Feasibility of Guided Internet-Based Cognitive Behavioral Therapy for Panic Disorder and Social Anxiety Disorder in Japan: Pilot Single-Arm Trial

Background: Cognitive behavioral therapy (CBT) is effective in treating anxiety disorders. Accessibility to CBT has been limited in Japan due to the shortage of therapists. While an open -source e -learning system can be used to create a simple internet-based cognitive behavioral therapy (ICBT) program, the safety and outpatient acceptance of this treatment approach have not been explored in Japan. Objective: The aim of this study was to investigate whether outpatients with anxiety disorders could accept and successfully complete the ICBT program with guidance by CBT therapists when implementing therapeutic modules and CBT tasks. Due to being in the initial phase of a novel treatment in Japan, this study was intended for verification with a small sample size. Methods: In total, 6 adults, including 4 male participants and 2 female participants, were enrolled in a single -arm trial. The intervention involved guided ICBT comprising 12 sessions, including CBT text, comprehension confirmation tests, and explanatory videos about cognitive behavioral models, accessible through a website. The therapist guided the participants in accessing the ICBT program and answering their questions using a chat tool. The primary outcome was anxiety severity assessed using the State -Trait Anxiety Inventory -Trait. Secondary outcomes included the Panic Disorder Severity Scale, Liebowitz Social Anxiety Scale (LSAS), Beck Anxiety Inventory (BAI), Patient Health Questionnaire-9, Generalized Anxiety Disorder-7, and Working Alliance Inventory-Short Form (WAI-SF). Statistical analyses were performed using paired 2 -tailed t tests to assess the changes in clinical symptoms. The total WAI-SF score at the final session was used to evaluate the therapeutic alliance. For statistical analyses, mean changes for total State -Trait Anxiety Inventory -Trait, BAI, Panic Disorder Severity Scale, LSAS, Patient Health Questionnaire-9, and Generalized Anxiety Disorder-7 scores were analyzed using the paired 2 -tailed t test. The 2 -sided significance level for hypothesis testing was set at 5%, and 2 -sided 95% CIs were calculated. Results: Most participants diligently engaged with the ICBT program. No adverse events were reported. The mean total scores for the primary outcome decreased by 11.0 (SD 9.6) points (95% CI -22.2 to 0.20; Hedges g=0.95), but it was not statistically significant. The mean total scores for the secondary outcomes that assess clinical symptoms decreased, with a significant reduction observed in the BAI of 15.7 (SD 12.1) points (95% CI -28.4 to -3.0; P=.03; Hedges g=1.24). The mean total scores for PDSS and LSAS decreased significantly, by 12.0 (SD 4.24) points (95% CI -50.1 to 26.1; P=.16; Hedges g=1.79) and 32.4 (SD 11.1) points (95% CI -59.7 to -4.3; P=.04; Hedges g=1.38), respectively. Of the participants, 67% (n=4) showed treatment response, and 50% (n=3) achieved remission after the intervention. The therapeutic alliance, measured using the WAI-SF, was moderate. Conclusions: Guided ICBT may be feasible for the treatment of outpatients with panic disorder and social anxiety disorder in Japan.