Recreational marijuana legalization and college student use: Early evidence

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Cannabis Dependence is Associated with Reduced Hippocampal Subregion Volumes Independently of Sex: Findings from an ENIGMA Addiction Working Group Multi-Country Study

Background: Males and females who consume cannabis can experience different mental health and cognitive problems. Neuroscientific theories of addiction postulate that dependence is underscored by neuroadaptations, but do not account for the contribution of distinct sexes. Further, there is little evidence for sex differences in the neurobiology of cannabis dependence as most neuroimaging studies have been conducted in largely male samples in which cannabis dependence, as opposed to use, is often not ascertained. Methods: We examined subregional hippocampus and amygdala volumetry in a sample of 206 people recruited from the ENIGMA Addiction Working Group. They included 59 people with cannabis dependence (17 females), 49 cannabis users without cannabis dependence (20 females), and 98 controls (33 females). Results: We found no group-by-sex effect on subregional volumetry. The left hippocampal cornu ammonis subfield 1 (CA1) volumes were lower in dependent cannabis users compared with non-dependent cannabis users (p<0.001, d=0.32) and with controls (p=0.022, d=0.18). Further, the left cornu ammonis subfield 3 (CA3) and left dentate gyrus volumes were lower in dependent versus non-dependent cannabis users but not versus controls (p=0.002, d=0.37, and p=0.002, d=0.31, respectively). All models controlled for age, intelligence quotient (IQ), alcohol and tobacco use, and intracranial volume. Amygdala volumetry was not affected by group or group-by-sex, but was smaller in females than males. Conclusions: Our findings suggest that the relationship between cannabis dependence and subregional volumetry was not moderated by sex. Specifically, dependent (rather than non-dependent) cannabis use may be associated with alterations in selected hippocampus subfields high in cannabinoid type 1 (CB1) receptors and implicated in addictive behavior. As these data are cross-sectional, it is plausible that differences predate cannabis dependence onset and contribute to the initiation of cannabis dependence. Longitudinal neuroimaging work is required to examine the time-course of the onset of subregional hippocampal alterations in cannabis dependence, and their progression as cannabis dependence exacerbates or recovers over time.

Marijuana Message Channels, Health Knowledge, Law Knowledge, and Confidence in Knowledge as Risk and Protective Factors of Marijuana Use among College Students

Marijuana use among U.S. college students is the highest since the mid-1980s. Because knowledge about marijuana and confidence in the knowledge are related to changing marijuana laws and marijuana-related messages ubiquitous in college students' information environment, we examined their relationships with use. The Structural Equation Modeling method was used to analyze the relationships using survey responses from 249 college students in an adult-use marijuana legal state. Marijuana health knowledge was related to less use, and law knowledge was related to more use. Both relationships were mediated by perceived risk. Confidence in knowledge was related to more use directly as well as indirectly via lower peer disapproval and lower perceived risk. Among various marijuana message channels, peers were the most influential, contributing to lower health knowledge and higher confidence in knowledge.

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.

Health, safety, and socioeconomic impacts of cannabis liberalization laws: An evidence and gap map

Background

Globally, cannabis laws and regulations are rapidly changing. Countries are increasingly permitting access to cannabis under various decriminalization, medicalization, and legalization laws. With strong economic, public health, and social justice incentives driving these domestic cannabis policy reforms, liberalization trends are bound to continue. However, despite a large and growing body of interdisciplinary research addressing the policy-relevant health, safety, and socioeconomic consequences of cannabis liberalization, there is a lack of robust primary and systematic research that comprehensively investigates the consequences of these reforms.

Objectives

This evidence and gap map (EGM) summarizes the empirical evidence on cannabis liberalization policies. Primary objectives were to develop a conceptual framework linking cannabis liberalization policies to relevant outcomes, descriptively summarize the empirical evidence, and identify areas of evidence concentration and gaps.

Search Methods

We comprehensively searched for eligible English-language empirical studies published across 23 academic databases and 11 gray literature sources through August 2020. Additions to the pool of potentially eligible studies from supplemental sources were made through November 2020.

Selection Criteria

The conceptual framework for this EGM draws upon a legal epidemiological perspective highlighting the causal effects of law and policy on population-level outcomes. Eligible interventions include policies that create or expand access to a legal or decriminalized supply of cannabis: comprehensive medical cannabis laws (MCLs), limited medical cannabidiol laws (CBDLs), recreational cannabis laws (RCLs), industrial hemp laws (IHLs), and decriminalization of cultivations laws (DCLs). Eligible outcomes include intermediate responses (i.e., attitudes/behaviors and markets/environments) and longer-term consequences (health, safety, and socioeconomic outcomes) of these laws.

Data Collection and Analysis

Both dual screening and dual data extraction were performed with third person deconfliction. Primary studies were appraised using the Maryland Scientific Methods Scale and systematic reviews were assessed using AMSTAR 2.

Main Results

The EGM includes 447 studies, comprising 438 primary studies and nine systematic reviews. Most research derives from the United States, with little research from other countries. By far, most cannabis liberalization research focuses on the effects of MCLs and RCLs. Studies targeting other laws-including CBDLs, IHLs, and DCLs-are relatively rare. Of the 113 distinct outcomes we documented, cannabis use was the single most frequently investigated. More than half these outcomes were addressed by three or fewer studies, highlighting substantial evidence gaps in the literature. The systematic evidence base is relatively small, comprising just seven completed reviews on cannabis use (3), opioid-related harms (3), and alcohol-related outcomes (1). Moreover, we have limited confidence in the reviews, as five were appraised as minimal quality and two as low quality.

Authors’ Conclusions

More primary and systematic research is needed to better understand the effects of cannabis liberalization laws on longer-term-and arguably more salient-health, safety, and socioeconomic outcomes. Since most research concerns MCLs and RCLs, there is a critical need for research on the societal impacts of industrial hemp production, medical CBD products, and decriminalized cannabis cultivation. Future research should also prioritize understanding the heterogeneous effects of these laws given differences in specific provisions and implementation across jurisdictions.

