Cannabis Dependence Was Strongly Linked to Suicide Attempts in Iraq/Afghanistan Veterans | Research

The takeaway

Among 319 Iraq/Afghanistan-era veterans, lifetime cannabis dependence was associated with nearly 8-fold increased odds of post-deployment suicide attempts, even after controlling for PTSD, depression, pain, and other substance use.

VA clinicians, veteran mental health providers, military suicide prevention researchers.

Cannabis dependence was associated with 8-fold increased odds of suicide attempts (AOR=7.963), even after controlling for PTSD and depression.

What the researchers found

Lifetime cannabis dependence was significantly associated with post-deployment suicide attempts (AOR=7.963, p=.014) after controlling for pre-deployment suicide attempts, PTSD, depression, pain, non-cannabis substance use disorder, and gender. This is the first evidence that heavy cannabis use may be a unique risk factor for suicide in veterans.

Why it matters

Veteran suicide is a public health crisis. While some veterans use cannabis to self-medicate PTSD and pain, this study suggests cannabis dependence (not casual use) may independently increase suicide risk, complicating the risk-benefit calculation.

The numbers in context

319 veterans studied. Cannabis dependence associated with AOR=7.963 for post-deployment suicide attempts (p=.014). Controlled for pre-deployment attempts, PTSD, depression, pain, other substance use, and gender.

How the study worked

Retrospective analysis of 319 veterans deployed to Iraq or Afghanistan. Structured clinical interviews and self-report questionnaires assessed cannabis dependence, suicide attempts, PTSD, depression, pain, and other substance use.

What this study cannot tell us

Retrospective design with recall bias. Relatively small sample. Cannot determine causation. Cannabis dependence may be a marker for severity of underlying conditions. Self-selected veteran sample may not be representative.

How to read the evidence

Moderate - controlled for key confounders including pre-deployment attempts, but retrospective design and relatively small sample.

When this study was published

Published in 2019.

The bigger picture

This finding creates tension with the growing movement to provide veterans access to medical cannabis for PTSD. While cannabis may help some symptoms, this study suggests that heavy use progressing to dependence could increase suicide risk.

Questions still open

Does cannabis dependence cause suicide risk or merely mark more severe mental health problems? Would medical cannabis programs with monitoring prevent dependence and associated risks? Is the risk specific to dependence or present at lower use levels?

Common questions

Does cannabis increase suicide risk in veterans?

This study found cannabis dependence (not casual use) was associated with nearly 8-fold increased odds of post-deployment suicide attempts, even after accounting for PTSD, depression, pain, and other substance use. However, the study cannot prove causation.

Should veterans with PTSD use cannabis?

This study raises a caution: while cannabis may help some PTSD symptoms, progressing to cannabis dependence was strongly associated with suicide risk. The authors suggest heavy cannabis use may be a unique risk factor that warrants monitoring.

Read the original research

Cannabis Use Disorder and Post-Deployment Suicide Attempts in Iraq/Afghanistan-Era Veterans.

Archives of suicide research : official journal of the International Academy for Suicide Research, 23(4), 678-687

View on PubMed ↗Publisher’s paper ↗

Citation

Adkisson, Kelsie; Cunningham, Katherine C; Dedert, Eric A; Dennis, Michelle F; Calhoun, Patrick S; Elbogen, Eric B; Beckham, Jean C; Kimbrel, Nathan A. (2019). Cannabis Use Disorder and Post-Deployment Suicide Attempts in Iraq/Afghanistan-Era Veterans.. Archives of suicide research : official journal of the International Academy for Suicide Research, 23(4), 678-687. https://doi.org/10.1080/13811118.2018.1488638