The impact of posttraumatic stress disorder on cannabis quit success

Background: Though a growing number of US Veterans are being diagnosed with cannabis use disorders, with posttraumatic stress disorder (PTSD) observed as the most frequently co-occurring psychiatric disorder among this population, no research has investigated the impact of PTSD diagnosis on cannabis quit success. Objectives: The present study sought to determine the impact of PTSD on cannabis use following a self-guided quit attempt. Methods: Participants included 104, primarily male, cannabis-dependent US Veterans (M-age = 50.90 years, SDage = 9.90). The study design was prospective and included an assessment immediately prior to the quit attempt, and assessments weekly for the first 4 weeks post-quit, and then monthly through 6 months post-quit. Results: Results indicated that PTSD diagnosis was not associated with time to first lapse or relapse. However, individuals with PTSD used more cannabis at baseline and evidenced a slower initial decline in cannabis use immediately following the quit attempt. All findings were significant after accounting for alcohol and tobacco use across the cessation period, as well as co-occurring mood and anxiety disorder diagnoses. Conclusion: Findings highlight the potential utility of interventions for individuals with cannabis use disorder and co-occurring PTSD, particularly early in a cessation attempt.