Recreational Marijuana Laws and suicide deaths in the US

Abstract

Objectives: This study aimed to examine the association between Recreational Marijuana Laws (RMLs) and age-adjusted suicide rates in the U.S. population from 2000 to 2022.

Methods: Suicide rate data were obtained from the Centers for Disease Control and Prevention's (CDC) Multiple Cause of Death Files at the state and year level. Information on RML status and years of legalization was sourced from the National Organization for the Reform of Marijuana Laws (NORML). Using a staggered difference-in-differences (DiD) framework, we assessed the relationship between RMLs and age-adjusted suicide rates.

Results: RMLs were associated with an increase of 0.68 suicide deaths per 100,000 population (p-value < 0.05). This increase was primarily driven by states that implemented RMLs in 2018 (Maine, Vermont, and Michigan) and 2019 (Illinois). In contrast, states that enacted RMLs in 2015 (Alaska, Oregon, and Washington, D.C.) experienced a decline in suicide deaths post-legalization.

Conclusion: This study adds to the growing body of literature on RMLs and suicidality by underscoring the potential role of state-specific factors-such as demographic characteristics, implementation strategies, or contextual differences-in shaping the direction and magnitude of this association. These findings highlight the need for further research to better understand the mechanisms underlying these divergent outcomes.