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.

Disparities in cannabis use and documentation in electronic health records among children and young adults

The legalizations of medical and recreational cannabis have generated a great deal of interest in studying the health impacts of cannabis products. Despite increases in cannabis use, its documentation during clinical visits is not yet mainstream. This lack of information hampers efforts to study cannabis's effects on health outcomes. A clear and in-depth understanding of current trends in cannabis use documentation is necessary to develop proper guidelines to screen and document cannabis use. Here we have developed and used a natural language processing pipeline to evaluate the trends and disparities in cannabis documentation. The pipeline includes a screening step to identify clinical notes with cannabis use documentation which is then fed into a BERT-based classifier to confirm positive use. This pipeline is applied to more than 23 million notes from a large cohort of 370,087 patients seen in a high-volume multi-site pediatric and young adult clinic over a period of 21 years. Our findings show a very low but growing rate of cannabis use documentation (<2%) in electronic health records with significant demographic and socioeconomic disparities in both documentation and positive use, which requires further attention.

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.

Comparing National College Health Assessment with other surveys of cannabis use and binge drinking among young adult college students 2008-2018

Objective: We considered the utility of National College Health Assessment (NCHA) data relative to other national data for studying college students' cannabis use and binge drinking, and drug policy effects. Participants: Survey data on 18-22-year old college students were drawn from the 2008-2018 NCHA, National Survey on Drug Use and Health (NSDUH), Monitoring the Future (MTF), and Healthy Minds Study (HMS). Methods: Prevalence estimates were compared across data sources in terms of level and change from 2008-2018 using linear regressions, separately for men and women. Results: Mean prevalence estimates for 30-day cannabis use and 2-week binge drinking, and linear time trends did not differ significantly among NCHA, NSDUH, and MTF. Conclusions: NCHA prevalence estimates are similar to those from NSDUH and MTF, NCHA has unique strengths, and some weaknesses can be offset. Findings support the value of NCHA for studying college students' substance use and effects of drug policy.

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.

Perceptions and Practices of Cannabis Use Among Emergency Department Patients

BACKGROUND

Nationally, in states where cannabis has been legalized, increases in cannabis-related hospitalizations and emergency department (ED) visits have also been observed.

OBJECTIVES

This study aims to: 1) Describe the sociodemographic characteristics of cannabis users presenting to two academic EDs in California; 2) Assess cannabis-related behaviors; 3) Assess perceptions of cannabis; 4) Identify and describe reasons for cannabis-related ED utilization.

METHODS

This is a cross-sectional study of patients visiting one of two academic EDs between February 16, 2018 and November 21, 2020. Eligible participants completed a novel questionnaire developed by the authors. Basic descriptive statistics, Pearson correlation coefficients, and logistic regression were used for statistical analysis of responses.

RESULTS

The questionnaire was completed by 2577 patients. A quarter were categorized as Current Users (n = 628, 24.4%). Current, Regular Users were evenly divided across gender, were relatively younger (18-34 years, 48.1%), and were largely non-Hispanic Caucasian. Over half of all respondents believed that the use of cannabis was less harmful than tobacco or alcohol use (n = 1537, 59.6%). One in five Current Users (n = 123, 19.8%) reported driving while using cannabis in the past month. A small proportion (n = 24, 3.9%) of Current Users reported ever visiting the ED for a cannabis-related chief complaint.

CONCLUSIONS

Overall, many ED patients are currently using cannabis; few report utilizing the ED due to cannabis-related problems. Current, Irregular Users may represent the ideal target group for ED-based educational efforts aimed at improving knowledge of safe cannabis use.

Recreational Cannabis Legislation: substance use and impaired driving among Canadian rural and urban postsecondary students

BACKGROUND

Investigation of cannabis use trends among emerging adults (EA, aged between 18 and 24 years) following 2018 Canadian Recreational Cannabis Legislation (RCL) is critical. EAs report the heaviest cannabis use in Canada and are particularly vulnerable to the onset of problematic substance use.

OBJECTIVES

To describe and compare post-RCL use of cannabis and other state-altering substances, as well as the prevalence of impaired driving, among EA postsecondary students in both rural and urban settings, studying on one of five campuses in either Manitoba, Ontario, or Quebec.

METHODS

For this quantitative cross-sectional study, a self-report survey was administered to 1496 EA postsecondary students in the months following RCL (2018-2019). Multiple logistic regression analyses were conducted to explore the influence of provincial and urban/rural living contexts on recreational cannabis use, other state-altering substance use and impaired driving behaviours, adjusting for sociodemographic variables.

RESULTS

Statistically significant differences were observed between cohorts in almost all measures. Quebec students were more likely to have consumed cannabis during their lifetime (AOR = 1.41, 95% CI [1.05, 1.90]) than all other cohorts. Rural cohorts all had greater odds of reporting consumption of cannabis during the previous year compared to urban cohorts (AOR = 1.32, 95% CI [1.04, 1.67]). However, the relation between cannabis use in the last month and operating a motor vehicle after using cannabis (lifetime and past month) and living context differed between subjects in Quebec and those in the two other provinces. Quebec's students having lived mostly in urban contexts had greater odds of using cannabis in the past month and operating a motor vehicle after using cannabis (lifetime and past month) than those in rural contexts; the opposite was observed in Manitoba and Ontario. Differing interprovincial prohibitive/permissive legislation and licit cannabis infrastructure appeared to have little impact on post-RCL substance use.

CONCLUSIONS

In Manitoba and in Ontario, rural/urban living context seems to better predict substance use and related road-safety practices, suggesting these trends supersede permissive/prohibitive provincial legislation and licit cannabis-related infrastructures. Further investigation into sociodemographic factors influencing state-altering substance use and impaired driving, and maintaining tailored cannabis misuse prevention campaigns, is warranted on Canadian campuses.

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.

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 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.

