Cannabis Use Linked to Higher Odds of Suicide Death in National Case-Control Study | Research

The takeaway

After adjusting for alcohol and demographics, cannabis use was associated with 83% increased odds of suicide death in a national dataset.

public-health researchers, policymakers evaluating cannabis legalization, suicide prevention professionals

What the researchers found

Toxicology-verified cannabis use was associated with 83% increased odds of suicide (aOR 1.83, 95% CI: 1.36-2.31), independent of alcohol use, which showed a 20-fold increase in suicide odds.

Why it matters

Most research on cannabis and suicide focuses on ideation or attempts. This study directly examined completed suicide deaths using toxicological verification rather than self-report, addressing a significant gap in the literature.

The numbers in context

17.1% of suicide cases tested positive for THC compared to 7.2% of controls. Cannabis aOR for suicide: 1.83. Alcohol aOR for suicide: 20.53. Other risk factors included male sex, White race, ages 35-49, and less than high school education.

How the study worked

Case-control study using 2013 National Violent Death Reporting System suicide decedents as cases and 2013 NSDUH respondents as controls, with data fusion from the 2013 National Roadside Survey to correct for self-report misclassification. Weighted multivariable logistic regression estimated adjusted odds ratios.

What this study cannot tell us

Cross-sectional case-control design prevents causal conclusions. Controls were from a general population survey while cases were suicide decedents, creating potential selection bias. Mental health conditions were not included as covariates. THC positivity indicates recent use but not frequency or dose.

How to read the evidence

Large national datasets with toxicological verification strengthen the findings, but the case-control design, potential confounders, and inability to establish causation limit evidence to moderate.

When this study was published

Uses 2013 data from three national databases.

The bigger picture

While this study found an association between cannabis use and suicide, the cross-sectional design cannot establish causation. The alcohol association was dramatically larger (20-fold vs. 83%), and unmeasured confounders like mental health diagnoses were not fully accounted for.

Questions still open

Does the association hold when controlling for diagnosed mental health conditions?
What role does frequency and dose of cannabis use play in suicide risk?

Common questions

Does this prove cannabis causes suicide?

No. This is a case-control study showing an association, not causation. Unmeasured factors like mental health diagnoses could explain some of the relationship.

How does the cannabis risk compare to alcohol?

Alcohol showed a dramatically larger association with suicide (20-fold increased odds) compared to cannabis (83% increased odds).

Read the original research

Cannabis use and suicide: a case-control study based on integrative data analysis.

Journal of cannabis research, 7(1), 93

View on PubMed ↗Publisher’s paper ↗

Citation

Shi, Qiongyu; Li, Guohua. (2025). Cannabis use and suicide: a case-control study based on integrative data analysis.. Journal of cannabis research, 7(1), 93. https://doi.org/10.1186/s42238-025-00352-1