Substance use and posttraumatic stress disorders: symptom interplay and effects on outcome.

This study examined concurrent and prospective associations between substance use disorder (SUD) and posttraumatic stress disorder (PTSD) diagnosis and symptoms and mechanisms underlying these associations. Participants (n = 133) were assessed at intake and 6 months following inpatient SUD treatment. Patients differed by baseline PTSD status on psychiatric comorbidity and substance use history but not on current substance use symptoms. Participants with alcohol use disorders reported a greater number of reexperiencing symptoms. Baseline PTSD status did not predict substance use outcome. However, change in PTSD status over follow-up predicted substance use outcomes; those with unremitted PTSD demonstrated poorer SUD outcome than those with remitted PTSD. General psychiatric distress at follow-up was associated with poorer outcomes, and such distress mediated the association between PTSD change status and substance use outcome. Findings suggest that clinicians should assess for PTSD among those with SUD and, during treatment, should monitor PTSD and other psychological symptoms, which may be risk factors for relapse to substance abuse.