Assessing Increases in Cannabis-Related Diagnoses in US Hospitals by Regional Policy Status

Cannabis policy is rapidly changing and more individuals are using cannabis nationally. Despite increased use and known adverse outcomes to cannabis use, there is a lack of understanding of health care utilization for cannabis-related conditions. The objectives of this study were: (1) To understand the change in the incidence of cannabis-related diagnoses from 2012 to 2015 nationally and (2) to describe the relationship between regional cannabis policies and changes in the incidence of cannabis-related diagnoses from 2012 to 2015. National Inpatient Sample (NIS) data from the Healthcare Cost and Utilization Project for 2012 and 2015 were analyzed using SPSS software for incidence of cannabis diagnoses. Previously defined NIS regions were assigned a policy status related to medical and recreational cannabis laws. Comparisons were made at the national and regional levels to better understand change in incidence of diagnoses. From 2012 to 2015, there was a 26.7% increase in cannabis-related diagnoses in the inpatient setting nationally. All 9 regions showed increases in the incidence of cannabis-related diagnoses ranging from 15.5% to 41.9% regardless of cannabis policy. As cannabis policy increased legal access, cannabis-related diagnoses increased nationally and regionally across the United States from 2012 to 2015 regardless of cannabis policy. Continued tracking of cannabis-related diagnoses is needed to identify where interventions are necessary to reduce negative impacts of increased cannabis use.

Watching the grass grow: does recreational cannabis legalization affect retail and agricultural wages?

Background

Over the past several years, cannabis has become legal for recreational use in many US states and jurisdictions around the world. The opening of these markets has led to the establishment of hundreds of cannabis production and retail firms with accompanying demand for labor, leading to concerns about spillover effects on wages from incumbents.

Methods

We study the markets for agricultural and retail labor in Washington and Colorado from 2000 to 2019 using differences-in-differences with synthetic controls. We employ employment data from the Quarterly Census of Employment and Wages, state-level demographic data from the US Census Bureau, and agricultural data from the National Agricultural Statistics Service. We use the least absolute shrinkage and selection operator (LASSO) for variable selection and classification and regression trees (CART) for chained imputation of missing values.

Results

We find little-to-no evidence of a significant difference in weekly wages per worker generated by cannabis legalization: the log of the weekly wage per worker decreases by 0.013 in Washington’s agricultural sector (p value 0.091) and increases by 0.059 in Washington’s retail sector (p value 0.606). Results in Colorado are qualitatively similar. These results are limited in part by the short post-legalization period of the data.

Conclusions

Cannabis legalization is unlikely to negatively impact incumbent agriculture or retail firms through the labor market channel.

Sharing pro-marijuana messaging on social media: The moderating role of legislation

ObjectivesThis study investigates whether recreational marijuana legislation and perceived social norms (descriptive and injunctive) affect college students' propensity to share pro-marijuana messages. We examine which referent group (close friends, typical student, parents) most influence those norms. Participants: A sample of 343 college students participated in the study. Of these students, 214 were from Washington State, where recreational marijuana is legal, and 129 were from Wyoming, where recreational marijuana is illegal. Method: Data, from an online survey, were analyzed through PROCESS analyses. Results: College students in Washington State who believed a typical peer would want them to share pro-marijuana messaging were marginally more likely to share pro-marijuana messages than their counterparts in Wyoming. However, among students who thought a typical peer would not approve of them sharing pro-marijuana messaging, the opposite pattern emerged. Conclusion: Restrictive recreational marijuana legislation does not uniformly abate related message sharing on social media.

Does expanding access to cannabis affect traffic crashes? County-level evidence from recreational marijuana dispensary sales in Colorado

This article examines the effect of recreational cannabis dispensary sales on traffic crashes by employing difference-in-differences model that exploits the variation in the timing of recreational marijuana dispensary entry across counties within Colorado. Using marijuana-related hospital discharge as a measure of marijuana abuse/misuse, the results indicate a sizable rise in marijuana-related hospital discharges after the entry of retail cannabis stores. However, there is a lack of evidence that traffic crash incidents are affected by the entry. The preferred estimate suggests that, at 90% confidence level, a large increase in traffic crashes by more than 5% can be ruled out.

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.

Marijuana knowledge, confidence in knowledge, and information efficacy as the protective and risk factors of marijuana use among college students

Objective This study explored the relationships between marijuana knowledge, confidence in knowledge, and information efficacy and marijuana use. Furthermore, the effects of the knowledge-related variables were examined on intention to use, resistance efficacy, and intention to vote for legalization. Participants: Undergraduate students (N = 215) were surveyed in Fall 2018. Methods: Data were collected online and analyzed through a series of regression analyses. Results: Higher knowledge was related to less use via higher perceived risk whereas higher confidence in knowledge was related to more use. Marijuana use was related to higher future intention to use, lower resistance self-efficacy, and intention to vote for legalization. Information efficacy was related to intention to vote for legalization only. Conclusions: Students with more knowledge were less likely to use marijuana, whereas students who considered themselves well-informed were more likely to use it. Future intervention efforts will benefit from counteracting students' misplaced confidence in their knowledge.

A Scoping Review of Associations Between Cannabis Use and Anxiety in Adolescents and Young Adults

Cannabis and anxiety are both rising issues that impact young people. This review seeks to explore the association between anxiety and cannabis in adolescents and young adults (AYA). A database search was run retrospectively from July 2020 through calendar year 2013. Articles had to present outcomes examining cannabis use and symptoms of anxiety, be written in English, contain samples with ≥ 50% who are age 25 or younger, and be published in a peer-reviewed journal. Forty-seven studies were identified that examined the relationship between anxiety and cannabis use. Twenty-three studies found a positive association that greater anxiety among AYA was associated with greater cannabis use. In contrast, seven studies found a negative association that greater anxiety was related to less cannabis use. And finally, 17 studies found no clear association between anxiety and cannabis use. Further research is needed to better understand the relationship between anxiety and cannabis use.

