Cannabis retail accessibility and adolescent use across a maturing market: Evidence from Canada

The rapid expansion of commercial cannabis retail following legalization in Canada has raised concerns about adolescent cannabis use. This study examined whether spatial accessibility to cannabis retailers was associated with cannabis use among secondary school students.

Repeat cross-sectional data were drawn from the COMPASS study (2018-2023), including 419,887 students across Alberta, British Columbia, Ontario, and Quebec. Student survey data were linked with geospatial measures of cannabis retail accessibility, including distance to nearest retailer, retailer density, and inverse distance weighted density within 2000 m of schools. Multilevel logistic regression models examined associations with ever use, past 12-month use, past 30-day use, and daily/almost daily use. Multilevel ordinal regression assessed use frequency among users. Models adjusted for individual- and school-level covariates, with clustering at the school level.

Cannabis use declined over time, with past 12-month use decreasing from 22.2% in 2018-10.0% in 2023. Associations between spatial accessibility measures and cannabis use outcomes were generally small, inconsistent, and often non-significant. Sensitivity analyses across 264 model specifications supported null effects. Among students who reported cannabis, greater geographic accessibility was associated with higher use frequency in 2018, but this relationship disappeared as retail availability expanded. Perceived ease of access was strongly associated with cannabis use but modestly correlated with retail accessibility.

Spatial accessibility to cannabis retailers was associated with more frequent adolescent cannabis use early in the post-legalization period, but this relationship weakened as retail outlets became widespread. Policies focused on retailer proximity may have limited impact in mature retail markets.