Cohort Study of Obsessive-Compulsive Disorder

This study will establish a standardized, multi-dimensional prospective longitudinal cohort for obsessive-compulsive disorder. It seeks to explore differences in symptom trajectories, functional trajectories, treatment responses, and long-term outcomes among different OCD clinical subgroups. Additionally, it will examine whether multi-modal measures (including clinical features, neuropsychological tests, neuroimaging, electroencephalography (EEG), magnetoencephalography (MEG), functional near-infrared spectroscopy (fNIRS), and blood and stool biospecimens) can explain clinical heterogeneity and predict treatment response and long-term prognosis.

Study Overview

• Status: Not yet recruiting
• Conditions: Obsessive - Compulsive Disorder

• Study Type: Observational
• Enrollment (Estimated): 500

Contacts and Locations

• Study Contact: Name: Qing Zhao; Phone Number: +86 18516539730; Email: zhaoqing@smhc.org.cn

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Participants will be recruited from clinical outpatient and inpatient units at Shanghai Mental Health Center. The study population consists of adult patients diagnosed with obsessive-compulsive disorder seeking routine clinical care. No investigator-assigned treatments are provided.

Description

Inclusion Criteria:

【First-episode obsessive-compulsive disorder subgroup】

• Aged 18-60 years, no restriction on sex;
• Meets DSM-5 diagnostic criteria for obsessive-compulsive disorder;
• Junior high-school education or above; able to understand study-related information and complete questionnaires and examinations;
• Has never received pharmacotherapy, psychological therapy or physical intervention for OCD;
• Voluntarily participates in this study and provides written informed consent. 【Initial-treatment non-responder subgroup】
• Aged 18-60 years, no restriction on sex;
• Meets DSM-5 diagnostic criteria for obsessive-compulsive disorder;
• Junior high-school education or above; able to understand study-related information and complete questionnaires and examinations;
• Has shown poor treatment response or intolerance after adequate-dose and adequate-duration treatment with one SSRI/SNRI agent, OR after receiving 12 sessions of cognitive-behavioral therapy (CBT);
• Voluntarily participates in this study and provides written informed consent. 【Pharmacotherapy-resistant subgroup】
• Aged 18-60 years, no restriction on sex;
• Meets DSM-5 diagnostic criteria for obsessive-compulsive disorder;
• Junior high-school education or above; able to understand study-related information and complete questionnaires and examinations;
• Demonstrates poor treatment response or intolerance following adequate-dose and adequate-duration treatment with two or more different SSRI/SNRI agents;
• Voluntarily participates in this study and provides written informed consent.

Exclusion Criteria:

• Meets the diagnosis criteria in DSM-5 except for obsessive-compulsive disorder (excluding obsessive-compulsive personality disorder);
• The obsessive symptoms are severe and prevent the patient from completing the required assessment tests;
• Pregnant or women who are about to become pregnant, lactating women;
• Have severe negative thoughts or a high risk of suicide;
• Have a history of other substance dependence or excessive use in the past year; 6) Other situations deemed unsuitable for inclusion by the researchers.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Obsessive-Compulsive Disorder Participants; This is a prospective, observational, longitudinal disease-specific cohort study for obsessive-compulsive disorder. This cohort contains first-episode obsessive-compulsive disorder, initial-treatment non-responders, and pharmacotherapy-resistant obsessive-compulsive disorder.No additional research-based randomization will be performed, and no therapeutic interventions will be assigned by investigators. After completing baseline assessments, participants with obsessive-compulsive disorder will enter longitudinal follow-up. After the first-year follow-up, participants will be followed-up every six-months for a total follow-up duration of 5 years. Collected data encompass clinical information and rating scales, biospecimens (blood, stool), neuropsychological tests, MRI, electroencephalography, functional near-infrared spectroscopy (fNIRS), eye-movement tests, and magnetoencephalography. Participants are permitted to enroll in optional nested sub-studies.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline in Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) total score	This scale was developed by Goodman et al. It is a widely used self-assessment tool for obsessive-compulsive symptoms both domestically and internationally, consisting of 10 items and 42 sub-items. The scale employs a 5-point rating system ranging from 0 to 4. The total score ranges from 0 to 40. The higher the score, the more severe the obsessive-compulsive symptoms. A total score of 8-15 indicates mild obsessive-compulsive symptoms, 16-25 indicates moderate symptoms, and a score above 25 indicates severe symptoms. Its Chinese version was introduced and validated for reliability and validity by our research group, and has been extensively adopted in both clinical practice and research settings. In the present study, Y-BOCS scores will be applied for participant screening at enrollment, and will also serve as an assessment tool for symptom severity during follow-up visits.	Baseline, 8-week, 12-week, 6-month, 9-month, 12-month, every 6-months thereafter up to total 5-year follow-up

