Enhanced Skills Training Affective and Interpersonal Regulation (ESTAIR) vs. Treatment as Usual (TAU) for ICD-11 Complex PTSD: A pilot randomized controlled trial (The RESTORE trial)

Abstract: Complex PTSD (CPTSD) is a relatively new condition in the international classification of diseases (ICD-11). Existing research suggests that CPTSD is more common than PTSD. Preliminary evidence also suggests that existing effective therapies for posttraumatic stress disorder (PTSD) such as Cognitive Behavioural Therapy or Eye Movement Desensitisation Therapy might be less effective for CPTSD, highlighting the need for developing and testing new interventions for this debilitating condition. We aimed to establish the feasibility of undertaking a definitive randomized controlled trial to determine the effectiveness of a new modular therapy namely Enhanced Skills in Affective and Interpersonal Regulation (ESTAIR) for CPTSD. This pilot randomized controlled trial aimed to compare a four-module intervention developed to target all symptoms of ICD-11 CPTSD (i.e. ESTAIR) with treatment as usual (TAU) (i.e. psychoeducation and monitoring) in veterans in the UK. ESTAIR is a treatment of cognitive- behavioural orientation that has been developed specifically for CPTSD. It theorises that trauma recovery involves processing memories of traumatic events from the past, but also covers the impact of trauma on the present as it affects current relationships, emotional distress in day-to- day life and quality of life. ESTAIR targets emotion regulation, interpersonal difficulties, negative self-concept, and PTSD symptoms. Participants were eligible if they were UK armed forces veteran adults (18 years or older) in the caseload of a national UK charity, help-seeking for trauma related psychological distress, met diagnostic criteria for CPTSD as measured by the ITQ, and were proficient in the English language. The purpose of the study was to assess feasibility, safety, acceptability and preliminary outcomes at the end of treatment and 3-month follow-up. The International Trauma Questionnaire (ITQ) which measures CPTSD severity was the primary outcome. The trial was pre- registered with ClinicalTrials.Gov (NCT04752072). A total of 56 eligible participants were randomized to either ESTAIR (28 veterans) or TAU (28 veterans). Achievement of enrolment and randomization targets was satisfactory, treatment dropout in both ESTAIR and TAU was low, and study retention was high, all of which supported the feasibility of the study. No serious adverse effects and very few adverse effects occurred, none of which were deemed related to the study. Interviews with the participants indicated that they viewed the treatment duration and structure as satisfactory and the treatment as having a positive impact on multiple dimensions of their lives. ESTAIR provided significantly greater reduction in CPTSD severity across time than the TAU comparator at post- treatment and follow-up. CPTSD pre-to- post effect sizes for ESTAIR were large. Remission1 of probable CPTSD diagnosis at post-treatment was substantially greater in ESTAIR compared to TAU with only 18.2% retaining the diagnosis in ESTAIR versus 84% in TAU. That said, as noted previously, TAU in this instance was limited to psychoeducation and monitoring (as opposed to a therapeutic treatment alternative that would otherwise usually be offered). This may to some degree explain the large differences found between the two treatment arms in this study. Overall, results indicate that ESTAIR is a feasible, safe and acceptable intervention for UK veterans. A further larger trial is required to establish the effectiveness of ESTAIR in veterans with CPTSD, compared to a usual therapeutic treatment alternative, such as Eye Movement Desensitisation Therapy (EMDR) or Cognitive Behavioural Therapy (CBT). The following report describes the aims, background, methods and findings of the study, followed by a discussion of limitations and future directions.