When to Change the Treatment Plan: An Analysis of Diminishing Returns in VA Patients Undergoing Prolonged Exposure and Cognitive Processing Therapy

Evidence-based treatments for posttraumatic stress disorder (PTSD) often produce significant symptom reduction within eight sessions. However, some patients take longer to respond and a better understanding of predictors of later response can help guide treatment. In the current study, the cohort consisted of all VA patients with a PTSD diagnosis who received at least eight sessions of documented evidence based treatment within a 6-month period in FY16-FY17 and had at least two PTSD symptom assessments. We examined the proportion of patients who achieved meaningful change (defined as at least 50% reduction in self-reported PTSD symptoms), both within the first eight sessions and subsequently. Fourteen percent of patients achieved meaningful change within eight sessions and 10% subsequently. Symptom change within the first eight sessions was highly predictive of subsequent change. Those who experienced at least 20% symptom reduction by session eight were twice as likely to subsequently achieve meaningful change as compared with all patients who continued treatment. Patients receiving service-connected disability compensation were less likely and White patients more likely to achieve meaningful change. Without some degree of symptom reduction by session eight, patients are unlikely to achieve meaningful change if treatment is not enhanced or changed.