The availability of medical marijuana dispensary and adolescent marijuana use.

PURPOSE: To examine the association between medical marijuana dispensary (MMD) availability and adolescent marijuana use.

METHODS: The study sample was comprised of 8th, 10th, and 12th graders (N=14,953) from 141 schools in the 2014 Monitoring the Future study, who resided in the 18 states that had legalized medical marijuana as of January 1, 2014. Multilevel logistic regressions with random effects were conducted to quantify the cross-sectional associations of the availability of MMD within 5- and 25-mile buffers from the centroid of school zip codes with self-reported recent use (past-year) and current use (past-month) of marijuana, controlling for individual characteristics and school, zip code, and state contextual factors.

RESULTS: In the combined sample, the availability of MMD was not associated with recent or current use of marijuana. Subsample analyses suggested that the availability within a 5-mile buffer was associated with a higher likelihood of recent use in 8th graders (OR=1.93, 95% CI=1.11-3.33) and the availability within a 5- to 25-mile buffer was associated with a higher likelihood of recent use in 10th graders (OR=1.33, 95% CI=1.00-1.77). The availability of MMD was not associated with recent use in 12th graders or current use in any grades.

CONCLUSIONS: The availability of MMD was not associated with current use of marijuana among adolescents. There was some evidence suggesting that the availability of MMD within short to medium traveling distance may be associated with a higher level of recent use in middle schoolers who are also at a high risk of experimenting with marijuana.