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

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).

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.

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.

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.

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.