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Study breakdown

Both cannabis and tobacco use were associated with higher suicide attempt rates among veterans prescribed opioids

Longitudinal CohortStrong evidence
The takeaway

Among over 900,000 veterans on opioids, cannabis use was associated with 11% higher suicide attempt rates, and tobacco with higher rates of attempts, suicide deaths, and overdose deaths.

VA clinicians, pain management specialists, veteran suicide prevention researchers

HR 1.67 for overdose death among tobacco-using veterans on opioids

What the researchers found

Cannabis use: HR 1.11 for suicide attempts. Tobacco: HR 1.18 for attempts, HR 1.19 for suicide deaths, HR 1.67 for overdose deaths. Associations persisted after adjusting for substance use disorders, mental health, and sociodemographics.

Why it matters

Veterans on opioids are already at elevated risk. Identifying cannabis and tobacco as additional risk markers could inform screening and monitoring protocols.

The numbers in context

923,291 veterans. 5.4% cannabis, 39.4% tobacco. Median follow-up 6.7-6.8 years. Cannabis: HR 1.11 suicide attempt. Tobacco: HR 1.18 attempt, HR 1.19 suicide death, HR 1.67 overdose death.

How the study worked

Longitudinal cohort of 923,291 veterans receiving opioid analgesics in VHA clinics (2014-2019) with follow-up through 2021. Cause-specific hazard models adjusted for established suicide/overdose risk factors.

What this study cannot tell us

Observational. Cannabis/tobacco assessed at baseline only. Cannabis associated with attempts, not deaths. Residual confounding possible.

How to read the evidence

Very large national cohort with long follow-up and extensive adjustment, but observational design limits causal claims.

When this study was published

2026 publication using 2014-2021 VA data

The bigger picture

Identifying modifiable or monitorable risk markers could strengthen safety protocols without restricting necessary pain management.

Questions still open

  • Is cannabis use causal or a marker for other risk factors? Would addressing tobacco in opioid-prescribed veterans reduce overdose deaths?

Common questions

Does cannabis cause suicide?
The study found an 11% higher rate of suicide attempts associated with cannabis use after adjusting for mental health conditions, but cannot prove causation.
Why was tobacco more strongly linked to overdose death?
Tobacco was linked to 67% higher overdose death rates. This may reflect shared neurobiological pathways or tobacco as a marker for greater overall substance use severity.

Read the original research

Associations of Cannabis and Tobacco Use with Suicide Attempt, Suicide Death, and Overdose Death Among Veterans Prescribed Opioid Analgesics.

American journal of preventive medicine, 108309

Citation

Nguyen, Nhung; Leonard, Samuel; Byers, Amy L; Austin, Peter C; Krebs, Erin E; Sandbrink, Friedhelm; Bravata, Dawn M; Keyhani, Salomeh. (2026). Associations of Cannabis and Tobacco Use with Suicide Attempt, Suicide Death, and Overdose Death Among Veterans Prescribed Opioid Analgesics.. American journal of preventive medicine, 108309. https://doi.org/10.1016/j.amepre.2026.108309

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