Medical Cannabis Laws and Adolescent Alcohol Use Initiation

BACKGROUND. The effects of medical cannabis laws (MCLs) on adolescent alcohol use remains unclear. Previous literature investigates alcohol consumption rather than alcohol initiation among adolescents, and does not examine the effect by sociodemographic characteristics and state-level dispensary status. We used population representative, state-level data to examine the relationship between MCLs and adolescent alcohol initiation. METHODS. Data for this study were derived from the Youth Risk Behavior Survey (YRBS), a nationally representative, cross-sectional school-based survey administered by the Centers for Disease Control (CDC) in odd-numbered years from 1991 to 2015. We used a difference-in-difference model to assess pre and post effects of state MCL enactment on adolescent alcohol use initiation. Logistic regression analyses assessed associations between MCLs and varying ages of initiation. We further stratified our results by race/ethnicity, gender, and dispensary status. RESULTS. Results from adjusted logistic regression models showed higher odds of initiating alcohol among adolescents in states without MCLs when compared to adolescents in states with MCLs (OR 1.37, [95% CI = 1.29, 1.44]). This effect was consistent across age, race/ethnicity, and gender groups. Reductions in self-report of alcohol initiation were also consistently found in multiple age strata (9-10, 11-12, and 13-14), though this finding did not reach conventional levels of statistical detection in all race/ethnicities. CONCLUSIONS. Our findings support a substitutive effect, suggesting that adolescents in states with MCLs, as opposed to states without MCLs, may substitute cannabis for alcohol. Considering the evolving landscape of medical cannabis laws and the proliferation of state-level legalization laws, further research into the effects of such policies, such as adult-use cannabis laws, is warranted to further elucidate their effects on adolescent substance use.