Testing a variable-length Cognitive Processing Therapy intervention for posttraumatic stress disorder in active duty military: Design and methodology of a clinical trial

Combat-related trauma exposures have been associated with increased risk for posttraumatic stress disorder (PTSD) and comorbid mental health conditions. Cognitive Processing Therapy (CPT) is a 12-session manualized cognitive-behavioral therapy that has emerged as one of the leading evidence-based treatments for combat-related PTSD among military personnel and veterans. However, rates of remission have been less in both veterans and active duty military personnel compared to civilians, suggesting that studies are needed to identify strategies to improve upon outcomes in veterans of military combat. There is existing evidence that varying the number of sessions in the CPT protocol based on patient response to treatment improves outcomes in civilians. This paper describes the rationale, design, and methodology of a clinical trial examining a variable-length CPT intervention in a treatment-seeking active duty sample with PTSD to determine if some service members would benefit from a longer or shorter dose of treatment, and to identify predictors of length of treatment response to reach good end-state functioning. In addition to individual demographic and trauma-related variables, the trial is designed to evaluate factors related to internalizing/externalizing personality traits, neuropsychological measures of cognitive functioning, and biological markers as predictors of treatment response. This study attempts to develop a personalized approach to achieving positive treatment outcomes for service members suffering from PTSD. Determining predictors of treatment response can help to develop an adaptable treatment regimen that returns the greatest number of service members to full functioning in the shortest amount of time.