Acceptance and Commitment Therapy in Chronic Low Back Pain and Comorbid Depression: A Single-Case Study with Idiographic Network Analysis

This study analyzed the efficacy of acceptance and commitment therapy (ACT) in six individuals with chronic low back pain plus depressive symptoms using an idiographic approach within a randomized controlled trial. Daily ecological momentary assessments (EMA) and full assessments at baseline, posttreatment, and follow-up were collected. Outcomes included pain interference, pain intensity, and depressed mood, and the process variable was psychological inflexibility. Analyses involved visual inspection, non-overlap of all pairs, Tau, Tau-U, and idiographic network analysis. Moderate improvements were observed in pain interference (5/6), depressed mood (5/6), and psychological inflexibility (3/6), with limited change in pain intensity (1/6). Most participants (4/6) reported an overall relevant improvement. Idiographic networks showed considerable variability across participants, with psychological inflexibility and depressed mood playing a central role. Findings suggest ACT may help reduce pain interference and depressed mood, highlighting the need for personalized approaches and the continued use of single-case methods combined with EMA.