Cannabis legalization linked to unexpected surge in smoking rates

Several U.S. states have passed recreational cannabis legalization laws that permit adult use, possession, cultivation, sharing, and retail (dispensary) sales of cannabis. Considering the variability in cannabis laws across states and that cannabis use is associated with cigarette smoking, state-specific analyses of the impact of recreational cannabis legalization laws on cigarette smoking are needed. The authors examined changes in cigarette smoking prevalence in Virginia after the passage of a recreational cannabis legalization law in April 2021 that permitted adult use, possession, sharing, and cultivation of cannabis but not retail dispensary sales. This cross-sectional study utilized data from 992,615 participants aged ≥18 years from the Behavioral Risk Factor Surveillance System survey conducted annually from 2015 to 2023. The authors used a difference-in-differences method to compare cigarette smoking prevalence in Virginia before (January 1, 2015-April 28, 2021) and after (May 1, 2021-December 31, 2023) the passage of its recreational cannabis legalization law with that in 15 states that did not pass any recreational cannabis legalization law as of December 2023. The analysis accounted for sociodemographic characteristics, state-specific time-varying and time-invariant factors, seasonality, and confounders that are common across states but change over time. After the passage of recreational cannabis legalization law, the probability of smoking cigarettes in Virginia, in relation to that in comparison states, increased by 1.4 percentage points (95% CI=0.27, 2.60; p=0.02). This estimate was equivalent to a 9.5% relative increase in smoking prevalence over the prerecreational cannabis legalization law level of 15.1%. Stratified analyses by specific sociodemographic groups indicated that, in Virginia compared with comparison states, smoking prevalence increased by 10.2% among males, 64.3% among Hispanics, 19.9% among persons whose education is high school level or lower, and 14.7% among people aged 21-49 years. In contrast, a 61.6% decrease was observed among young adults aged 18-21 years who were not eligible to use recreational cannabis under Virginia's recreational cannabis legalization law. Stronger tobacco control measures and integration with cannabis regulations may be needed in Virginia to mitigate increases in cigarette smoking prevalence associated with passage of the recreational cannabis legalization law.