About the Study

About the Study


We are now recruiting specifically for the treatment component of this study, click here for more information.

This international multisite study investigates how the brains of people with obsessive-compulsive disorder (OCD) work.

There is a need for a large well-powered multimodal imaging study in well-characterized unmedicated OCD patients that transcend countries and cultures. In addition, the need to identify robust biosignatures of core OCD features across countries and cultures has also been expressed. These signatures may then be used to chart how the disease develops and to develop tailored treatments for populations across the globe.

The short-term goal of this study is to identify brain signatures associated with cognitive and clinical profiles common in individuals with OCD that are reproducible across countries and cultures of OCD, leveraging global collaboration both to recruit a very large unmedicated sample and to prove these signatures’ reproducibility.

The long-term goal is to identify brain signatures for measurable behaviors and clinical symptoms that cut across traditional diagnostic categories and to use these signatures to transform how we conceptualize, diagnose and ultimately treat mental illnesses like OCD. This multinational project allows the researchers to gather a wealth of data on the brain functioning and structure of people with OCD, rendering a significant contribution to existing knowledge about the brain of people with OCD from different cultures and nationalities.

Study Information

The project was launched early in 2018, and will be conducted over a period of approximately 5 years. The researchers acquire morphometry (using T1-weighted MRI), Diffusion Tensor Imaging (DTI), and resting-state fMRI (rs-fMRI) scans, as well as interview, self-report and behavioral data from 250 unmedicated adults (18-50 years, 50 per site) with OCD and 250 matched healthy control participants (50 per site), over 5 years.

The 5 study sites and their respective principal investigators are:

  1. U.S.A.: Columbia Psychiatry (Dr Blair Simpson)
  2. Brazil:  Department & Institute of Psychiatry, University of Sao Paulo, School of Medicine (Dr Roseli Gedanke Shavitt)
  3. Netherlands: VU University Medical Center (VUmc)/Amsterdam (Dr Odile van den Heuvel)
  4. South Africa: MRC Unit on Risk and Resilience in Mental Disorders (SU and UCT) (Prof C. Lochner (University of Stellenbosch); Prof Dan J. Stein (UCT)
  5. India: National Institute of Mental Health & Neurosciences (NIMHANS), Bangalore (Dr Janardhan Reddy)

Study Procedures:

  1. Screening and Intake: After providing written consent, subjects undergo a psychiatric and diagnostic evaluation by a trained clinician, and a physical review of history (including BMI and history of Tic Disorders).
  2. Assessments: Participants are interviewed using scales to assess OCD, depression, anxiety symptoms, symptom severity and improvement, quality of life, and functional impairment. Participants also complete a number of self-report questionnaires to assess IQ, response inhibition (cognitive control), and reward processing mechanisms.
  3. MRI scans: Neuroimaging consist of 60 minutes of 3D T1 Weighted structural 1 mm scan, rs fMRI and DTI.

Data Analysis

The idea is to examine multiple brain circuits thought to underlie OCD behaviors, focusing on morphometry (using T1-weighted MRI), structural connectivity (using DTI), and functional connectivity (using rs-fMRI). The aim is to identify neuroimaging signatures that distinguish individuals with OCD from HCs by analyzing each modality with standardized protocols and by using multi-modal fusion with modern machine learning statistical methods. The researchers will then examine how these imaging signatures are linked to behavioral performance on cognitive tasks that probe these same circuits and to a range of clinical profiles that are common to OCD. Finally, the way in which specific environmental features (i.e. childhood trauma, socioeconomic status, and religiosity) may moderate this brain-behavior relationship, will be examined.

Taking Part

Individuals with OCD, and siblings of individuals with OCD, and healthy controls, between the ages of 18 and 50 years, who are physically healthy, and not taking psychotropic medications, are invited to take part.

If you are interested, your participation will include a comprehensive diagnostic interview, completion of questionnaires and a neuropsychological assessment and brain imaging (MRI). Participation is voluntary and confidential, and you can withdraw at any time.

If you are interested in taking part in the treatment component of this study,
please select your country: