The problem of dropout from "gold standard" PTSD therapies

Understanding of posttraumatic stress disorder (PTSD) has increased substantially in the past several decades. There is now more awareness of the many different types of trauma that can lead to PTSD, greater refinement of diagnostic criteria, and the development and testing of various treatments for it. As implementation of PTSD therapies has increased, there is also increased attention to the key issues of retention and dropout. Retention refers to the percentage of patients who stay in a treatment for its intended dose, and dropout is the opposite (the percentage who leave prior to the intended dose); both of which have major implications for treatment outcomes. The two PTSD therapies most studied in relation to retention and dropout are Prolonged Exposure and Cognitive Processing Therapy, which have been the subject of massive, formal, multi-year dissemination roll-outs. Both of these evidence-based treatments are defined as gold-standard therapies for PTSD and showed positive outcomes and reasonable retention of patients in randomized controlled trials (RCTs). But an emerging picture based on real-world practice indicates substantial dropout. Such real-world studies are distinct from RCTs, which have consistently evidenced far lower dropout rates, but under much more restricted conditions (e.g. a more selective range of patients and clinicians). In this paper, the phenomena of retention and dropout are described based on real-world studies of Prolonged Exposure and Cognitive Processing Therapy, including rates, characteristics of patients, clinicians, and programs in relation to retention and dropout, and identification of clinical issues and future research on these topics. It is suggested that the term "gold-standard" evidence-based treatments should be reserved for treatments that evidence both positive results in RCTs but also feasibility and strong retention in real-world settings.