Guided internet-based cognitive behavioral therapy for obsessive-compulsive disorder: A multicenter randomized controlled trial in Japan

Few studies have compared the effectiveness of internet-based cognitive behavior therapy (ICBT) for obsessive-compulsive disorder (OCD) with treatment as usual (TAU). We investigated the effectiveness of guided ICBT for patients with OCD. This prospective, randomized, controlled, assessor-blinded, multicenter clinical trial was conducted at three facilities in Japan from January 2020 to March 2021. Thirty-one patients with OCD as the primary diagnosis participated in the trial and were randomly assigned to either the intervention group or the control group. The primary outcome was the Yale–Brown obsessive-compulsive scale score; the assessors were blinded. Results of the analysis of covariance among the groups were significantly different between the groups (p < 0.01, effect size Cohen's d = 1.05), indicating the superiority of guided ICBT. The results suggest that guided ICBT is more effective than TAU for treating OCD. RCT REGISTRATION: UMIN Clinical Trials Registry (UMIN000039375).