A Randomized Controlled Trial of Group-Based Acceptance and Commitment Therapy for Major Depressive Disorder

Major depressive disorder (MDD) is a prevalent and debilitating psychiatric condition. This study developed a group-based acceptance and commitment therapy (GACT) program for MDD and conducted a randomized controlled trial to evaluate its effectiveness. The study aims to assess the effects of GACT and identify factors influencing depression recovery in patients with MDD in Korea.

Individuals diagnosed with MDD, aged 18-40 years, were recruited. Fifty-nine participants were randomly assigned to either the GACT or waitlist control (WLC) group, with 50 participants (27 in GACT and 23 in WLC) successfully completing the program.

The GACT group demonstrated significant improvements in depression symptoms (Center for Epidemiological Studies-Depression Scale, CES-D), rumination (Ruminative Response Scale-Revised, RRS-R), experiential avoidance (Acceptance and Action Questionnaire-II, AAQ-II), and cognitive fusion (Cognitive Fusion Questionnaire, CFQ) compared to the WLC group (all ps<0.05). Correlation and multivariate regression analyses indicated that improvements in CES-D scores were associated with changes in AAQ-II scores.

Our findings suggest that the 8-week GACT program has positive effects on depressive symptoms and ACT-related psychological processes in patients with MDD. This study highlights GACT as a promising group-based intervention for depression, potentially reducing the burden of individual psychological treatments.