GEOGRAPHICAL ACCESS TO RECREATIONAL MARIJUANA

We investigate whether adult marijuana use in Washington responds to increased local access as measured by drive time to the nearest legal marijuana retailer as well as measures of retail density. Using survey data from the Behavioral Risk Factor Surveillance System, we find that as retailers open closer to where they live, more individuals use marijuana and more frequently. These effects are concentrated among young adults (ages 18-26), women, and rural residents. Controlling for distance to the nearest retailer, we find that whether retail density affects marijuana use depends on how it is measured.

The Potential Impact of Legalization of Recreational Cannabis among Current Users: A Qualitative Inquiry

Given legislative initiatives in Rhode Island pertaining to consideration of cannabis legalization for recreational purpose, a qualitative inquiry was conducted regarding anticipated changes in use among recreational cannabis users in Rhode Island. Five focus groups were conducted with recreational cannabis users (N = 31; 6-7 per group). Participants were queried about anticipated impact of legalization on their use patterns. Themes were identified using applied thematic analysis. Participants discussed (1) a desire to maintain the status quo due to satisfaction with local cannabis regulations and their current use behaviors, (2) how and why cannabis use may change, including pros and cons of legalization, and (3) anticipated changes in purchasing behavior given display and legitimacy of legal dispensaries. While participants anticipate use levels and prevalence may remain relatively stable following legislation changes, findings suggest possible changes related to mode of administration and location of use. Public health concerns exist related to high-risk potencies and use of cannabis in edible form; therefore, trialing of new cannabis products has important clinical implications should legalization occur in Rhode Island.

Cannabis use and misuse in the year following recreational cannabis legalization in Canada: A longitudinal observational cohort study of community adults in Ontario

BACKGROUND

Canada legalized cannabis for non-medical purposes federally in October 2018. This study examined changes in cannabis use over the following year in a sample of general community adults. A secondary aim was to examine forecasted cannabis use following legalization in relation to actual post-legalization cannabis use.

METHODS

Participants were 1502 community adults (61 % female; age M = 34.60 ± 13.95), with approximately half reporting any cannabis use in the six months prior to legalization (Cannabis+ group [48 %]/Cannabis- group [52 %]). Self-report assessments were conducted in the month before cannabis legalization, 6-months post-legalization and 12-months post-legalization. Primary outcomes were frequency of cannabis use, grams of dried flower cannabis on days used, and level of misuse (Cannabis Use Disorder Identification Test - Revised). Secondary analyses examined pre-legalization personal forecasts in relation to post-legalization cannabis use.

RESULTS

Statistically significant main effects of time (ps<.001), cannabis use status (ps<.001), and time × cannabis use status interactions (ps<.001) were present for cannabis frequency, quantity, and level of misuse. In each case, the interactions reflected significant decreases in the Cannabis+ group, but significant increases in the Cannabis- group. Approximately 15 % of participants erroneously forecasted their personal post-legalization cannabis use, with discrepancies most commonly being individuals who were not using prior to legalization subsequently using cannabis.

CONCLUSIONS

In this cohort of community adults, we observed significant changes over the first year following Canadian legalization, with divergent trajectories based on pre-legalization cannabis use. These findings suggest multifarious impacts of legalization in adults, with meaningfully different trajectories among subgroups.

Demographic and policy-based differences in behaviors and attitudes towards driving after marijuana use: an analysis of the 2013-2017 Traffic Safety Culture Index

OBJECTIVE

Marijuana policies in the United States have become more permissive, motivating research on demographic and policy-based differences in behaviors and attitudes towards driving after marijuana use. The Traffic Safety Culture Index is an annual survey with national scope and multiple measures relevant to driving after marijuana use. We tabulated responses to questions about driving after marijuana use from the Traffic Safety Culture Index based on demographic factors, recreational and medical marijuana policies, and per-se marijuana laws.

RESULTS

Male, younger, lower-income, and lower-education respondents self-reported driving after marijuana use more than their demographic counterparts, more often reported such behavior to be personally acceptable, and exhibited lower support per-se laws. Drivers in states that legalized medical marijuana self-reported driving after marijuana use slightly more than drivers in states where both medical and recreational were illegal. Support for per-se laws was higher among those in states that legalized recreational marijuana and in states with per-se laws. Demographic differences in our outcomes were consistent and cohesive. On the other hand, we found no predominant pattern suggesting that those in states with liberal marijuana policies were more tolerant of driving after marijuana use.

Changes in Medical Cannabis Patient Status before and after Cannabis Legalization in California: Associations with Cannabis and Other Drug Use

It is unknown how patterns of cannabis and other drug use changed among young adult cannabis users as they became, exited or stayed medical cannabis patients (MCPs) after California legalized cannabis for adult use in 2016. A cohort of 18-26 year-old cannabis users was recruited in Los Angeles in 2014-15 (64.8% male; 44.1% Hispanic/Latinx). Based on wave 1 (pre-legalization) and wave 4 (post-legalization) MCP status, four transition groups emerged: MCP, Into MCP, Out of MCP and NPU (non-patient user). Relationships between self-reported medical cannabis use, transition group membership, and cannabis/other drug use outcomes were examined. Changes in cannabis practices were consistent with changes in MCP status. Cannabis days, concentrate use, self-reported medical cannabis use and driving under influence of cannabis were highest among MCP, increased for Into MCP, and decreased for Out of MCP in wave 4. A majority of drug use outcomes decreased significantly by wave 4. Self-reported medical cannabis use was associated with more frequent cannabis use but less problematic cannabis and other drug use. Future studies should continue to monitor the impact of policies that legalize cannabis for medical or recreational use, and medical motivations for cannabis use on young adults' cannabis and other drug use.

Enhancing gender and ethnic representativeness of NCHA-II data with survey weights: The examples of substance use prevalence and state marijuana legalization

We evaluated how applying post-stratification sampling weights to National College Health Assessment II (NCHA-II) data affects estimates of substance use prevalence and tests of medical and recreational marijuana legalization (MML and RML) effects. Participants/Methods: We constructed weights for Fall 2015 and Spring 2016 surveys (n = 90,503) using population information on U.S. undergraduates' gender and race/ethnicity and three institutional characteristics (region, city population, public/private). We estimated substance use prevalence (e.g., e-cigarettes, prescription opioid misuse) and compared 30-day marijuana use rates in states with RML, MML, or neither policy. Results: When unweighted versus weighted data were used, prevalence estimates did not differ appreciably; conclusions from logistic regressions were similar (weighted 30-day marijuana use rates among undergraduates in RML, MML, and non-ML states were 30.0%, 20.3%, and 16.3%, respectively) but effect sizes differed. Conclusions: The value of using weighted NCHA-II data depends on the analysis and the precision required for the research questions.

