KMAN Publication Inc. Quality of Life and Health Sciences 2 Serial Number 3 2026 01 01 The Effectiveness of Acceptance and Commitment Therapy on Experiential Avoidance, Pain Acceptance, and Quality of Life Among Patients With Fibromyalgia The Effectiveness of Acceptance and Commitment Therapy on Experiential Avoidance, Pain Acceptance, and Quality of Life Among Patients With Fibromyalgia 1 14 10.61838/zqt7cz59 EN Journal Article 2025 09 21 <table> <tbody> <tr> <td> <p><strong>Objective:</strong> This study aimed to determine the effectiveness of Acceptance and Commitment Therapy on experiential avoidance, pain acceptance, and quality of life among patients with fibromyalgia.</p> <p><strong>Methods and Materials: </strong>This quasi-experimental study was conducted using a pretest–posttest design with a control group and a two-month follow-up period. The statistical population consisted of patients with fibromyalgia who referred to rheumatology and pain management clinics in Tehran. A total of 40 patients were selected through purposive sampling and assigned to an experimental group and a control group, with 20 participants in each group. The experimental group received Acceptance and Commitment Therapy in eight weekly sessions of approximately 90 minutes, while the control group received no psychological intervention during the same period and continued routine medical care. Data were collected using the Acceptance and Action Questionnaire-II, the Chronic Pain Acceptance Questionnaire, and the World Health Organization Quality of Life Questionnaire-BREF. Data were analyzed using repeated-measures analysis of variance and Bonferroni post hoc tests in SPSS software.</p> <p><strong>Findings: </strong>The results showed significant time, group, and time × group interaction effects for experiential avoidance, pain acceptance, and quality of life. Repeated-measures analysis of variance indicated that Acceptance and Commitment Therapy significantly reduced experiential avoidance in the experimental group compared with the control group (p &lt; 0.001). The intervention also significantly increased pain acceptance among participants in the experimental group (p &lt; 0.001). In addition, quality of life improved significantly after the intervention compared with the control group (p &lt; 0.001). Bonferroni post hoc comparisons showed significant differences between pretest and posttest and between pretest and follow-up for all three variables, while the differences between posttest and follow-up were not significant, indicating the stability of treatment effects over time.</p> </td> </tr> </tbody> </table> <p><strong>Conclusion: </strong>Acceptance and Commitment Therapy was effective in reducing experiential avoidance, increasing pain acceptance, and improving quality of life among patients with fibromyalgia, and its effects remained stable at the two-month follow-up.</p> https://journals.kmanpub.com/index.php/qlhs/article/download/5781/10970