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.