Gender differences in the risk and protective factors of marijuana use among U.S. College students

Gender differences in the risk and protective factors of marijuana use among college students were explored by analyzing online survey responses from 464 undergraduates. Women perceived higher risk and used marijuana less than men, with no gender difference in peer disapproval. In addition, women had higher objective knowledge regarding the health effects of marijuana, although they exhibited lower confidence in their knowledge. In subsequent regression analyses, health knowledge, confidence in knowledge, perceived risk, and peer disapproval predicted women's marijuana use, whereas only confidence in knowledge and perceived risk predicted men's use. These findings can help devise effective intervention strategies.

Cannabis Legalization and College Mental Health

PURPOSE OF REVIEW

To assess how the changing landscape of marijuana use affects the developing brain and mental health of college students.

RECENT FINDINGS

Legalization of cannabis may facilitate use in the college population, with 38% of college students, whose brains are still maturing, regularly using marijuana products. Earlier and increased use, higher potency, pre-existing issues, and genetic predispositions increase negative outcomes by precipitating or worsening mental illness and ultimately impacting academic success. In the USA, the sharpest increase in cannabis users following legalization has been in the college age population (18-25 years of age). This population is especially vulnerable to the negative impacts and risks associated with cannabis use, including risk for the onset of major psychiatric illness. College mental health practitioners should remain informed about health effects of cannabis use, assess patient use on a regular basis, provide education and be familiar with interventions to reduce harm.

Cannabis use among Norwegian university students: Gender differences, legalization support and use intentions, risk perceptions, and use disorder

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Past year cannabis use was fairly common in a sample of Norwegian college students.

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About 6% of users possibly met criteria for use disorder, function of use frequency.

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Legalization attitudes and risk perceptions were associated with cannabis use risk.

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Intentions to use cannabis if legal were evident even among some current non-users.

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Many non-users expressed uncertainty in legalization attitudes and risk perceptions.

Aims

We explored past-year cannabis use and associated characteristics, focusing on legalization attitudes, use intentions, risk perceptions, and possible dependence among Norwegian university/college students.

Methods

We examined a nation-wide sample of Norwegian university/college students (N = 49,688; 67% female) who participated in the Students’ Health and Wellbeing Study (SHoT-study) in 2018. Participants reported past-year substance use, support for cannabis legalization, intent to use cannabis if legal, and perceived risks of weekly use. Past-year cannabis use (including use frequency) was examined in relation to these indicators. Legalization support, use intentions, and risk perceptions were examined in relation to use and gender. Potential cannabis use disorder was assessed with the Cannabis Abuse Screening Test (CAST) and examined in relation to use frequency and gender.

Findings

Past-year use was reported by 15.3% (11.8% women; 22.9% men). Majority of current users (roughly 90%) used no more than 50 times past year, and 6% (3.8% women; 8.5% men) met CAST use disorder criteria. Legalization support, use intentions, and no/low risk perceptions were significantly associated with greater odds of use, and greater use frequency among current users in both crude and adjusted models. Legalization support (23.0%), use intentions (14.0%), and perceptions of no/low risk (29.2%) were also relatively common even among current non-users, especially men. Male gender and more frequent use were associated with greater CAST scores and greater odds of use disorder.

Conclusions

Cannabis use was relatively common in this student sample. In addition to targeting frequent use, interventions may focus on cannabis-related attitudes and risk perceptions among uncertain/uninformed students.

Marijuana legalization and disability claiming

We study the effect of recent legalization of recreational marijuana use laws (RMLs) in the United States on new applications and allowances for Social Security Disability Insurance and Supplemental Security Income over the period 2001-2019. We combine administrative caseload data from the Social Security Administration with state policy changes using two-way fixed-effects methods. We find that RML adoption increases applications for both benefits. However, there is no change in allowances post-RML. We provide suggestive evidence that the observed changes in applications post-RML are driven by increases in marijuana misuse and selective migration, and decreases in unemployment.

Effects of Recreational Marijuana Legalization on College Students: A Longitudinal Study of Attitudes, Intentions, and Use Behaviors

PURPOSE

As legal recreational marijuana use expands rapidly across the U.S., there is growing concern that this will lead to higher rates of use among college-aged young adults. Given the limited research addressing this issue, a longitudinal study was conducted to evaluate the effects of legalizing recreational use on the attitudes, intentions, and marijuana use behaviors of college students in two different legalization contexts, Washington State and Wisconsin.

METHODS

Survey data assessing marijuana attitudes, intentions, and use behavior were collected from 2011 to 2016 on a longitudinal cohort of 338 students at two large public universities in Washington and Wisconsin. Time series analyses were conducted to evaluate postlegalization changes in ever use, 28-day use, and mean attitude and intention-to-use scores in Washington state, using Wisconsin participants as the control group.

RESULTS

Ever use, attitude, and intention-to-use scores did not change significantly more in Washington after legalization than in Wisconsin. However, among prior users, the proportion using in the last 28 days rose faster in Washington after legalization that it did in Wisconsin (p < .001).

CONCLUSIONS

The findings suggest that legalization had the greatest effects on current marijuana users, who are surrounded by a climate that is increasingly supportive of its use.

Seeking safety: a focus group study of young adults' cannabis-related attitudes, and behavior in a state with legalized recreational cannabis

BACKGROUND

Only July 1, 2017, Nevada became the fifth US state to allow the legal sale of recreational cannabis products for adults ages of 21 and over. This study investigates young adults' cannabis-related attitudes, perceptions, and behaviors in a state where recreational and medical cannabis use was recently legalized.

