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

The goal of this clinical trial is to learn about the efficacy and cost-effectiveness of stepped-care Internet-based cognitive behavioral therapy (SC-ICBT) compared with Cognitive Behavioral Group Therapy (CBGT) and conventional medical treatment (treatment as usual, TAU) in adults with obsessive-compulsive disorder (OCD) in China.

The main questions it aims to answer are:

question 1: Whether the efficacy of SC-ICBT is noninferior to CBGT and TAU for OCD?

question 2: Whether SC-ICBT is more cost-effective than CBGT and TAU for OCD?

Participants will receive treatment (SC-ICBT or CBGT or TAU) for 6 weeks.

Prior to the main study, we conduct a non-randomized pilot study to explore the efficacy and cost-effectiveness of SC-ICBT related to CBGT for adults with OCD in China.

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.

Eligibility Criteria:
Inclusion Criteria:

1. Age between 18 and 50 years
2. Satisfied with the diagnostic criteria for OCD in DSM-5.
3. 16≤YBOCS score ≤31
4. Taking medication stably for 8 weeks
5. Education level ⩾6 years
6. Has sufficient audiovisual skills to complete the necessary examinations for the study.
7. Right-handed (this criterion is for fMRI subjects only)
8. Subjects and their guardians understood the study and signed informed consent.

Exclusion Criteria:

1. Satisfied with the diagnostic criteria for a mental disorder in DSM-V other than OCD.
2. Obsessive-compulsive symptoms were too severe to participate in the experiment.
3. High risk of suicide.
4. Severe central system or physical disease
5. Pregnant women or women that getting ready for being pregnant and lactating.
6. Other treatments being performed.
7. Uncooperative or unable to complete treatment
8. With metal implants in the body, such as pacemakers, intracranial silver clips, metal dentures, arterial stents, arterial clips, joint metal fixation, or other metal implants, etc. (this criterion is for fMRI subjects only)