Cannabis Use in Veterans Is Mostly Linked to Negative Health Outcomes | Research

The takeaway

A comprehensive review of 86 studies found cannabis use in military veterans was consistently associated with other substance use, psychiatric disorders, and self-harm/suicidality, with very few studies examining therapeutic benefits.

Veterans health providers, military health researchers, cannabis policy advocates

Cannabis in veterans was consistently associated with psychiatric disorders and self-harm across 86 studies

What the researchers found

Across 86 included studies, cannabis use in veterans was consistently associated with other substance use, psychiatric disorders, and self-harm/suicidality. The literature was dominated by cross-sectional designs (67%) of predominantly male U.S. veterans, with very few studies examining cannabis as therapy.

Why it matters

Veterans disproportionately suffer from conditions like PTSD and chronic pain that drive cannabis use, yet the evidence base for therapeutic benefit is remarkably thin compared to evidence of associations with negative outcomes.

The numbers in context

501 articles identified; 86 met criteria; 67% cross-sectional; 71.4-100% male; 93% from U.S.; consistent associations with other substance use, psychiatric disorders, and self-harm/suicidality; few therapeutic efficacy studies.

How the study worked

Comprehensive review of 86 studies from 501 identified articles examining correlates and consequences of cannabis use among military veterans, using systematic search strategies.

What this study cannot tell us

Predominance of cross-sectional designs prevents causal conclusions; heavily male U.S. veteran samples limit generalizability; lack of therapeutic efficacy studies creates an incomplete picture; selection bias in study populations.

How to read the evidence

Comprehensive review with systematic search, limited by the predominance of cross-sectional, observational designs in the underlying literature.

When this study was published

Published in 2021.

The bigger picture

The significant imbalance between evidence of harms and evidence of benefits does not necessarily mean cannabis is harmful for veterans; it may reflect research priorities and funding patterns that have favored studying negative associations over therapeutic potential.

Questions still open

Would well-designed clinical trials of cannabis therapies for veteran-specific conditions change the evidence balance? Does cannabis use cause psychiatric problems in veterans or do psychiatric problems drive cannabis use?

Common questions

Is cannabis safe for veterans?

This review found cannabis use was consistently associated with negative outcomes including other substance use, psychiatric disorders, and self-harm in veterans. However, very few studies have tested whether cannabis therapies actually help with veteran-specific conditions.

Does cannabis help with PTSD in veterans?

The review found almost no rigorous studies testing cannabis as therapy for veterans. The evidence linking cannabis to negative outcomes largely comes from observational studies that cannot determine which came first: the cannabis use or the health problems.

Read the original research

Cannabis use among military veterans: A great deal to gain or lose?

Clinical psychology review, 84, 101958

View on PubMed ↗Publisher’s paper ↗

Citation

Turna, Jasmine; MacKillop, James. (2021). Cannabis use among military veterans: A great deal to gain or lose?. Clinical psychology review, 84, 101958. https://doi.org/10.1016/j.cpr.2021.101958