METHODS

We conducted 8 focus groups stratified by cannabis use (regular users, occasional users, and nonusers) with 32 college students ages 18 to 24. Data were analyzed using the inductive qualitative thematic analysis method.

RESULTS

Four themes emerged during analyses: "sort of legal," "mitigating harm through legalization," "Increasing acceptance," and "seeking safety when purchasing cannabis." Despite their limited knowledge of cannabis regulation, the majority of the participants supported recreational cannabis legalization from a harm reduction perspective. Most participants did not believe that cannabis legalization had affected their use behavior. However, participants, especially cannabis users, perceived that recreational cannabis legalization created a context where cannabis use was legally, socially, and behaviorally "safer" than in an illegal context, even for those below the legal age of sale.

CONCLUSIONS

Most studies focus on the role of perceived health risk on cannabis use. If there are population-level long-term effects of recreational cannabis legalization on use behavior, findings suggest that they will be mediated by the perceived legal, social, and behavioral risk of using cannabis.

Self-reported driving after marijuana use in association with medical and recreational marijuana policies

BACKGROUND

A common concern surrounding increasingly permissive marijuana policies in the US is that they will lead to more dangerous behavior, including driving after marijuana use. Although there is considerable research on the effects of marijuana policies on behaviours, few studies have examined self-reported driving after marijuana use. In this study, we use data from the Traffic Safety Culture Index (TSCI) to model self-reported past-year driving after marijuana use in association with medical and recreational marijuana policies.

METHODS

We analysed individual responses to annual administrations of TSCI from years 2013-2017 using a multiple logistic regression model. Our outcome variable was self-reported past-year driving after marijuana use (at least once vs. never), and our primary explanatory variable was the respondents' state medical marijuana (MM) and recreational marijuana (RM) policy. Additional explanatory variables include policies that specify thresholds for marijuana-intoxicated driving, year, and demographic factors.

RESULTS

Drivers in states that legalized MM but not RM had marginally higher odds of self-reporting driving after marijuana use compared to drivers in states where both RM and MM were illegal (adjusted OR 1.29; 95% CI 0.98, 1.70; p = 0.075). However, we found little evidence that drivers in states that legalized both RM and MM had higher odds of driving after marijuana use compared to drivers in states where both RM and MM were illegal (adjusted OR 1.06; 95% CI 0.71, 1.56; p = 0.784). Per-se or THC threshold laws were associated with lower self-reported driving after marijuana use (adjusted OR 0.74; 95% CI 0.57, 0.95; p = 0.018).

CONCLUSION

Although we found some evidence of an association between MM legalization and self-reported driving after marijuana use, our results provide only mixed support for the hypothesis that permissive marijuana policies are associated with higher odds of self-reported driving after marijuana use.

Prevalence and Socio-Demographic, Academic, Health and Lifestyle Predictors of Illicit Drug/s Use among University Undergraduate Students in Finland

Illicit drug/s use (IDU) among university students is a public health concern. We assessed the associations between socio-demographic, academic, and health and lifestyle characteristics (independent variables) and regular, occasional or never IDU (dependent variables). Data were collected across seven faculties (1177 students) at the University of Turku (Finland) via an online questionnaire. About 1.5% of the sample had regular IDU, 19% occasional IDU, and 79% never IDU. Independent predictors of ever (lifetime) IDU included males [adjusted odds ratio (AOR) 1.82, P = 0.001], not living with parents (AOR 2.59, P < 0.001), singles (AOR 0.51, P < 0.001), lower religiosity (AOR 1.49, P = 0.022), better self-rated general health (AOR 0.41, P = 0.003), higher health awareness (AOR 1.93, P = 0.014), more depressive symptoms (AOR 1.82, P = 0.004), daily smokers (AOR 3.69, P < 0.001), heavy episodic drinking (AOR 2.38, P < 0.001) and possible alcohol dependency (AOR 2.55, P < 0.001). We observed no independent associations between ever IDU with age, study discipline, perceived stress or academic performance. The 20.5% ever IDU is concerning. The compelling independent predictors of ever IDU included not living with parents, lower religiosity, daily smokers, heavy episodic drinking and possible alcohol dependency (AOR range 2.38-3.69). Education and prevention need to emphasize the negative consequences to reinforce abstinence from IDU. Health promotion could focus on beliefs and expectations about IDU and target students at risk for successful efforts.

Marijuana use trends among college students in states with and without legalization of recreational use: initial and longer-term changes from 2008 to 2018

BACKGROUND AND AIMS

Young adult college students in the United States are likely to be affected by marijuana liberalization trends. However, changes in students' marijuana use following recreational marijuana legalization (RML) have not been examined in more than one RML state at a time, or beyond 1-2 years post-legalization.

DESIGN

Cross-sectional National College Health Assessment survey administered twice yearly from 2008 to 2018.

SETTING

A total of 587 4-year colleges and universities in 48 US states.

PARTICIPANTS

Undergraduates aged 18-26 years attending college in US states that did (n = 234 669 in seven states) or did not (n = 599 605 in 41 states) enact RML between 2008 and 2018.

MEASUREMENTS

Self-reported marijuana use (past 30 days) and individual and contextual covariates, institution-provided institutional and community covariates and publicly available dates when states enacted RML.

FINDINGS

Adjusting for covariates, state differences and state-specific linear time trends (accounting for pre-RML trends), prevalence of 30-day marijuana use increased more among students exposed to RML [odds ratio (OR) = 1.23, 95% confidence interval (CI) = 1.19-1.28, P < 0.001] than among non-RML state students throughout the same time-period; the results were similar for frequent use (≥ 20 days) (OR = 1.18, 95% CI = 1.10-1.27, P < 0.001). Interaction models supported stronger RML effects among students who were female, residing off-campus and aged 21 years and older; sexual orientation did not moderate RML effects. In the earliest states to enact RML (2012) there were increases in use prevalence in the second through the sixth year post-RML compared to pre-RML. In the second legalization group (2015) there were increases in the first and second year post-RML, and greater increases in the third year. In the later states (2016-17), increases were observed in both years after RML.

