Massed prolonged exposure for posttraumatic stress disorder among individuals in comprehensive substance use treatment: Study protocol for a randomized controlled trial.

Posttraumatic stress disorder (PTSD) and substance use disorders (SUDs) often co-occur and are associated with a more severe clinical profile than either disorder alone. Prolonged Exposure (PE) is empirically supported treatment for PTSD and has demonstrated effectiveness among those with a co-occurring SUD. However, PE is not typically offered in substance use treatment settings, in part due to concerns about feasibility, retention, and symptom exacerbation, as well as structural misfit with time-limited residential and outpatient programs. Massed Prolonged Exposure (M-PE), PE delivered multiple times per week and completed within a condensed timeframe, yields comparable treatment outcomes to PE and may better align with the structure of residential and outpatient care and address key barriers to implementation. Here, we describe an ongoing randomized controlled trial investigating the efficacy of M-PE versus trauma treatment as usual (TAU) delivered concurrent to SUD TAU, among individuals with co-occurring PTSD and substance use disorders enrolled in a comprehensive residential and outpatient SUD program. In addition to examining treatment outcomes, this trial utilizes qualitative methods to gain a deeper understanding of participants' experiences and evaluate M-PE implementation barriers and facilitators in an SUD treatment setting. We describe the development and implementation of this randomized clinical trial.