rethinkTHC Search
Menu
Study breakdown

Cannabis Alone Did Not Raise Suicide Risk in Veterans, but Combined with Heavy Drinking It Did

Cross SectionalModerate evidence
The takeaway

Among 1,098 US veterans, cannabis use alone was not linked to higher suicidal ideation, but combining cannabis with hazardous drinking was associated with the greatest risk for suicidal behavior.

VA clinicians, veteran mental health providers, suicide prevention researchers, substance use counselors

What the researchers found

Veterans who used both cannabis and alcohol hazardously had greater odds of suicidal ideation and elevated suicide risk than any other group, including those who used either substance alone. Notably, cannabis use alone was not associated with greater odds of suicidal ideation or elevated suicide risk compared to the non-using group. However, cannabis use (alone or with alcohol) was associated with higher rates of non-suicidal self-injury (NSSI).

Why it matters

The nuanced finding that cannabis alone did not increase suicide risk while combined use did suggests that polysubstance use patterns, not individual substances in isolation, may drive the most concerning outcomes in veteran populations.

The numbers in context

1,098 veterans; 78% male; concurrent use (HD+CU) had greatest odds of suicidal ideation and elevated suicide risk; CU alone: no elevated suicide risk; both CU only and HD+CU associated with higher NSSI rates

How the study worked

Cross-sectional survey of 1,098 US veterans (78% male, 67% White). Compared four groups: hazardous drinking only, cannabis use only, concurrent use, and neither. Assessed past-year suicidal ideation, elevated risk for suicidal behavior, and past-year NSSI via validated questionnaires, controlling for covariates.

What this study cannot tell us

Cross-sectional design cannot establish causation. Self-report survey may undercount sensitive behaviors. Predominantly male, White sample may not generalize to all veterans. Could not assess cannabis use frequency, quantity, or type.

How to read the evidence

Moderate: adequate sample size with multivariate adjustment, but cross-sectional design and self-report limitations.

When this study was published

2025 publication

The bigger picture

Veteran suicide prevention efforts typically focus on alcohol and mental health treatment. This data suggests concurrent cannabis and alcohol use deserves specific clinical attention as a risk marker, while cannabis alone may carry different risk profiles for different types of self-harm.

Questions still open

  • What mechanisms make concurrent cannabis and alcohol use particularly risky for suicidal behavior?
  • Why is cannabis use associated with NSSI but not suicidal ideation when used alone?

Read the original research

Hazardous Drinking and Cannabis Use in Military Veterans: Comparative Associations with Risk for Suicidal and Non-Suicidal Self-Injury.

International journal of mental health and addiction

Citation

Grove, Jeremy L; Beckham, Jean C; Calhoun, Patrick S; Dedert, Eric A; Pugh, Mary J; Kimbrel, Nathan A. (2025). Hazardous Drinking and Cannabis Use in Military Veterans: Comparative Associations with Risk for Suicidal and Non-Suicidal Self-Injury.. International journal of mental health and addiction. https://doi.org/10.1007/s11469-025-01453-x

Explore the wider topic