CONCLUSIONS

In US states that enacted recreational marijuana legislation from 2012 to 2017 there was evidence for a general trend towards greater increases in marijuana use by college students and differential impact by gender, legal using age and campus residence.

The Spillover Effect of Recreational Marijuana Legalization on Crime: Evidence From Neighboring States of Colorado and Washington State

An ongoing debate exists about the implications of recreational marijuana legalization to public safety. One important public concern is how recreational marijuana legalization may affect crime in neighboring states that have not legalized. Based on Uniform Crime Report (UCR) data from 2003 to 2017, this study used difference-in-differences (DID) analysis to examine the potential spillover effect of recreational marijuana legalization in Colorado and Washington State, with a special focus on the examination of the changes in the rates of a variety of crimes in the border counties of neighboring states relative to the nonborder counties in these states following Colorado’s and Washington’s legalization. Results provide some evidence suggesting a spillover crime reduction effect of legalization, as reflected by the significant decreases in the rates of property crime, larceny, and simple assault in the Colorado region that includes six neighboring states. Results also suggest that the effects of marijuana legalization on crime in neighboring states vary based on crime type and state.

Examining interactions within the theory of planned behavior in the prediction of intentions to engage in cannabis-related driving behaviors

Objective: As marijuana use becomes more available to college students through increasing legal reform, this paper seeks to examine intentions for driving under the influence of cannabis (DUIC) and riding with a high driver (RWHD) through the lens of the theory of planned behavior (TPB) and assess potential interactions between personal attitudes, subjective norms, perceived behavioral control (PBC), and sex. Participants: Undergraduate college students (N = 311) completed online surveys in September, 2013. Method: Participants self-reported their attitudes toward DUIC, subjective norms, PBC, past DUIC and RWHD, and intentions to DUIC and RWHD. Results: Participants' attitudes toward DUIC, subjective norms, and PBC were strongly associated with intentions to DUIC and RWHD bivariately. In regression models, attitudes and PBC were both positively and significantly related to intentions to DUIC and RWHD. Conclusions: DUIC and RWHD are concerns for college populations. Targeting personal attitudes and perceived behavioral control via interventions may reduce these behaviors.

International differences in patterns of cannabis use among adult cigarette smokers: Findings from the 2018 ITC Four Country Smoking and Vaping Survey

BACKGROUND

Although evidence shows that co-use of cigarettes and cannabis is common, there is little research examining if co-use patterns vary depending on the regulatory environment for cannabis. This study examined patterns of co-use and perceptions of relative harm among cigarette smokers in four countries with different histories, and at different stages of cannabis legalization.

METHODS

Data are from the 2018 International Tobacco Control 4CV Survey and included 10035 adult cigarette smokers from Canada, United States (US), Australia, and England. At the time of the survey, Canada and the US had relatively more permissive cannabis regulations compared to Australia and England.

RESULTS

Among this sample of 10035 cigarette smokers, Canada had the highest rate of cannabis co-use in the last 12 months (36.3%), followed by the US (29.1%), England (21.6%), and Australia (21.4%). Among past 12 month co-users (n = 3134), the US (40.2%) and Canada (35.2%) had the highest rates of daily cannabis use, followed by smokers in England (26.3%) and Australia (21.7%); Australian co-users had the highest rate of infrequent (

CONCLUSION

Patterns of tobacco and cannabis co-use differed between countries. Smokers in Canada and the US had higher rates of co-use, daily cannabis use, dual-daily use of both cannabis and cigarettes, and were more likely to perceive smoked cannabis as less harmful than cigarettes compared to England and Australia. Further attention as to how varying cannabis regulations may impact co-use patterns is warranted.

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Key Words

• Cannabis
• Co-use
• Harm Perceptions
• Policy
• Regulation
• Tobacco cigarettes

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MESH Headings Collapse

Grants

• P01 CA200512 NCI NIH HHS

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Affiliation(s)

Shannon Gravely Department of Psychology, University of Waterloo, Waterloo, Canada.
Pete Driezen Department of Psychology, University of Waterloo, Waterloo, Canada; School of Public Health and Health Systems, University of Waterloo, Waterloo, Canada
Danielle M Smith Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, United States
Ron Borland School of Psychological Sciences, University of Melbourne, Melbourne, VIC, Australia; Cancer Council Victoria, Melbourne, VIC, Australia
Eric N Lindblom O'Neill Institute for National & Global Health Law, Georgetown University Law Center, Washington, DC United States
David Hammond School of Public Health and Health Systems, University of Waterloo, Waterloo, Canada
Ann McNeill King's College London, Addictions Department, Institute of Psychiatry, Psychology & Neuroscience, London, United Kingdom; UK Centre for Tobacco & Alcohol Studies, Nottingham, United Kingdom
Andrew Hyland Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, United States
K Michael Cummings Department of Psychiatry & Behavioral Sciences, Medical University of South Carolina, Charleston, United States; Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, United States
Gary Chan Centre for Youth Substance Abuse Research, The University of Queensland, Brisbane, QLD, Australia
Mary E Thompson Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Canada
Christian Boudreau Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, Canada
Nadia Martin Department of Psychology, University of Waterloo, Waterloo, Canada
Janine Ouimet Department of Psychology, University of Waterloo, Waterloo, Canada
Ruth Loewen Department of Psychology, University of Waterloo, Waterloo, Canada
Anne C K Quah Department of Psychology, University of Waterloo, Waterloo, Canada
Maciej L Goniewicz Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, United States
James F Thrasher Department of Health Promotion, Education & Behavior, Arnold School of Public Health, University of South Carolina, Columbia, United States; Tobacco Research Department, Center for Population Health Research, National Institute of Public Health, Cuernavaca, Mexico
Geoffrey T Fong Department of Psychology, University of Waterloo, Waterloo, Canada; School of Public Health and Health Systems, University of Waterloo, Waterloo, Canada; Ontario Institute for Cancer Research, Toronto, Canada

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Guidelines for public health and safety metrics to evaluate the potential harms and benefits of cannabis regulation in Canada

ISSUES

Canada recently introduced a public health-based regulatory framework for non-medical cannabis. This review sought to identify a comprehensive set of indicators to evaluate the public health and safety impact of cannabis regulation in Canada, and to explore the ways in which these indicators may be expected to change in the era of legal non-medical cannabis.

