Effect of SC-ICBT for Adults With OCD：A Three-Arm Randomized Controlled Trial

Internet-based cognitive behavioral therapy (ICBT) integrates the Internet and cognitive behavioral therapy, which enables patients to participate in different treatment modules online. ICBT has been proved to be an effective way to improve the symptoms of OCD patients with lower cost. Stepped care model (SCM) allows to better balance the efficacy of treatment and the cost of treatment. In the main study, the investigators plan to develop an intervention pattern of stepped-care Internet-Based cognitive behavioral therapy (SC-ICBT): After individualized assessment（0 week and 3 week separately）, OCD patients will be provided with self-guided ICBT or therapist-guided ICBT through the severity of their symptoms flexibly. This study will be a randomized, controlled, assessor-blinded trial of three groups in OCD: Stepped-care Internet-based Cognitive Behavioral Therapy (SC-ICBT) combined with medication, Cognitive Behavioral Group Therapy (CBGT) combined with medication, and conventional medical treatment (TAU). The study aims to investigate the efficacy and cost-effectiveness of SC-ICBT related to CBGT and TAU for adults with OCD in China. To initially validate the feasibility of SC-ICBT in Chinese patients with OCD, the investigators plan to firstly conduct a small, non-randomized pilot study prior to the main study. In the pilot study, patients assigned to SC-ICBT group will begin with self-guided ICBT, followed by an assessment of their treatment outcomes at week 3, with non-responders being escalated to a higher intensity of treatment, and additional therapist-guided ICBT in the following three weeks. In the main study, the investigators plan to recruit 114 OCD patients and randomly assigns them to the SC-ICBT group, CBGT group, and TAU group for treatment of 6 weeks and follow-up of 3 months. While in the pilot study, 46 OCD patients will be recruited and assigned to the SC-ICBT group or CBGT group based on their autonomous will. Questionnaires, scales, behavior experiments and other experimental materials will be used to evaluate the intervention effect of 6-week SC-ICBT on obsessive and compulsive symptoms, cognitive function and quality of life of OCD patients as well as patients' and therapists' cost.