Does Variation in Local Policy Mediate the Impact of Legal Cannabis Markets on Adolescent Cannabis Use?

Background. Studies have found inconsistent evidence for the effects of U.S. state adult-use cannabis legalization on youth cannabis use. However, studies rarely account for the effect of local control  within states on  variation in cannabis access and market development which differentially expose youth to markets and adults who use cannabis. This study fills the gap, by examining the association of retail outlet density, marketing restrictions, taxes and pricing policies, and product restrictions on youth cannabis use in Northern California.

Methods. We use data on 103,134 adolescents aged 13-17 screened for past-year cannabis use during well child visits in Kaiser Permanente Northern California in 2021. Local cannabis policies in effect by January 1, 2021, were collected, as were active cannabis retailers at the time of the adolescent cannabis screening.  Variables specific to bans on local cannabis delivery and storefront retailers, outlet density within a 15-minute driving radius, limits on marketing and products, and tax policies were all constructed. Multivariable logistic regression was used to examine the association of retailer density and local policies with self-reported cannabis use after adjusting for socio-demographics.

Results. Adolescents living in jurisdictions that allowed vs. banned storefront retailers (aOR=1.31; 95% CI: 1.21-1.42) and those exposed to a higher density of retail outlets within a 15-minute drive (aOR for 6+ retailers vs. 0 retailers = 1.30, 95% CI: 1.21-1.39) had higher odds of adolescent cannabis use. Jurisdictions that imposed vs. did not impose taxes, thereby raising the price of cannabis, had lower odds of adolescent cannabis use (aOR: 0.91, 95% CI: 0.84-0.98). Local policies related to marketing and product restrictions were not associated with adolescent cannabis use. 

Conclusions. Retailer bans, less retail availability of cannabis, and local taxation within jurisdictions of California were associated with lower odds of adolescent cannabis use, suggesting that how markets are implemented may be important for understanding impacts on youth. Understanding and capturing information on implementation of legal markets at the local level may be critical for identifying actual health impacts, including youth cannabis use.