Recreational Cannabis Laws Were Linked to a Small Increase in Suicide Deaths, But Results Varied by State
Recreational marijuana laws were associated with an increase of 0.68 suicide deaths per 100,000 population overall, but the effect varied dramatically by state, with some early-adopting states actually seeing decreases.
Quick Facts
What This Study Found
RMLs were associated with a statistically significant increase of 0.68 suicide deaths per 100,000 population overall. The increase was primarily driven by states legalizing in 2018 (Maine, Vermont, Michigan) and 2019 (Illinois). In contrast, states that enacted RMLs in 2015 (Alaska, Oregon, Washington D.C.) experienced a decline in suicide deaths post-legalization.
Key Numbers
Overall RML effect: +0.68 suicide deaths per 100,000 (p<0.05); 2018 and 2019 legalizing states drove the increase; 2015 legalizing states (Alaska, Oregon, DC) saw decreases; data from 2000-2022; staggered DiD framework.
How They Did This
Staggered difference-in-differences analysis of state-level age-adjusted suicide rates from CDC Multiple Cause of Death Files (2000-2022), using RML implementation dates from NORML to compare suicide trends in states before and after legalization.
Why This Research Matters
The divergent results across states suggest that the relationship between cannabis legalization and suicide is not straightforward. State-specific factors, including how legalization is implemented, demographic characteristics, and mental health infrastructure, may be more important than legalization itself.
The Bigger Picture
This study adds nuance to the cannabis-suicide literature by showing that the direction and magnitude of the association depend heavily on which states are examined. This heterogeneity suggests that factors beyond cannabis access, such as implementation strategies and local context, shape outcomes.
What This Study Doesn't Tell Us
Ecological study design (state-level data) cannot establish individual-level causation. Cannot control for all state-level confounders that changed alongside legalization. The COVID-19 pandemic overlapped with several states' legalization periods. Small number of states in each legalization cohort limits statistical power.
Questions This Raises
- ?What specific state-level factors explain the divergent suicide trends?
- ?Did the COVID-19 pandemic confound the results for later-legalizing states?
- ?Would individual-level data show different patterns than state-level ecological analysis?
Trust & Context
- Key Stat:
- Suicide trends post-legalization varied dramatically: some states saw increases, others saw decreases
- Evidence Grade:
- Moderate: Rigorous staggered difference-in-differences design using two decades of data, though ecological design and state-level heterogeneity complicate interpretation.
- Study Age:
- Published in 2025 with data from 2000-2022.
- Original Title:
- Recreational Marijuana Laws and suicide deaths in the US.
- Published In:
- Psychiatry research, 345, 116386 (2025)
- Authors:
- Nayeem, Nawar(3), Messias, Erick(5), Lin, Ping-I(5)
- Database ID:
- RTHC-07244
Evidence Hierarchy
Looks back at existing records to find patterns.
What do these levels mean? →Frequently Asked Questions
Why did some states see suicide increases and others decreases after legalization?
The study could not determine the specific reasons. Possible explanations include differences in implementation strategies, existing mental health infrastructure, demographic characteristics, concurrent policy changes, and timing relative to the COVID-19 pandemic.
Does cannabis legalization cause suicide?
This ecological study found a statistical association at the state level, but cannot prove causation. The dramatically different outcomes across states suggest that legalization itself is not the primary driver and that context-specific factors play a larger role.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-07244APA
Nayeem, Nawar; Messias, Erick; Lin, Ping-I. (2025). Recreational Marijuana Laws and suicide deaths in the US.. Psychiatry research, 345, 116386. https://doi.org/10.1016/j.psychres.2025.116386
MLA
Nayeem, Nawar, et al. "Recreational Marijuana Laws and suicide deaths in the US.." Psychiatry research, 2025. https://doi.org/10.1016/j.psychres.2025.116386
RethinkTHC
RethinkTHC Research Database. "Recreational Marijuana Laws and suicide deaths in the US." RTHC-07244. Retrieved from https://rethinkthc.com/research/nayeem-2025-recreational-marijuana-laws-and
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.