The impact of intensive trauma-focused treatment on adults with PTSD and ASD traits: a pre-post intervention study

Background: Post-traumatic stress disorder (PTSD) often co-occurs with elevated autism spectrum disorder (ASD) traits, potentially affecting treatment response. Empirical data on the impact of ASD traits on the effectiveness of trauma-focused therapy remain scarce. Objective: To investigate the treatment response following intensive trauma-focused therapy in patients with PTSD, comparing outcomes between individuals with high versus low comorbid ASD traits. Methods: 175 patients with PTSD underwent an intensive trauma-focused treatment programme that integrated prolonged exposure, EMDR therapy, psychoeducation and physical activities. Participants were categorised into a high ASD trait group (n = 70) and a low ASD trait group (n = 105) based on scores on the AQ-50. PTSD symptoms were measured pre- and post-treatment using the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5). A mixed model repeated measures ANOVA was used to analyze the interaction between time and group on CAPS-5 scores. Results: Both groups showed significant reduction in PTSD symptoms following treatment, with large effect sizes (Cohen’s d = 2.89 in the low ASD group and 3.07 in the high ASD group). Overall, 83% of patients lost their PTSD diagnosis post-treatment. A significant decrease in AQ-50 scores was observed in the high ASD traits group with a medium effect size (Cohen’s d =.52), while 31% of these patients shifted to the low ASD traits group after treatment. Reliable clinical improvement in PTSD symptoms was observed in 93% of patients with high ASD traits and 90% of those with low ASD traits. No adverse events or treatment dropouts occurred. Conclusions: Intensive trauma-focused treatment was found effective and safe for patients with PTSD, including those with elevated ASD traits. The results suggest that presence of high ASD traits does not preclude substantial treatment gains or loss of diagnosis, and underscore the relevance of inclusive, tailored trauma-focused therapy approaches for neurodiverse populations.