Heterogeneity of state medical marijuana laws and adolescent recent use of alcohol and marijuana: Analysis of 45 states, 1991–2011

Abstract

Objective: To assess associations between enactment of state medical marijuana laws (MMLs), MML restrictiveness, and past-30-day youth alcohol use overall, and in relation to marijuana use. Method: This quasi-experimental difference-in-difference designed study used state-level Youth Risk Behavior Survey data of 9th–12th grade students in 45 states from 1991–2011 (N D 715,014). We conducted bivariate (unadjusted) and multivariable (adjusted for state, year, individual characteristics) logistic regression analyses to examine the effect of MML enactment (yes/no) and less restrictive vs. more restrictive MMLs on five varying measures of past 30-day alcohol use (i.e., any use or binge) and alcohol and marijuana use behaviors. Results: In the final adjusted analyses, MML enactment was associated with lower odds of adolescent past 30-day (1) alcohol use (OR D 0.92, [0.87, 0.97], p