Preliminary Evaluation of Translated and Culturally-Adapted Internet-Delivered Cognitive Therapy for Social Anxiety Disorder: A Multi-Center, Single-Arm Trial in Japan

Background: Internet-delivered cognitive therapy for social anxiety disorder (iCT-SAD), which is a therapist-guided modular online treatment, has shown strong efficacy and acceptability in English-language randomized controlled trials in the UK and Hong Kong. However, it is not yet known whether iCT-SAD can retain its efficacy following the linguistic translation and cultural adaptation of treatment contents, and implementation in other countries such as Japan. Objective: This study aimed to examine the preliminary efficacy and acceptability of translated and culturally adapted iCT-SAD in Japanese clinical settings. Methods: This multi-center, single-arm trial recruited 15 participants with SAD. At the time of recruitment, participants were receiving usual psychiatric care but had not shown improvement in their social anxiety and required additional treatment. iCT-SAD was provided in combination with usual psychiatric care for 14 weeks (treatment phase), and for a subsequent 3-month follow-up phase that included up to three booster sessions. The primary outcome measure was the self-report version of the Liebowitz Social Anxiety Scale. Secondary outcome measures examined social anxiety-related psychological processes, taijin-kyofusho (fear of offending others), depression, generalized anxiety, and general functioning. The assessment points for the outcome measures were baseline (Week 0), mid-treatment (Week 8), post-treatment (Week 15 [primary outcome assessment point]), and follow-up (Week 26). Acceptability was measured via the dropout rate from the treatment, level of engagement with the program (the rate of module completion), and participants’ feedback about their experience with iCT-SAD. Results: Evaluation of the outcome measures data showed that iCT-SAD led to significant improvements in social anxiety symptoms during the treatment phase (Cohen’s d = 3.66), and these improvements were maintained during the follow-up phase. Similar results were observed for secondary outcome measures. At the end of the treatment phase, 12 participants (80%) demonstrated reliable improvement, and nine (60%) demonstrated remission from social anxiety. One participant (6.6%) dropped out during treatment, and one declined to undertake the follow-up phase after completing treatment. No serious adverse events occurred. On average, participants completed 94.0% of the modules released to them. Participant feedback was positive and highlighted areas of strength in treatment, and included further suggestions to improve suitability for Japanese settings.