The role of distress tolerance in treatment of posttraumatic stress and substance use disorders: a systematic review.

Comorbid posttraumatic stress disorder and substance use disorder (PTSD-SUD) is associated with more severe symptoms, higher treatment dropout, and worse treatment outcomes than either condition alone. Distress tolerance (DT) is a potentially modifiable risk factor of PTSD and SUD that may impact treatment outcomes. However, little is known about changes in or impact of DT on comorbid PTSD-SUD treatment. This review identified treatment outcome studies of adult samples with SUD and diagnosis or symptoms of comorbid PTSD that examined the assessment of DT and its effects on treatment. Eight articles representing seven unique studies were included. No study included DT-specific interventions for PTSD and/or SUD, and only three examined change in DT over the course of treatment. Most studies examined DT as a predictor of premature treatment discontinuation or a baseline predictor of treatment outcomes. Though DT was not a robust predictor of treatment discontinuation and results were inconsistent on SUD outcomes, lower levels of DT predicted slower or less symptom improvement in PTSD. Future work should address DT in comorbid PTSD-SUD, identify active ingredients of current empirically supported treatments for PTSD and/or SUD, and incorporate additional DT skills into existing treatments, particularly for clients with low DT.