The Efficacy of 90-Minute Versus 60-Minute Sessions of Prolonged Exposure for Posttraumatic Stress Disorder: Design of a Randomized Controlled Trial in Active Duty Military Personnel

Objective: Posttraumatic stress disorder (PTSD) can have devastating effects on multiple aspects of functioning. Thus, it is imperative to increase access to evidence-based treatment for PTSD. Prolonged Exposure therapy (PE) has extensive empirical support and is one of the first-line PTSD treatments included in civilian, veteran, and military clinical practice guidelines. However, the standard 90-min PE session format can constitute a significant barrier to its adoption in routine clinical care settings, which typically schedule 60-min appointment sessions. If the length of PE sessions could be reduced from 90 to 60 min without compromising treatment efficacy and efficiency, this would remove a major barrier to PE adoption. Method: This paper describes the rationale and methods of a randomized controlled noninferiority trial comparing 90-min versus 60-min PE sessions (including 40- vs. 20-min imaginal exposures, respectively) among 160 active duty military personnel with PTSD. The aims of this study are to: (1) examine the efficacy and efficiency (i.e., rate of symptom improvement) of 90- versus 60-min PE; (2) assess change in psychophysiological markers of treatment response across conditions; and (3) test mechanisms of change underlying the efficacy of PE. Results/Conclusions: The results of this study will inform dissemination efforts in military, veteran, and civilian sectors. Further, identifying mechanisms of therapeutic change will answer important theoretical questions about how PE works, in order to refine and increase the efficacy and efficiency of PE to better meet the needs of individuals with PTSD. Clinical Impact Statement Prolonged exposure (PE) therapy is an evidence-based treatment for posttraumatic stress disorder (PTSD) with established efficacy. However, psychotherapy providers often do not use PE with their PTSD patients because PE sessions are 90 min, and most psychotherapy appointments are 60 min. We describe a study that will test whether PE is as effective when delivered in 60-min as compared with the usual 90-min sessions. We also test whether PTSD patients need more 60-min sessions to recover compared with 90-min sessions. Psychotherapy providers who treat PTSD may be more likely to use PE if it can be delivered in 60-min sessions.