

PURPOSE

As recreational cannabis is legalized, it is critical to know the impacts of legalization on youth cannabis use. Existing research generates conflicting results and does not shed light on channels of effects. This study investigates the impacts of legalization on youth cannabis initiation and overall cannabis use prevalence.

METHODS

We used Interrupted Time Series design and data from nationally-representative repeated cross-sectional Canadian surveys spanning 16 years. The primary outcomes were cannabis initiation rates and cannabis use prevalence among youths. The secondary outcomes were self-reported age of first cannabis use, ease of cannabis access, and perception of cannabis harm among youths.

RESULTS

After legalization, cannabis initiation rate among youths was 2.7 percentage points (95% confidence interval: 1.7-3.7; p < .01) or 69% higher, although there was no significant increase in the overall prevalence of cannabis use. Furthermore, there was a 4-month delay in the average age of first cannabis use among youths aged 17-18 years (95% confidence interval: 2.6-5.5 months; p < .01). The legalization was associated with greater perception of cannabis harm but also easier access to cannabis.

DISCUSSION

The impacts of legalization on youth cannabis use after 1 year are mixed. Although we observed an increase in cannabis initiation among youths who had never used cannabis, there was no change in the overall prevalence of cannabis use, implying a possible offsetting increase in cannabis cessation among existing users. To achieve legalization's goal of reducing youth cannabis use, policy measures are needed to curb youth cannabis access and initiation.

Does recreational cannabis legalization change cannabis use patterns? Evidence from secondary school students in Uruguay

BACKGROUND AND AIMS

In 2013, Uruguay became the first country to legalize and regulate the production and distribution of cannabis for recreational use. We measured whether Uruguay's non-commercial model of recreational cannabis legalization was associated with changes in the prevalence of risky and frequent cannabis use among secondary school students.

DESIGN

We used data from repeated cross-sectional surveys of secondary students in Uruguay and Chile (2007-2018). Using a difference-in-difference approach, we evaluated changes in the prevalence of past-year, past-month, any risky and frequent cannabis use following enactment (2014) and implementation (2016) of cannabis legalization among the full sample of secondary students and among students who reported past-year/month use. We examined changes separately for students ages 12 to 17, and students for whom cannabis became legally accessible, ages 18 to 21.

SETTING

Uruguay and Chile (2007-2018).

PARTICIPANTS

Secondary school students in 8th, 10th and 12th grade (n = 204 730).

MEASUREMENTS

Past-year and past-month cannabis use; any risky cannabis use measured with the Cannabis Abuse Screening Test (CAST); and frequent cannabis use (10+ days in the past-month).

FINDINGS

We found a decrease in past-year and past-month use following enactment or implementation. Among students ages 18 to 21, post-enactment, we observed a transitory increase in 2014 that decreased thereafter for: any risky use among those who reported past-year use (prevalence difference [PD] = 13.5%; 95% CI: 2.0, 24.9), frequent use in the full sample (PD = 4.5%; 95% CI: 1.0, 8.1), and frequent use among those who reported past-month use (PD = 16.8%; 95% CI: 1.9, 31.8).

CONCLUSION

The legalization of recreational cannabis in Uruguay was not associated with overall increases in either past-year/past-month cannabis use or with multi-year changes in any risky and frequent cannabis use among young people.

Temporal trends in alcohol, cannabis, and simultaneous use among 12th-grade U.S. adolescents from 2000 to 2020: Differences by sex, parental education, and race and ethnicity

BACKGROUND

Simultaneous use of alcohol and cannabis to enhance each other's effect can cause potential harm. Time trends are diverging in adolescent use of alcohol, which is declining, and cannabis, which is increasing among certain subgroups. However, little is known about trends in their simultaneous and non-simultaneous use. Racial and socioeconomic disparities are emerging in cannabis use, which may portend consequences to public health.

