Effectiveness of Acceptance Commitment Therapy in Social Anxiety Disorder: Application of a Longitudinal Method to Evaluate the Mediating Role of Acceptance, Cognitive Fusion, and Values.

Introduction: The aim of the present study was to examine the effectiveness of acceptance and commitment therapy (ACT) on symptom severity, fear of negative evaluation, quality of life (QoL), and the mediating role of acceptance, cognitive fusion, and value among patients with social anxiety disorder (SAD). Methods: Thirty patients diagnosed with SAD were randomized in the intervention (n=15) or waiting list groups (n=15). The social phobia and Anxiety inventory (SPAI), brief fear of negative evaluation scale (BFNE), World Health Organization quality of life (WHOQoL) scale, social anxiety-acceptance and action questionnaire (SA-AAQ), cognitive fusion questionnaire (CFQ), and valued living questionnaire (VLQ) were administered before, immediately after, and at a one-month follow-up. Repeated measurement design was used in the intervention group to investigate the changes of mediation and outcomes variables in the pre-test, during treatment, and post-test. Twenty-four patients completed the study. Data were analyzed using one-way analysis of covariance (ANCOVA), multivariate analysis of covariance (MANCOVA), and repeated measurements. Results: There were significant differences between the intervention and waiting list groups in the severity of symptoms (P=0.001), fear of negative evaluation (P=0.002), and QoL (P=0.03), as well as in terms of specific measures of SA-AAQ (P=0.001), cognitive fusion (P=0.001), an important section of VLQ (P=0.001). Repeated measurement results showed that acceptance and action of social anxiety and cognitive fusion had a mediating role in the severity of social anxiety, fear of negative evaluation, and QoL. Conclusion: The results indicated the effectiveness of ACT for SAD and highlighted the mediator role of social anxiety, acceptance and action, and cognitive fusion in the severity of SAD. Highlights: This study evaluated effectiveness of acceptance commitment therapy(ACT) on social anxiety disorders (SAD).This study evaluated mechanisms of change of ACT in SAD.ACT has effectiveness for SAD.Acceptance and action and cognitive fusion have mediator role in SAD. Plain Language Summary: Social anxiety disorder (SAD) is one of the most psychiatric disorders. Although CBT has been effective for SAD, most patients continue to demonstrate residual symptoms and impairment after treatment. Over the past several years, a third-wave behavioral therapy has been developed within behavioral and cognitive approaches. Some researchers suggest a new generation of psychotherapists termed acceptance and commitment therapy (ACT) that has many evidence in SAD. However, studies have not examined the mechanism of change of ACT in SAD using methods and proper instruments.in the present study ACT have effectiveness for SAD. In addition to, acceptance and action and cognitive fusion have mediator role in SAD.