A randomized controlled trial of group-based acceptance and commitment therapy for obsessive-compulsive disorder

In recent years, acceptance and commitment therapy (ACT) has become one of the most promising developments in the treatment of obsessive-compulsive disorder (OCD). Although cumulative evidence supporting the efficacy of individual ACT as a therapeutic intervention for OCD has been reported, research on the efficacy of group ACT (GACT) remains insufficient. In this study, 72 patients with OCD were randomly assigned equally to the GACT intervention and wait-list control (WLC) groups, and an 8-week program was administered to the GACT group. The symptoms and process measures of the GACT group (N = 34) were compared with those of the WLC group (N = 31) at pre-treatment, post-treatment, and the 8-week follow-up. The Yale-Brown Obsessive-Compulsive Scale scores indicated that GACT had a moderate and significant impact on reducing obsessive-compulsive (OC) symptoms over the treatment period. This continued through to the 8-week follow-up, which resulted in a 39.3% reduction in symptoms, whereas the WLC group did not show any improvement. Process measures, such as psychological flexibility and cognitive fusion, showed significant improvements only in the GACT group. Additionally, changes in cognitive fusion scores were significantly associated with changes in the OC symptoms. These findings support the efficacy of GACT as a treatment for OCD particularly by reducing OC symptoms through cognitive defusion. Our results provide crucial preliminary findings that can serve as a cornerstone for verifying the effectiveness of GACT in OCD treatment.