METHODS

The 2000 to 2020 Monitoring the Future surveys included approximately 38,000 U.S. 12th-grade students with information on simultaneous use and pertinent demographic factors. A 5-level alcohol/cannabis measure included past-year simultaneous use (i.e., alcohol and cannabis use at the same time), non-simultaneous alcohol and cannabis use, alcohol-use-only, cannabis-use-only, and no use. Multinomial logistic regressions estimated associations (adjusted relative risk ratios; aRRR) with time period (2000 to 2004, 2005 to 2009, 2010 to 2014, 2015 to 2020). Models were adjusted and included interactions with sex, race/ethnicity, and parental education.

RESULTS

Between 2000 and 2020, simultaneous alcohol/cannabis use among 12th graders decreased from 24.4% to 18.7%. From 2015 to 2020 compared to 2000 to 2004, the odds of simultaneous use (adjusted relative risk ratio (aRRR) vs. no use = 0.57, 95% CI [0.50, 0.66]) and alcohol-use-only (aRRR = 0.55, 95% CI [0.49, 0.61]) decreased, while cannabis-use-only odds increased (aRRR = 2.59, 95% CI [1.87, 3.59]). Notably, the prevalence of cannabis-use-only more than doubled from 2011 to 2019. The odds of simultaneous use, alcohol-use-only, and non-simultaneous use of alcohol and cannabis declined more rapidly among males than females, whereas the odds for cannabis-use-only increased faster for females than males. Increases in cannabis-use-only were faster for non-white adolescents.

CONCLUSION

Simultaneous use of alcohol and cannabis is declining among U.S. adolescents, but the decline is slower among females than males. Declines in simultaneous use are largely concomitant with historical declines in alcohol use, indicating that a continued focus on reducing alcohol use among adolescents and young adults has extended benefits to other adolescent substance use. However, cannabis use without any reported past-year alcohol use more than doubled in the last decade, a concerning trend.

Frequency of adolescent cannabis smoking and vaping in the United States: Trends, disparities and concurrent substance use, 2017-19

AIM

To quantify the trends in frequent and occasional cannabis vaping, demographic differences and concurrent nicotine and alcohol use.

DESIGN

Observational study. Survey-weighted multinomial logistic regression models assessed trends and disparities in past 30-day cannabis use. Trends were assessed overall and by sex, race/ethnicity, parental education and urbanicity. Multinomial logistic regression models also estimated associations of cannabis use (none, use without vaping, use with vaping) with past 2-week binge drinking and past 30-day nicotine/tobacco use.

SETTING

United States, 2017-19.

PARTICIPANTS

Participants in the national Monitoring the Future (n = 51 052) survey.

MEASUREMENTS

Past 30-day frequent cannabis use (six or more times/30 days) and past 30-day occasional use (one to five times/30 days), with and without vaping.

FINDINGS

Past 30-day frequent cannabis use with vaping and occasional use with vaping rose from 2017 to 2019. Past 30-day frequent and occasional cannabis use without vaping declined. Certain groups, such as Hispanic/Latino or lower socio-economic status adolescents, experienced particularly notable increases in frequent cannabis use with vaping (e.g. prevalence among Hispanic/Latino adolescents). Adolescents who reported smoking and vaping nicotine, and 10+ occasions of binge drinking, were 42.28 [95% confidence interval (CI) = 33.14-53.93] and 10.09 (95% CI = 4.51-22.53) times more likely to report past 30-day cannabis use with vaping, respectively, compared with no use.

DISCUSSION

Cannabis use without vaping appears to be declining among adolescents in the United States, while cannabis use with vaping is accelerating; frequent cannabis vaping is especially increasing, with consistent increases across almost all adolescent demographic groups. Cannabis use among US adolescents remains highly associated with other substance use.

