Background
Mental and other physical health concerns and substance use disorder are common and co-occurring events experienced by US veterans. Treatment with medicinal cannabis is a potential alternative to unwanted medication use for veterans, but more clinical and epidemiologic research is needed to understand the risks and benefits.

Methods
Data were collected from a cross-sectional, self-reported, anonymous survey asking US veterans about their health conditions, medical treatments, demographics, and medicinal cannabis use along with its self-reported effectiveness. In addition to descriptive statistics, logistic regression models were run to examine correlates of the use of cannabis as a substitution for prescription or over-the-counter medications.

Findings
A total of 510 veterans of US military service participated in the survey, which was administered between March 3 and December 31, 2019. The participants reported experiencing a variety of mental and other physical health conditions. Primary health conditions reported included chronic pain (196; 38%), PTSD (131; 26%), anxiety (47; 9%), and depression (26; 5%). Most participants (343; 67%) reported using cannabis daily. Many reported using cannabis to reduce the use of over-the-counter medications (151; 30%) including antidepressants (130; 25%), anti-inflammatories (89; 17%), and other prescription medications. Additionally, 463 veterans (91% of respondents) reported that medical cannabis helped them to experience a greater quality of life and 105 (21%) reported using fewer opioids as a result of their medical cannabis use. Veterans who were Black, who were female, who served in active combat, and who were living with chronic pain were more likely to report a desire to reduce the number of prescription medications they were taking (odds ratios = 2.92, 2.29, 1.79, and 2.30, respectively). Women and individuals who used cannabis daily were more likely to report active use of cannabis to reduce prescription medication use (odds ratios = 3.05 and 2.26).

Implications
Medicinal cannabis use was reported to improve quality of life and reduce unwanted medication use by many of the study participants. The present findings indicate that medicinal cannabis can potentially play a harm-reduction role, helping veterans to use fewer pharmaceutical medications and other substances. Clinicians should be mindful of the potential associations between race, sex, and combat experience and the intentions for and frequency of medicinal cannabis use.