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

Effect of Stepped Care in Internet-Based Cognitive Behavioral Therapy for Adults With Obsessive-Compulsive Disorder：A Three-Arm Randomized Controlled Trial

This study aims to investigate the efficacy and cost-effectiveness of SC-ICBT related to CBGT and TAU 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. In the study, the investigators plan to develop an intervention pattern of stepped care in 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 the obsessive-compulsive disorder: Stepped Care in 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. 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 in the study. 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.

Obsessive-Compulsive Disorder, Stepped Care in Internet-based Cognitive Behavioral Therapy, Cost-effectiveness, Randomized Controlled Trial

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 while they will continue with the medications they already have.

OCD patients will be provided with therapist-guided offline Cognitive Behavioral Group Therapy while they will continue with the medications they already have.

OCD patients will be treated as usual. Namely, they will continue with the medications they already have.

OCD patients will take part in four structured online lessons for 6 weeks. Lesson one: Psychological Health Education, including the knowledge about OCD, SUDs and other related information. Lesson two: Exposure and Response Prevention (ERP), including the knowledge about ERP, exposure item list and other related information. Lesson three: Practice of Exposure and Response Prevention. Patients are asked to perform ERP practice based on what they have learned previously: practise at least once a day, a day about one hour all together. On this basis, patients with severe obsessive and compulsive symptoms(Y-BOCS≥24) will be provided with extra therapist-guided ICBT: twice a week, about an hour one time. Lesson four: Practice retrospection and relapse prevention.

OCD patients will be asked to come to Shanghai Mental Health Center to take part in the offline CBT group. Each group will be treated for 6 weeks, twice a week for 2 hours each time. The treatment was supervised by an experienced CBGT therapist.

In this study, the investigators use selective serotonin reuptake inhibitors (SSRIs) approved by the State Food and Drug Administration (CFDA) for the treatment of OCD (i.e., fluoxetine, paroxetine, sertraline, and fluvoxamine). The maximum dosage shall not exceed the maximum dosage prescribed in the instruction manual.

YBOCS is compiled by Goodman in the United States and contains 10 items to assess the severity of obsessive thoughts and compulsive behavior. The scoring method adopts a five-point scale of 0-4 points, and the total score range is 0-40 points, which has good reliability and validity.

FOCI, a self-rating scale, is used to assess the severity of obsessive-compulsive symptoms within one month, which contains 20 items. The first 15 items are evaluated the symptoms by yes and no, and the last 5 items are evaluated the severity of symptoms on 0-4 five-point scale.

Self-rating Depression Scale (SDS) was developed by William W. K. Zung of Duke University Medical School in 1965. It is one of the most widely used self-rating depression scales. It is used to measure the severity of depression and its change in treatment.

The Self-rating Anxiety Scale (SAS) is very similar to the Self-rating Depression Scale (SDS) from the scale construction to the evaluation method. It is a very simple clinical tool to analyze the subjective anxiety symptoms of patients. It is suitable for adults with anxiety symptoms and has a wide range of application.

36-item Short Form Health Survey（SF-36）will be used to assess the health-related quality of life of patients. SF-36 is one of the most commonly used standardized measurement tools for quality of life in the world, including eight subscales, a total of 36 items, involving physical and mental health.

The study designs a self-rated questionnaire about cost-effectiveness analyses, including both direct and indirect costs, and the patients themselves fill out the questionnaire based on the bill. The cost-effectiveness analysis method (CEA) is used to measure the spending of three groups. The results of the total cost divided by YBOCS total reduction scores can reflect the cost required to obtain each unit of curative effect.

The cost-utility analysis method is used to measure the spending of improving patients' quality of life. The results of the total cost divided by SF-36 total improvement scores can reflect the cost required to obtain each unit of utility.

Frequency of occurrence is recorded to evaluate treatment acceptability. The investigators use sign-in sheets to measure patients' attendance during the treatment.

Homework completion is recorded to evaluate treatment acceptability. The investigators use sign-in sheets to keep track of patients' homework completion.

Subjective satisfaction with treatment is recorded to evaluate treatment acceptability. The investigators use a self-rated question（"Overall, how satisfied are you with your current treatment?") to measure patients' subjective satisfaction. The rating was done on a 7-item scale ranging from "Extremely dissatisfied" to "Extremely satisfied".

RDM is a classical perceptual decision paradigm, in which subjects need to report the overall movement direction of 300 randomly moving white dots, and the total duration of the task is about 25 minutes. RDM is often used together with drift diffusion models to study human decision-making processes and has been supported by many research evidences. After the RDM decision, a confidence assessment stage is added to measure the decision confidence of the subjects through their subjective reports.

The antisaccade task is a classical experimental paradigm to measure the response inhibition ability of subjects in the field of cognitive function.

The investigators use the randomized dot motion perceptual decision-making task as Neuroimaging Paradigm to observe the neurophysiological changes cauesd by step-ICBT in patients with OCD.

Inclusion Criteria: Age between 18 and 50 years Satisfied with the diagnostic criteria for OCD in DSM-V. 16≤YBOCS score ≤31 Taking medication stably for 8 weeks Education level ⩾6 years Has sufficient audiovisual skills to complete the necessary examinations for the study. Right-handed (this criterion is for fMRI subjects only) Subjects and their guardians understood the study and signed informed consent. Exclusion Criteria: Satisfied with the diagnostic criteria for a mental disorder in DSM-V other than OCD. Obsessive-compulsive symptoms were too severe to participate in the experiment. High risk of suicide. Severe central system or physical disease Pregnant women or women that getting ready for being pregnant and lactating. Other treatments being performed. Uncooperative or unable to complete treatment 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)