Interactive virtual reality exposure therapy vs metaphor-based VR for social anxiety disorder: Protocol for an active-comparator randomized trial with digital phenotyping.

Introduction: We aim to evaluate the efficacy of interactive virtual reality (VR) therapy for social anxiety disorder (SAD) compared to an active comparator condition. We will also investigate the utility of digital phenotyping as a novel objective assessment tool for monitoring treatment responses. Methods: This single-blind, parallel-group, randomized controlled trial will recruit 100 adults aged 19-40 meeting DSM-5-TR criteria for SAD. Participants will be randomized 1:1 to: (1) an interactive social anxiety-specific VR therapy developed through multidisciplinary collaboration involving psychiatrists, psychologists, service designers, and digital artists; or (2) a metaphor-based VR therapy for generalized anxiety, as an active comparator. Both groups will complete six VR sessions over 3 weeks, administered twice a week. Analysis: The primary efficacy endpoint is change from baseline to post-treatment in social anxiety symptoms, assessed by the Korean version of the Liebowitz Social Anxiety Scale-Self Report (K-LSAS-SR). The Korean Social Avoidance and Distress Scale (K-SADS) and Social Interaction Phobia Scale (K-SIPS) are designated as key secondary endpoints, tested using a pre-specified fixed-sequence hierarchical procedure that preserves the family-wise type I error rate at α = 0.05 without alpha penalty. The secondary outcomes include depressive symptoms, interpersonal competence, and smartphone-derived digital phenotypes (activity, sleep). All assessments will be conducted at baseline, mid-treatment, post-treatment, and at 3-month follow-up. The primary analysis will use a linear mixed-effects model (LMM) to evaluate the group × time interaction at post-treatment. Ethics and dissemination: Approved by the Institutional Review Board of Korea University Anam Hospital (IRB No: 2024AN0537). The results will be disseminated through peer-reviewed publications, academic conferences, and institutional reports. We aim to validate the efficacy of VR therapy and establish digital biomarkers for precision psychiatric approaches to the treatment of SAD.