Brain scans may help predict response to OCD therapies

New research may help doctors predict which patients with OCD will benefit from cognitive behavioral therapy. FatCamera / E+ via Getty Images

Obsessive-compulsive disorder (OCD) is a common, chronic, and long-lasting mental health condition. People with OCD have uncontrollable, reoccurring thoughts (obsessions), behaviors (compulsions) that they feel the urge to repeat over and over, or both. Symptoms can interfere with all aspects of life, including work, school, and personal relationships.

A type of psychotherapy called cognitive behavioral therapy (CBT) has been shown to help many people with OCD cope with their recurrent and intrusive thoughts and behaviors. The approach most commonly used to treat OCD involves exposing people to their triggers and helping them reduce obsessive or compulsive responses.

Unfortunately, CBT doesn’t work for up to half of people with OCD. Researchers have not been able to predict beforehand who will benefit from this type of therapy. And why CBT helps some people but not others isn’t well understood. Some studies have suggested that measurements of brain activity before treatment may help scientists understand who will respond to CBT.

To look at the relationship between brain activity and CBT outcomes in both adolescents and adults, researchers led by Drs. Luke J. Norman (who is now at NIH), Kate Fitzgerald, and Stephan Taylor from the University of Michigan recruited 87 people, aged 12 to 45. All underwent a type of brain imaging called functional MRI (fMRI) at the start of the study. fMRI can measure what parts of the brain are active during different mental tasks.

Study participants played a computer game during fMRI that challenged various parts of the brain. Afterwards, they were randomly assigned to receive either CBT or another type of psychotherapy called stress management therapy (SMT) for 12 weeks.

The team measured participants’ OCD symptoms before, during, and after therapy. They examined whether brain activity patterns seen on the fMRI scans related to symptom improvement after therapy. The study was funded by NIH’s National Institute of Mental Health (NIMH). Results appeared on August 28, 2020, in the American Journal of Psychiatry.

People in both treatment groups experienced a reduction in their OCD symptoms after 12 weeks of therapy. Overall, those in the CBT group had a greater drop in symptoms over time. However, brain activity at the start of the study was linked to different outcomes.

People who had more activity in areas of the brain associated with controlling thoughts and evaluating rewards had better responses to CBT than those with less activity. Unexpectedly, those with less activity in these brain areas before therapy had a better response to SMT. These results were seen regardless of participants’ ages.

“Our research shows that different brains respond to different treatments, and if we can build on this knowledge we could move toward a more precision-medicine approach for OCD,” Fitzgerald says.

More work is needed to determine whether imaging or other tests of brain activity could be used in the clinic to tailor the type of treatment for OCD.

—by Sharon Reynolds