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.

Conclusions—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.

Document Type


Publication Date


Notes/Citation Information

Published in Journal of Consulting and Clinical Psychology, v. 85, no. 3, p. 274-281.

© American Psychological Association, 2017. This paper is not the copy of record and may not exactly replicate the authoritative document published in the APA journal. Please do not copy or cite without author's permission. The final article is available, upon publication, at: https://doi.org/10.1037/ccp0000180

The copyright holder has granted the permission for posting the article here.

The document available for download is the authors' post-peer-review final draft of the article.

Digital Object Identifier (DOI)


Funding Information

The authors would like to acknowledge support from NIDA grant number DA030143 (Back, S.E.), the Department of Veteran Affairs Clinical Sciences Research and Development Career Development Award CX000845 (PI: Gros), and resources at the Ralph H. Johnson VAMC.