APPROACH

Five scientific databases were searched to compile a list of cannabis-related issues of interest to public health and safety. A set of indicators was developed based on topics and themes that emerged. Preliminary evidence from other jurisdictions in the USA and Canada that have legalised medical and/or non-medical cannabis (e.g. Colorado, Washington) was summarised for each indicator, wherever possible.

KEY FINDINGS

In total, 28 indicators were identified under five broad themes: public safety; cannabis use trends; other substance use trends; cardiovascular and respiratory health; and mental health and cognition. Preliminary trends from other legalised jurisdictions reveal little consensus regarding the effect of cannabis legalisation on public health and safety harms and an emerging body of evidence to support potential benefits (e.g. reductions in opioid use and overdose).

IMPLICATIONS

In addition to indicators of commonly discussed challenges (e.g. cannabis-related hospitalisations, cannabis-impaired driving), this review led to the recommendation of several indicators to monitor for possible public health and safety improvements.

CONCLUSION

In preparing a comprehensive public health and safety monitoring and evaluation system for cannabis regulation, this review underscores the importance of not only measuring the possible risks but also the potential benefits.

Trends in college students' alcohol, nicotine, prescription opioid and other drug use after recreational marijuana legalization: 2008-2018

BACKGROUND

Young adult college students may be particularly sensitive to recreational marijuana legalization (RML). Although evidence indicates the prevalence of marijuana use among college students increased after states instituted RML, there have been few national studies investigating changes in college students' other substance use post-RML.

METHOD

The cross-sectional National College Health Assessment-II survey was administered twice yearly from 2008 to 2018 at four-year colleges and universities. Participants were 18-26 year old undergraduates attending college in states that did (n = 243,160) or did not (n = 624,342) implement RML by 2018. Outcome variables were self-reported nicotine use, binge drinking, illicit drug use, and misuse of prescription stimulants, sedatives, and opioids. Other variables included individual and contextual covariates, and institution-reported institutional and community covariates. Publicly available information was used to code state RML status at each survey administration.

RESULTS

Accounting for state differences and time trends, RML was associated with decreased binge drinking prevalence among college students age 21 and older [OR (95% CI) = 0.91 (0.87 - 0.95), p < .0001] and increased sedative misuse among minors [OR (95% CI) = 1.20 (1.09 - 1.32), p = .0003]. RML did not disrupt secular trends in other substance use.

CONCLUSIONS

In the context of related research showing national increases in college students' marijuana use prevalence and relative increases following state RML, we observed decreases in binge drinking and increases in sedative use that both depended on age. Findings support some specificity in RML-related changes in substance use trends and the importance of individual factors.

Evaluating the impacts of cannabis legalization: The International Cannabis Policy Study

An increasing number of jurisdictions have legalized non-medical cannabis use, including Canada in October 2018 and several US states starting in 2012. The policy measures implemented within these regulated markets differ with respect to product standards, labelling and warnings, public education, retail policies, marketing, and price/taxation. The International Cannabis Policy Study (ICPS) seeks to evaluate the impacts of these policy measures as well as the broader population-level impact of cannabis legalization using a quasi-experimental research design. The objective of this paper is to describe the ICPS conceptual framework, methods, and baseline estimates of cannabis use. The ICPS is a prospective cohort survey conducted with national samples of 16-65-year-olds in Canada and the US. Data are collected via an online survey using the Nielsen Consumer Insights Global Panel. Primary survey domains include: prevalence and patterns of cannabis use; purchasing and price; consumption and product types; commercial retail environment; problematic use and risk behaviours; cannabis knowledge and risk perceptions; and policy-relevant outcomes including exposure to health warnings, public educational campaigns, and advertising and promotion. The first annual wave was conducted in Aug-Oct 2018 with 27,169 respondents in three geographic 'conditions': Canada (n = 10,057), US states that had legalized non-medical cannabis (n = 7,398) and US states in which non-medical cannabis was prohibited (n = 9,714). The ICPS indicates substantial differences in cannabis use in jurisdictions with different regulatory frameworks for cannabis. Future waves of the study will examine changes over time in cannabis use and its effects associated with legalization in Canada and additional US states.

Protocol for a feasibility study investigating the UCalgary's Cannabis Café: education and harm reduction initiative for postsecondary students

INTRODUCTION

High rates of cannabis consumption among emerging adults in Canada represent an important public health issue. As part of the legalisation of cannabis, health objectives were established by the Government of Canada including reducing risky patterns of consumption and cannabis related harm among vulnerable populations. Despite these ambitions, few evidenced based education programmes have been evaluated in the literature. The aim of this study is to describe and evaluate the acceptability of a novel harm reduction and education initiative titled, UCalgary's Cannabis Café. The Cannabis Café incorporates components shown to be effective in reducing risky substance consumption on campuses and substance related stigma. An important objective of the Café is the dissemination of methods to reduce risk in the form of Canada's Lower-Risk Cannabis Use Guidelines.

METHODS AND ANALYSIS

The study will take the form of a non-experimental, observational cohort design, where participants will be asked to complete four surveys (baseline, immediate follow-up, 1 month and 3 months). The primary outcomes of the study will be the feasibility of the initiative including acceptability and implementation. Secondary outcomes include knowledge uptake of methods to reduce risk of cannabis related harm, descriptive cannabis norms and changes in cannabis consumption.

ETHICS AND DISSEMINATION

The study was approved by the University of Calgary Conjoint Health Research Ethics Board (#REB18-1364). The investigators will develop a guideline outlining the Cannabis Café to assist in the replication of this initiative at other locations and publish the results from the study in a peer-reviewed manuscript.