Estimating the effects of legalizing recreational cannabis on newly incident cannabis use

Liberalized state-level recreational cannabis policies in the United States (US) fostered important policy evaluations with a focus on epidemiological parameters such as proportions [e.g., active cannabis use prevalence; cannabis use disorder (CUD) prevalence]. This cannabis policy evaluation project adds novel evidence on a neglected parameter–namely, estimated occurrence of newly incident cannabis use for underage (<21 years) versus older adults. The project’s study populations were specified to yield nationally representative estimates for all 51 major US jurisdictions, with probability sample totals of 819,543 non-institutionalized US civilian residents between 2008 and 2019. Standardized items to measure cannabis onsets are from audio computer-assisted self-interviews. Policy effect estimates are from event study difference-in-difference (DiD) models that allow for causal inference when policy implementation is staggered. The evidence indicates no policy-associated changes in the occurrence of newly incident cannabis onsets for underage persons, but an increased occurrence of newly onset cannabis use among older adults (i.e., >21 years). We offer a tentative conclusion of public health importance: Legalized cannabis retail sales might be followed by the increased occurrence of cannabis onsets for older adults, but not for underage persons who cannot buy cannabis products in a retail outlet. Cannabis policy research does not yet qualify as a mature science. We argue that modeling newly incident cannabis use might be more informative than the modeling of prevalences when evaluating policy effects and provide evidence of the advantages of the event study model over regression methods that seek to adjust for confounding factors.

A difference-in-difference approach to examining the impact of cannabis legalization on disparities in the use of cigarettes and cannabis in the United States, 2004-17

AIMS

To estimate the impact of recreational and medical cannabis laws (RCL, MCL) on the use of cannabis and cigarettes in the United States.

DESIGN

A difference-in-difference approach was applied to data from the 2004-17 National Survey on Drug Use and Health (NSDUH).

SETTING

United States.

PARTICIPANTS

Nationally representative cross-sectional survey of Americans aged 12 years and older (combined analytical sample for 2004-17, n = 783 663).

MEASUREMENTS

Data on past-month use of (1) cigarettes and (2) cannabis were used to classify respondents into four groups: cigarette and cannabis co-use, cigarette-only use, cannabis-only use or no cigarette or cannabis use. State of residence was measured by self-report. MCL/RCL status came from state government websites.

FINDINGS

Difference-in-difference analyses suggest that MCL was associated with an increase in cigarette-cannabis co-use overall [adjusted odds ratio (aOR) = 1.09; 95% confidence interval (CI) = 1.02-1.16], with the greatest increases among those aged 50 years and above (aOR = 1.60; CI = 1.39-1.84), married (aOR = 1.19; CI = 1.07-1.31), non-Hispanic (NH) black (aOR = 1.14; CI = 1.02-1.07) and with a college degree or above (aOR = 1.15; CI = 1.06-1.24). MCL was associated with increases in cigarette-only use among those aged 50 years and above (aOR = 1.07; CI = 1.01-1.14) and NH black (aOR = 1.16; CI = 1.06-1.27) and increases in cannabis-only use among those aged 50 years and above (aOR = 1.24; CI = 1.07-1.44) and widowed/divorced/separated (aOR = 1.18; CI = 1.01-1.37). RCL was associated with an increase in cannabis-only use overall (aOR = 1.21; 95% CI = 1.09-1.34), a decline in cigarette-only use overall (aOR = 0.89; 95% CI = 0.81-0.97) and increases in co-use among those who were married (aOR = 1.24; CI = 1.02-1.50) and aged 50 years and above (aOR = 1.37; CI = 1.03-1.84).

CONCLUSIONS

Recreational and medical cannabis legalization have had a varying impact on the use, and co-use, of cannabis and cigarettes in the United States.

Edible marijuana products and potential risks for pediatric populations

PURPOSE OF REVIEW

In recent years, an increasing number of states have legalized marijuana, also known as cannabis, for recreational use. As marijuana becomes more accessible, adolescent use and accidental pediatric exposures are likely to become broad public health concerns. Edible marijuana products, which are consumable foods or beverages that contain cannabis extract, are particularly enticing to youth, as they come in appealing forms such as candies, cookies, and drinks. The purpose of this review is to provide pediatricians with an overview of the different types and potential dangers associated with edible marijuana products.

