The Effects of Cannabis Access Laws on Sleep in the U.S.

Introduction: The global average sleep duration has declined significantly, with substantial health and economic consequences. Given the increasing legalization of cannabis for medical and recreational use, this study examines the association between cannabis access laws and sleep duration in the U.S. Methods: A two-way-fixed-effects difference-in-differences regression was used to analyze the impact of medical and recreational cannabis laws on sleep duration. Data were drawn from the American Time Use Survey, including 175,493 respondents aged 18-65 years from 2003 to 2021. Subgroup analyses were performed on sex and age groups. Analyses were conducted in 2024. Results: Recreational cannabis laws were associated with an average reduction in sleep of 5.37 minutes per night (99% CI=0.91, 9.83), whereas medical cannabis laws had no significant effect on sleep duration. Recreational cannabis laws were associated with individuals falling asleep 7.14 minutes later (99% CI=3.12, 11.16) with no change in wake-up times, and only the eating and drinking category of time use was significantly affected, with an increase of 1.90 minutes. These findings were concentrated in males and those aged ≥25 years. Conclusions: The implementation of recreational cannabis laws has a negative effect on sleep duration, highlighting the need for further research on the broad impacts of cannabis access on health.