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.

Flavoured tobacco product restrictions in Massachusetts associated with reductions in adolescent cigarette and e-cigarette use.

BACKGROUND: In the USA, many states do not pre-empt municipalities from enacting stricter tobacco-control policies than state or federal laws. Several municipalities in Massachusetts have passed progressive local laws aimed at reducing adolescent tobacco use. We exploited this variability to examine the associations between county-level flavoured tobacco product restrictions, tobacco 21 policies and smoke-free laws prohibiting e-cigarettes with adolescent cigarette and e-cigarette use in Massachusetts, and to assess whether policy effects varied by age. METHODS: We conducted difference-in-differences models to link changes in county-level tobacco-control policies to changes in adolescents' use of cigarettes and e-cigarettes using 2011-2017 biennial Massachusetts Youth Health Surveys. RESULTS: Counties with greater implementation of flavoured tobacco product restrictions were associated with a decrease in the level of cigarette use among users (Coefficient -1.56; 95% CI -2.54 to -0.58). A significant interaction (p=0.03) revealed the largest reductions among 14 and 18 year olds. Increasing flavoured tobacco product restrictions were also associated with reductions in the likelihood of e-cigarette use (Coefficient -0.87; 95% CI -1.68 to -0.06). Increasing tobacco 21 restrictions were associated with decreases in cigarette use only among 18 year olds, while there was no evidence of associations between smoke-free laws with use of either tobacco product. CONCLUSIONS: Adolescents in Massachusetts decreased their use of cigarettes and e-cigarettes in response to local restrictions that limited the sale of flavoured tobacco products to adult-only retail tobacco stores. Local legislation can reduce adolescent tobacco use and municipalities should enact stricter tobacco-control policies when not pre-empted by state law.

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

PURPOSE: Given the rapid expansion of recreational marijuana legalization (RML) polices, it is essential to assess whether such policies are associated with shifts in the use of marijuana and other substances, particularly for adolescents, who are uniquely susceptible to negative repercussions of marijuana use. This analysis seeks to provide greater generalizability, specificity, and methodological rigor than limited prior evidence. METHODS: Youth Risk Behavior Survey data from 47 states from 1999 to 2017 assessed marijuana, alcohol, cigarette, and e-cigarette use among adolescents (14-18+ years; N = 1,077,938). Associations between RML and adolescent past-month substance use were analyzed using quasi-experimental difference-in-differences zero-inflated negative binomial models. RESULTS: Controlling for other state substance policies, year and state fixed effects, and adolescent demographic characteristics, models found that RML was not associated with a significant shift in the likelihood of marijuana use but predicted a small significant decline in the level of marijuana use among users (incidence rate ratio = .844, 95% confidence interval [.720-.989]) and a small increase in the likelihood of any e-cigarette use (odds ratio of zero use = .647, 95% confidence interval [.515-.812]). Patterns did not vary over adolescent age or sex, with minimal differences across racial/ethnic groups. CONCLUSIONS: Results suggest minimal short-term effects of RML on adolescent substance use, with small declines in marijuana use and increase in the likelihood of any e-cigarette use. Given the delayed rollout of commercial marijuana sales in RML states and rapid expansion of RML policies, ongoing assessment of the consequences for adolescent substance use and related health and behavioral repercussions is essential.

A quasi-experimental evaluation of marijuana policies and youth marijuana use.

BACKGROUND: Marijuana use carries risks for adolescents' well-being, making it essential to evaluate effects of recent marijuana policies. OBJECTIVES: This study sought to delineate associations between state-level shifts in decriminalization and medical marijuana laws (MML) and adolescent marijuana use. METHODS: Using data on 861,082 adolescents (14 to 18+ years; 51% female) drawn from 1999 to 2015 state Youth Risk Behavior Surveys (YRBS), difference-in-differences models assessed how decriminalization and MML policy enactment were associated with adolescent marijuana use, controlling for tobacco and alcohol policy shifts, adolescent characteristics, and state and year trends. RESULTS: MML enactment was associated with small significant reductions (OR = 0.911, 95% CI [0.850, 0.975]) of 1.1 percentage points in current marijuana use, with larger significant declines for male, Black, and Hispanic (2.7-3.9 percentage points) adolescents. Effects of MML increased significantly with each year of exposure (OR = 0.980, 95% CI [0.968, 0.992]). In contrast, decriminalization was not associated with significant shifts in use for the sample as a whole, but predicted significant declines in marijuana use among 14-year olds and those of Hispanic and other ancestry (1.7-4.4 percentage points), and significant increases among white adolescents (1.6 percentage points). Neither policy was significantly associated with heavy marijuana use or the frequency of use, suggesting that heavy users may be impervious to such policy signals. CONCLUSION: As the first study to concurrently assess unique effects of multiple marijuana policies, results assuage concerns over potential detrimental effects of more liberal marijuana policies on youth use.