The Impact of Recreational Cannabis Legalization on Cannabis Use in U.S. Adults From 2016 to 2023: A Quasi-Experimental Study.

INTRODUCTION

Although cannabis use has increased during a time of expanding cannabis legalization, there is limited evidence on how use has shifted in response to legalization across at-risk groups. This study examined the impact of recreational cannabis legalization on adult cannabis use overall and by demographic and higher-risk strata.

METHODS

Behavioral Risk Factor Surveillance System 2016-2023 surveys (N=859,600 adults from 38 states) were linked to state recreational cannabis legalization. Using quasi-experimental difference-in-differences zero-inflated negative binomial and probit regressions, the impact of legalization on cannabis use was examined overall and by demographic (age, sex, education, race/ethnicity) and higher-risk (mental health, cigarette smoking, alcohol use) strata, adjusting for demographic and policy controls, state, and year. Data were compiled in 2024-2025 and analyzed in 2025.

RESULTS

Recreational cannabis legalization was associated with 44% lower odds of zero cannabis use (95% CI=40%, 48%), indicating higher likelihood of any use, not with a greater frequency of use among users, and a significant total effect estimate, indicating higher cannabis use after legalization. When cannabis use was dichotomized, legalization was associated with a 0.94 percentage point increase in the likelihood of use (95% CI=0.04, 1.84), a 9.8% relative increase compared with 2016 levels. Adults aged ≥60 years, female, White, or college educated had generally lower cannabis use, yet significant interactions (all p<0.1) revealed that they were the most responsive to legalization, with 1-2 percentage point increases in use.

CONCLUSIONS

Recreational cannabis legalization is driving increases in cannabis use among groups with historically lower use rather than increasing use among those who already used cannabis.