RECENT FINDINGS

Edible marijuana products are often indistinguishable in appearance from normal food items and lack the smell and visible smoke associated with inhaled marijuana. Because they are inconspicuous, palatable, and easily accessible, they are increasingly popular among adolescents. Additionally, the packaging of edible baked goods, candies, and drinks is often purposefully very similar to that of mainstream foods, increasing the risk of accidental ingestion by children. An edible marijuana product must be digested before Δ9-tetrahydrocannabinol can enter the bloodstream, so there is a delayed onset of effects when consuming edibles compared with inhaling marijuana. This also predisposes users to accidental overconsumption.

SUMMARY

Greater knowledge of edible marijuana product consumption by pediatric populations will allow pediatricians to more effectively help patients and advise caregivers in cases of overconsumption, dependence, or accidental ingestion. It is important for parents, guardians, and educators to be able to successfully identify edible marijuana products and recognize signs of cannabis use.

A Systematic Review and Narrative Synthesis of the Evolution of Adolescent and Young Adult Cannabis Consumption Before and After Legalization

PURPOSE

To systematically review evidence assessing the evolution of cannabis consumption before and after the implementation of non-medical cannabis legislation.

METHODS

MEDLINE, PubMED, PsycINFO, Scopus, and Web of Science were systematically searched for studies that examined change in cannabis consumption before and after nonmedical cannabis legislation. Data were tabulated by study design, levels of consumption, and individual subgroups. Data were analyzed using a narrative synthesis approach, considering study quality.

RESULTS

32 studies were included (11 higher quality and 21 lower quality). 40% of higher quality evidence supported an increase in postlegalization consumption (55% did not report a change and 5% reported a decrease). The increase was most evident for young adults (42% of higher quality evidence) and in the consumption in the past month (37% of higher quality evidence). There was limited supporting evidence for new users having grown in response to legalization. Based on subgroup analysis, the increase in postlegalization consumption was higher among women and those who engage in binge-drinking.

CONCLUSIONS

Higher quality evidence suggests an increase in adolescent past-month consumption of cannabis following legalization in several geographical jurisdictions. Consumption evolution prelegalization and postlegalization differed by age group and for young women and for binge drinkers. Consumption evolution differences suggest a variety of strategies might be required in efforts to lower public health impacts of cannabis consumption following legalization.

Relationships of Cannabis Policy Liberalization With Alcohol Use and Co-Use With Cannabis: A Narrative Review

PURPOSE

The liberalization of cannabis policies has the potential to affect the use of other substances and the harms from using them, particularly alcohol. Although a previous review of this literature found conflicting results regarding the relationship between cannabis policy and alcohol-related outcomes, cannabis policies have continued to evolve rapidly in the years since that review.

SEARCH METHODS

The authors conducted a narrative review of studies published between January 1, 2015, and December 31, 2020, that assessed the effects of cannabis policies on the use of alcohol in the United States or Canada.

SEARCH RESULTS

The initial search identified 3,446 unique monographs. Of these, 23 met all inclusion criteria and were included in the review, and five captured simultaneous or concurrent use of alcohol and cannabis.

DISCUSSION AND CONCLUSIONS

Associations between cannabis policy liberalization and alcohol use, alcohol-related outcomes, and the co-use of alcohol and cannabis were inconclusive, with studies finding positive associations, no associations, and negative associations. Although several studies found that cannabis policy liberalization was associated with decreases in alcohol use measures, these same studies showed no impact of the cannabis policy on cannabis use itself. The lack of a consistent association was robust to subject age, outcome measure (e.g., use, medical utilization, driving), and type of cannabis policy; however, this may be due to the small number of studies for each type of outcome. This paper discusses several notable limitations of the evidence base and offers suggestions for improving consistency and comparability of research going forward, including a stronger classification of cannabis policy, inclusion of measures of the alcohol policy environment, verification of the impact of cannabis policy on cannabis use, and consideration of mediation effects.

