Background: It is unclear whether the evidence-based treatments for PTSD are as effective in patients with CA-PTSD.Objective: We aimed to investigate the effectiveness of three variants of... Show moreBackground: It is unclear whether the evidence-based treatments for PTSD are as effective in patients with CA-PTSD.Objective: We aimed to investigate the effectiveness of three variants of prolonged exposure therapy.Method: We recruited adults with CA-PTSD. Participants were randomly assigned to Prolonged Exposure (PE; 16 sessions in 16 weeks), intensified Prolonged Exposure (iPE; 12 sessions in 4 weeks followed by 2 booster sessions) or a phase-based treatment, in which 8 sessions of PE were preceded by 8 sessions of Skills Training in Affective and Interpersonal Regulation (STAIR+PE; 16 sessions in 16 weeks). Assessments took place in week 0 (baseline), week 4, week 8, week 16 (post-treatment) and at a 6-and 12-month follow-up. The primary outcome was clinician-rated PTSD symptom severity.Results: We randomly assigned 149 patients to PE (48), iPE (51) or STAIR+PE (50). All treatments resulted in large improvements in clinician assessed and self-reported PTSD symptoms from baseline to 1-year follow-up (Cohen's d > 1.6), with no significant differences among treatments. iPE led to faster initial symptom reduction than PE for self-report PTSD symptoms (t(135) = -2.85, p = .005, d = .49) but not clinician-assessed symptoms (t(135) = -1.65, p = .10) and faster initial symptom reduction than STAIR+PE for self-reported (t(135) = -4.11, p < .001, d = .71) and clinician-assessed symptoms (t(135) = -2.77, p = .006, Cohen's d = .48) STAIR+PE did not result in significantly more improvement from baseline to 1-year follow-up on the secondary outcome emotion regulation, interpersonal problems and self-esteem compared to PE and iPE. Dropout rates did not differ significantly between conditions.Conclusions: Variants of exposure therapy are tolerated well and lead to large improvements in patients with CA-PTSD. Intensifying treatment may lead to faster improvement but not to overall better outcomes.The trial is registered at the clinical trial registry, number NCT03194113, Show less
