Trauma-focused therapies for post-traumatic stress in psychosis: study protocol for the RE.PROCESS randomized controlled trial

Introduction: Many people with psychotic disorders experience symptoms of post-traumatic stress disorder (PTSD). In recent years, several trauma-focused therapies (TFTs), including cognitive restructuring (CR), prolonged exposure (PE), and eye movement desensitization and reprocessing (EMDR) have been studied and found to be safe and effective in reducing PTSD symptoms in individuals with psychosis. However, studies were conducted in different countries, with varying inclusion criteria, therapy duration, control groups, and trial outcomes. RE.PROCESS will be the first study to compare the impact of CR, PE, and EMDR with a waiting list control condition within the same context. Methods and analysis: This is the protocol of a pragmatic, single-blind, multicentre, superiority randomized controlled trial, in which CR, PE, and EMDR are compared to a waiting list control condition for TFT (WL) in a naturalistic treatment setting. Inclusion criteria are as follows: age ≥ 16 years; meeting full DSM-5 diagnostic criteria for PTSD on the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5), with a total CAPS score ≥ 23; and a psychotic disorder in the schizophrenia spectrum confirmed by the Structured Clinical Interview for DSM-5 (SCID-5). Participants (N=200) will be randomly allocated to 16 sessions of one of the TFTs or WL, in addition to receiving treatment as usual (TAU) for psychosis. The primary objective is to compare the effects of CR, PE, and EMDR to WL on researcher-rated severity of PTSD symptoms over time from baseline to 6-month follow-up. Secondary objectives are to examine these effects at the separate time-points (i.e., mid-treatment, post-treatment, and at 6-month follow-up) and to test the effects for clinician-rated presence of PTSD diagnosis, and self-rated severity of (complex) PTSD symptoms. Discussion: This is the first RCT to directly compare the effects of CR, PE, and EMDR within the same context to TAU on PTSD symptoms in individuals with psychosis and PTSD. Secondary effects on clinical and functional outcomes will be investigated both directly after therapy and long term. Trial registration: ISRCTN ISRCTN56150327. Registered 18 June 2019.