Acceptance and commitment group therapy for chronic pain and transdiagnostic mental health problems : feasibility and effectiveness of a replicated single-case design

Abstract

The aim of this study was to assess the efficacy of group-based Acceptance and Commitment Therapy (ACT-G) on individuals with chronic pain and common mental disorders. Also, exploring potential differences in treatment outcomes between the two groups. The study included a sample of 61 participants aged 28 to 65 (M = 46.5, SD = 10.4) currently undergoing rehabilitation at VIRK, with a female-to-male ratio of 76.6% (N = 49) to 23.4% (N = 15). The participants completed an online questionnaire twice prior to treatment. These measures established a baseline. The study consisted of six groups, three for each condition, with eight ACT-related treatment measures administered after baseline. Also, two questionnaires were administered during the first and last treatment sessions: the Clinical Outcomes in Routine Evaluation-Outcome Measure (CORE-OM) and the Pain Catastrophizing Scale (PCS). The results revealed that ACT group therapy impacted both groups, with no significant differences in treatment outcomes between groups. Additionally, statistical analyses demonstrated significant differences in CORE-OM and PCS scores after treatment. However, it is noteworthy that neither group achieved the threshold for reliable change nor fell below the established cut-off score on the CORE-OM.Keywords: Acceptance and Commitment Therapy, group therapy, common mental disorders, chronic pain, psychological flexibility, cognitive fusion, values