Public Health Implications of Cannabis Legalization: An Exploration of Adolescent Use and Evidence-Based Interventions

This article examines the relaxation of state marijuana laws, changes in adolescent use of marijuana, and implications for drug education. Under federal law, use of marijuana remains illegal. In spite of this federal legislation, as of 1 June 2021, 36 states, four territories and the District of Columbia have enacted medical marijuana laws. There are 17 states, two territories and the District of Columbia that have also passed recreational marijuana laws. One of the concerns regarding the enactment of legislation that has increased access to marijuana is the possibility of increased adolescent use of marijuana. While there are documented benefits of marijuana use for certain medical conditions, we know that marijuana use by young people can interfere with brain development, so increased marijuana use by adolescents raises legitimate health concerns. A review of results from national survey data, including CDC’s YRBS, Monitoring the Future, and the National Household Survey on Drug Use, allows us to document changes in marijuana use over time. Increased legal access to marijuana also has implications for educational programming. A “Reefer Madness” type educational approach no longer works (if it ever did). We explore various strategies, including prevention programs for education about marijuana, and make recommendations for health educators.

Impact of recreational cannabis legalization on cannabis use, other substance use, and drug-related offending among justice-system-involved youth

The present study assessed whether cannabis use, other types of substance use, and drug-related offending changed among 1216 justice-system-involved youth after recreational cannabis legalization. Using generalized estimating equation population-averaged models, we compared youth in California, where recreational cannabis is legalized, and Pennsylvania, where recreational use is still prohibited. Results indicated that cannabis use, cannabis selling, and driving under the influences (DUIs) increased more among Pennsylvanian than Californian youth. We found no changes in alcohol or noncannabis drug use after legalization. Cigarette use did not change significantly among Pennsylvanian youth, but Californian youth exhibited decreased cigarette use after legalization. Although not directly tested in the present analysis, it is possible that changes in state-level recreational cannabis policies throughout the U.S. may contribute to more permissive attitudes toward cannabis, which leads to higher use and use-related outcomes. Future research should continue to consider the potential impacts of legalization on other types of risky and illegal behavior.

Association of Marijuana Legalization With Marijuana Use Among US High School Students, 1993-2019

This cross-sectional study assesses the association between US state legalization of medical and recreational marijuana use and use of marijuana by adolescents.

Relationships between age at first substance use and persistence of cannabis use and cannabis use disorder

Background

From a secondary prevention perspective, it is useful to know who is at greatest risk of progressing from substance initiation to riskier patterns of future use. Therefore, the aim of this study was to determine relationships between age at first use of alcohol, tobacco and cannabis and patterns of cannabis use, frequency of use and whether age of substance use onset is related to having a cannabis use disorder (CUD).

Methods

We analysed data from Ireland’s 2010/11 and 2014/15 National Drug Prevalence Surveys, which recruited 5134 and 7005 individuals respectively, aged 15 years and over, living in private households. We included only those people who reported lifetime cannabis use. Multinomial, linear and binary logistic regression analyses were used to determine relationships between age of substance use onset and patterns of cannabis use, frequency of use and having a CUD.

Results

When compared to former users, the odds of being a current cannabis user were found to be reduced by 11% (OR = 0.89; 95% CI: 0.83, 0.95) and 4% (OR = 0.96; 95% CI: 0.92, 1.00) for each year of delayed alcohol and cannabis use onset, respectively. Among current users, significant inverse linear relationships were noted, with increasing age of first use of tobacco (β = − 0.547; P < .001) and cannabis (β = − 0.634; P < .001) being associated with a decreased frequency of cannabis use within the last 30 days. The odds of having a CUD were found to be reduced by 14% (OR = 0.86; 95% CI: 0.78, 0.94) and 11% (OR = 0.89; 95% CI: 0.82, 0.98) for each year of delayed tobacco and cannabis use onset respectively in analyses which examined survey participants aged 15–34 years.

Conclusions

Among people who report past cannabis use, it is those with a more precocious pattern of early use of substances, including alcohol, and especially tobacco and cannabis, who are more likely to report ongoing, heavy and problematic cannabis use. Secondary prevention initiatives should prioritise people with a pattern of very early onset substance use.