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

The title of this post is the title of this notable new meta-analysis of research on marijuana use by veterans just published in the Clinical Psychology Review and authored by Jasmine Turna and James MacKillop. (I found this preprint version of the paper here for those with paywall barriers.)  Here is the paper's abstract:

Policy changes have resulted in dramatic increases in access to cannabis for medical purposes.  Veterans are disproportionately affected by conditions for which medical cannabis is often pursued, making an evidence-based perspective on risks versus benefits of high priority.  The current review sought to examine the state of the evidence on consequences and correlates of cannabis use among veterans.  Using a comprehensive search strategy, 501 articles were identified and 86 studies met criteria for inclusion. The literature was predominated by cross-sectional studies (67%) of male veterans (71.4%–100% male) from the United States (93.0%). 

Three overarching themes emerged, comprising cannabis associations with other substance use, mental health, and physical health outcomes.  The balance of the evidence associated cannabis use with negative health outcomes, with consistent positive associations with other substance use, psychiatric disorders, and self-harm/suicidality.  Few studies examined the therapeutic effects of cannabis, thus limiting the potential to evaluate evidence of efficacy. 

Priority areas for future research are studies using designs that can examine the directionality of links between cannabis and health in veterans more conclusively, and studies directly examining therapeutic efficacy of cannabis-based therapies in veterans.  Methodologically rigorous design will be essential to inform clinical recommendations and practices guidelines in an era of burgeoning access to cannabis.

Because I have always been eager to support giving veterans safe and healthy access to whatever resources they might need, I am pleased to see added focus on this important issue and a call for further research. And I think it notable that many of the studies examined in this meta-analysis pre-date the modern marijuana reform movement, which leads me to wonder whether some of the negative associations with marijuana use might be linked to its prohibited status rather than the drug itself.