Online Radical Acceptance Intervention for Social Anxiety Disorder: a Randomized Controlled Trial

This randomized controlled trial will evaluate a self-guided online Radical Acceptance intervention for adults with Social Anxiety Disorder. The intervention is adapted from Dialectical Behavior Therapy (DBT) and is designed to help individuals notice and accept difficult thoughts and feelings that arise during social situations. The study will compare this program with an active control condition that provides training in relaxation skills, also adapted from DBT, which focus on physiological strategies for reducing acute emotional arousal.

The study will enroll 100 adults diagnosed with Social Anxiety Disorder. All study activities take place online. After eligibility is confirmed through structured diagnostic interviews, participants will complete a baseline learning session followed by six home practice sessions delivered over a two-week period. Participants in both conditions will receive culturally adapted video-based training followed by a brief debriefing to ensure understanding and correct application of the assigned skill.

The trial is designed to examine changes in social anxiety symptoms over time and to compare the effects of Radical Acceptance and relaxation skills training. In addition to symptom outcomes, the study will assess several proposed mechanisms of change. These mechanisms include interpretation bias and emotion regulation flexibility measured through behavioral tasks, as well as experiential avoidance, rumination, and difficulties in emotion regulation measured through self-report instruments. Mechanism assessments will be completed at baseline and after the fourth practice session. Participants will also report their momentary positive and negative emotions before and after each practice session.

Recruitment will occur through online advertisements. Screening includes an online questionnaire followed by a telephone interview and a video-based diagnostic assessment using the ADIS-5 and selected DIAMOND modules, administered by trained graduate students. Eligible individuals will provide informed consent for both the assessment session and the intervention phase of the study.

Participants will be randomly assigned by an automated algorithm to one of the two study conditions. All assessments and intervention procedures will be completed remotely. The study includes follow-up assessments at three weeks and three months after the intervention to evaluate the stability of treatment effects.