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change from baseline in Beck Depression Inventory-Second Edition (BDI-II) total score	This scale was revised by Beck et al. and is a self-assessment tool used to evaluate the degree of depression. It consists of 21 items and is used to assess the severity of depressive symptoms. This scale uses a four-point rating system from 0 to 3. The total score ranges from 0 to 13 indicating no depression, 14 to 19 indicating mild depression, 20 to 28 indicating moderate depression, and 29 to 63 indicating severe depression.	Baseline, 8-week, 12-week, 6-month, 9-month, 12-month, every 6-months thereafter up to total 5-year follow-up
Change from baseline in Beck Anxiety Inventory (BAI) total score	This scale was developed by Beck et al. It consists of 21 items, each of which is rated on a scale of 0 to 3, representing four levels. It is a self-assessment tool for evaluating anxiety symptoms. The total score is the sum of all items, with a score range of 0 to 63. The higher the score, the more severe the anxiety. A total score of 15-25 indicates mild anxiety, 26-35 indicates moderate anxiety, and above 36 indicates severe anxiety. The Chinese version of this scale has good reliability and validity and is widely used in the assessment of anxiety symptoms.	Baseline, 8-week, 12-week, 6-month, 9-month, 12-month, every 6-months thereafter up to total 5-year follow-up
Number of participants experiencing any adverse event identified via participant follow-up interview	Adverse events prospectively captured during follow-up are documented, includes adverse events that may occur during the actual phamachotherapy treatment process of the research participants, as well as during psychological treatment or other intervention studies. During the research, the occurrence time, manifestation form, severity, handling measures, and outcome of the adverse events will be recorded.Each participant is counted once if one or more adverse events newly occur after study enrolment, regardless of total event episodes. Data will be summarized using participant counts and corresponding proportions.	From study baseline until the end of study follow-up (variable follow-up duration across participants)
Number of participants with suicidal-related events assessed by the Columbia-Suicide Severity Rating Scale (C-SSRS)	Suicidal-related events include suicidal ideation, non-suicidal self-harm and suicide attempts, identified using the C-SSRS structured interview. A participant will be counted only once if one or more suicidal-related events newly occur after study enrolment during follow-up, regardless of total event episodes. Data will be summarized as participant counts and corresponding proportions.	From study baseline until the end of study follow-up (variable follow-up duration across participants)
Number of participants experiencing serious adverse events identified via participant follow-up interview	Serious adverse events are defined according to ICH-GCP criteria. Events are documented using verbatim clinical descriptions obtained from study follow-up interviews. A participant will be counted only once if any serious adverse event occurs during follow-up, irrespective of the total number of individual events experienced. Only serious adverse events newly occurring after study enrolment are counted. Data will be summarized as participant counts and corresponding proportions.	From study baseline until the end of study follow-up (variable follow-up duration across participants)

Collaborators and Investigators

• Sponsor: Shanghai Mental Health Center
• Investigators: Principal Investigator: Qing Zhao, Shanghai Mental Health Center

Study record dates

Study Major Dates

• Study Start (Estimated): September 15, 2026
• Primary Completion (Estimated): December 31, 2030
• Study Completion (Estimated): December 31, 2030

Study Registration Dates

• First Submitted: September 8, 2026
• First Submitted That Met QC Criteria: September 10, 2026
• First Posted (Actual): September 16, 2026

Study Record Updates

• Last Update Posted (Actual): September 16, 2026
• Last Update Submitted That Met QC Criteria: September 10, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Keywords: Obsessive compulsive disorder; Longitudinal Study; Prospective Cohort Study; Clinical Subgroup
• Additional Relevant MeSH Terms: Mental Disorders; Personality Disorders; Anxiety Disorders; Compulsive Personality Disorder; Obsessive-Compulsive Disorder
• Other Study ID Numbers: 2025-SFDL06

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No