Longitudinal Course of Mental Health Symptoms Among Veterans With and Without Cannabis Use Disorder

Public Health Significance Statement This study indicates that returning veterans with a diagnosis of cannabis use disorder (CUD) report worse depression, anxiety, posttraumatic stress disorder (PTSD), alcohol use, and psychosocial functioning. Findings also indicate that CUD was associated with more severe and persistent alcohol use and PTSD symptom severity long term. This information may be immediately useful for assessment and treatment planning purposes, prevention, and could inform much needed research efforts to examine the long-term effects of CUD on the mental health of returning veterans. Objective: Cannabis use disorder (CUD) is the most common non-alcohol related substance use disorder (SUD) in the United States and is especially prevalent among returning veterans. The long-term mental health correlates of CUD remain unknown, which is significant given the rise in legalization and also recreational and medicinal cannabis use nationally. Method: Using a gender-balanced, national sample of 1,649 veterans (n = 115 with CUD; 75.2% White; M (age) = 37.49, SD = 9.88), we used latent growth curve modeling to examine posttraumatic stress disorder (PTSD) symptom severity, depressive symptoms, generalized anxiety, alcohol use, and psychosocial functioning between veterans with versus without a prior diagnosis of CUD over five time points, spanning an average of 7 years. Results: Returning veterans with CUD compared to those without reported higher alcohol use, depression, anxiety, PTSD symptom severity, and worse psychosocial functioning at baseline. We observed nonlinear change across each outcome. We also found that CUD moderated change in alcohol use (quadratic: b = -.129, p < .001) and PTSD symptoms (quadratic: b = -.280, p = .019), such that individuals with CUD evidenced decelerated change and worse outcomes relative to veterans without a previously documented CUD diagnosis. Trajectories of depression, anxiety, and psychosocial functioning were similar across individuals with versus without CUD. Conclusions: In the first long-term and longitudinal evaluation of mental health and alcohol use course among returning veterans, CUD was associated with worse and more persistent alcohol use and PTSD symptom severity over time. These data have implications for clinical assessment, case conceptualization, and treatment of veterans and may inform efforts to offset risk for hazardous drinking and PTSD following a diagnosis of CUD.

Automated summary

Returning veterans diagnosed with cannabis use disorder (CUD) showed higher levels of depression, anxiety, PTSD, alcohol use, and worse psychosocial functioning compared to those without the diagnosis. CUD was also associated with more severe and persistent alcohol use and PTSD symptom severity over the long term.