Active Components in Internet-Based Cognitive-Behavioral Therapy for Social Anxiety Disorder: A Randomized Full Factorial Trial

Introduction: Many studies have demonstrated that social anxiety disorder (SAD) can be effectively treated with psychotherapy, particularly cognitive-behavioral therapy (CBT), including internet-based CBT (ICBT). Despite evidencebased treatments, many individuals do not sufficiently benefit from them. Identifying the active components could help improve the effectiveness of SAD treatment. This study tested the effects of four treatment components (psychoeducation, cognitive restructuring, attention training, and exposure) within ICBT for SAD to investigate its active components. Methods: This randomized full factorial trial consisted of four factors (i.e., treatment components) and 16 conditions. A total of 464 adults with a diagnosed SAD were recruited from the community. The primary outcome was SAD symptoms at 8 weeks (post-assessment). Secondary outcomes included SAD diagnosis, SAD symptoms at followup (4 months after post), depression and anxiety symptoms, quality of life, client satisfaction, and adverse effects. Results: Conditions including psychoeducation and exposure were significantly more effective in reducing SAD symptoms at post compared to conditions without these components. Conditions including cognitive restructuring and attention training did not show superiority over conditions without them at post. However, all treatment conditions significantly reduced symptoms compared to the condition without a treatment component. At follow-up, the superiority of psychoeducation and exposure was not significant anymore due to the version without the respective components catching up. Conclusion: The findings suggest that while all treatment components of ICBT for SAD are beneficial compared to no treatment, psychoeducation and exposure include specific active components that significantly improve treatment outcomes more quickly in ICBT for SAD