The impact of Trauma-Focused Cognitive Behaviour Therapy for psychosis on post-traumatic stress symptoms in daily life: ESM outcomes of the STAR Trial.

INTRODUCTION: People with psychosis have high rates of post-traumatic stress-disorder (PTSD). The STAR (Study of Trauma And Recovery) randomised controlled trial found that a Trauma-Focused therapy integrated with Cognitive Behaviour Therapy for psychosis (TF-CBTp) added to Treatment-As-Usual (TAU) reduced PTSD symptoms in people with psychosis compared to TAU only. We hypothesized that TF-CBTp would also reduce PTSD symptoms in daily life, using Experience Sampling Methodology (ESM), which would be associated with improvements on a clinical measure of PTSD. METHODS: Participants were adults with PTSD and schizophrenia-spectrum diagnoses, a subsample of the STAR trial (N=153; TF-CBTp+TAU=73, TAU=80). Participants completed ESM assessments of intrusive memories, hyperarousal, dissociation, avoidance and negative trauma-related cognitions through a smartphone app multiple times daily over six days, at baseline and 9-months post-randomisation (end-of-therapy). RESULTS: No between-group differences were found in ESM measures of momentary PTSD symptoms at 9-months. Significant timepoint×therapy interactions indicated greater decrease over time in hyperarousal, negative cognitions, and avoidance, and in variability of intrusive memories, in TF-CBTp+TAU compared to TAU. ESM measures at 9-months were significantly associated with improvements on the Clinician-Administered PTSD Scale for DSM-5. CONCLUSION: While findings are tentatively in favour of TF-CBTp, the robust reductions in PTSD symptoms found in the STAR trial using retrospective outcome measures were not fully replicated with ESM, suggesting these methodologies may be capturing different features of symptom expression and processes of therapeutic change. Including both approaches in future research could provide a fuller picture of therapy effects on 'in-the-moment' versus reflective reports of experiences.