Can Brain Imaging Help Identify Universal Signatures of OCD?

What you need to know

• A large international study aims to identify brain signatures of obsessive-compulsive disorder (OCD) that are consistent across diverse populations worldwide.
• The study will use brain imaging, cognitive tests, and clinical assessments in 250 people with OCD, 100 of their unaffected siblings, and 250 healthy controls across five countries.
• Identifying universal brain signatures of OCD could lead to more objective diagnosis methods and new treatment targets with global relevance.

A Global Approach to Understanding OCD

Obsessive-compulsive disorder (OCD) affects 2-3% of people worldwide and can significantly impact quality of life. While treatments like cognitive-behavioral therapy and medications help some patients, many continue to struggle with symptoms. To improve care, researchers need a better understanding of how OCD affects the brain.

A new study aims to identify consistent brain signatures of OCD across diverse global populations. This international effort will examine brain structure and function in 250 people with OCD, 100 of their siblings without OCD, and 250 healthy controls across five countries - Brazil, India, the Netherlands, South Africa, and the United States.

“By joining forces globally, we can accelerate discovery of the brain basis of OCD in a way that’s relevant to patients worldwide,” says lead investigator Dr. Helen Blair Simpson of Columbia University.

Looking for Universal Brain Patterns

The study will use magnetic resonance imaging (MRI) to examine multiple aspects of brain structure and function:

1. Brain anatomy - High-resolution scans will measure the size and shape of different brain regions.

2. Structural connectivity - Special MRI techniques will map the white matter fibers connecting different parts of the brain.

3. Functional connectivity - Scans taken while participants rest quietly will reveal which brain regions tend to activate together.

Researchers will analyze these brain measures to identify patterns that reliably distinguish people with OCD from unaffected siblings and healthy controls across all five countries. They’ll also link the brain patterns to performance on cognitive tests and clinical features of OCD.

“If we can find brain signatures of OCD that are consistent across countries and cultures, it would be strong evidence that these are fundamental to the disorder,” explains Dr. Odile van den Heuvel of Amsterdam UMC, who is leading the brain imaging analyses.

Probing OCD-Related Brain Circuits

Prior research has found that OCD involves problems in communication between the frontal lobes and deeper brain structures. This study will examine several key brain circuits:

• Frontal-striatal circuits - Involved in habits, compulsions, and cognitive flexibility
• Frontal-limbic circuits - Important for processing emotions and threats
• Frontal-parietal circuits - Support attention and working memory

Participants will complete computerized tests targeting these circuits, like:

• Response inhibition tasks to assess impulse control
• Working memory tests
• Decision-making tasks involving rewards

“By examining both brain structure and function alongside cognitive abilities, we can better understand how brain circuit abnormalities may lead to OCD symptoms,” says Dr. Euripedes Miguel of the University of São Paulo.

The Sibling Connection

Including siblings without OCD provides a unique opportunity. Brain similarities between people with OCD and their unaffected siblings could reveal inherited risk factors. Differences may point to protective factors that prevent OCD in some family members.

“Unaffected siblings are a bridge between patients and controls,” explains Dr. Dan Stein of the University of Cape Town. “They can help us tease apart the effects of genetic risk, shared environment, and the illness itself.”

Cultural Considerations

While OCD has similar core features globally, its expression can vary across cultures. The study will explore how environmental and cultural factors may influence brain findings, including:

• Childhood trauma
• Socioeconomic status
• Religiosity

Participants will also complete the Cultural Formulation Interview to capture cultural perspectives on their symptoms.

“We want to understand both the universal brain basis of OCD and how culture and environment may shape its expression,” says Dr. Janardhan Reddy of the National Institute of Mental Health and Neurosciences in Bangalore.

Potential Impact

If successful, this study could change how OCD is understood, diagnosed and treated:

1. More precise diagnosis - Brain scans could one day complement clinical assessment to diagnose OCD more objectively.

2. New treatment targets - Identifying specific brain circuit problems may lead to more targeted therapies, whether medications or brain stimulation techniques.

3. Prediction and prevention - Understanding inherited brain risk factors could allow earlier intervention in vulnerable individuals.

4. Global relevance - Findings that hold up across countries are more likely to be useful worldwide, including in low-resource settings.

“Our goal is to advance a brain-based understanding of OCD that can improve care for patients globally,” says Dr. Simpson.

A Model for Global Mental Health Research

This study represents a new approach to mental health research that integrates neuroscience with global mental health. By harmonizing methods across diverse sites, it aims to produce discoveries relevant beyond just wealthy Western countries.

“Mental health research has often focused on a narrow slice of humanity,” explains Dr. Roberto Lewis-Fernández of Columbia University. “This study could be a model for identifying universal aspects of mental illness while still accounting for cultural variation.”

Conclusions

• This large international brain imaging study seeks to identify universal signatures of OCD across diverse global populations.
• Findings could lead to more objective diagnosis methods and new treatment targets for OCD with worldwide relevance.
• The collaborative approach integrates neuroscience and global mental health in a way that could be a model for future psychiatric research.

While results are still years away, this ambitious effort offers hope for new insights into OCD that could ultimately improve care for millions of people around the world. By bridging neuroscience and global mental health, it represents an innovative approach to unraveling the mysteries of the brain and mind.