Habituation of Distress and Craving During Treatment as Predictors of Change in PTSD Symptoms and Substance Use Severity

Objective: Increasing evidence supports the efficacy of trauma-focused exposure therapy in the treatment of posttraumatic stress disorder (PTSD) and co-occurring substance use disorders. Little is known, however, about the mechanisms of change in treatment for patients with PTSD and co-occurring substance use disorders. The aim of the present study was to examine whether within- and between-session habituation of distress and substance craving during imaginal exposure relates to treatment outcomes among U.S. military veterans with PTSD and a co-occurring substance use disorder (N = 54). Method: Veterans received Concurrent Treatment of PTSD and Substance Use Disorders Using Prolonged Exposure, a manualized integrated treatment combining prolonged exposure with cognitive-behavioral therapy for substance use disorders as part of a larger randomized clinical trial. Self-reported distress and craving ratings were collected during each imaginal exposure session. Results: Data were analyzed using a series of random intercept and slope multilevel linear and generalized linear models. Results revealed that between-session habituation of distress and craving was associated with greater improvement in PTSD symptoms during treatment. Between-session habituation of craving was also associated with a marginally greater reduction in frequency of substance use among participants still reporting use during treatment. Within-session habituation of distress was unrelated to treatment outcome. Conclusion: Together, these findings indicate that habituation in both distress and craving may be important in maximizing treatment outcome for patients with PTSD and comorbid substance use disorders. What is the public health significance of this article? This study highlights the importance of repeatedly measuring distress and substance craving during exposure to memories of traumatic events during trauma-focused treatments among Veterans with co-occurring post traumatic stress disorder (PTSD) and substance abuse. Improvements in distress across treatment sessions predicts better treatment response for PTSD symptoms, while improvements in craving predicts better treatment response for both PTSD symptoms and substance abuse. To maximize gains in treatment, it may be important to focus on monitoring improvement in distress and craving changes.