Doctors may be able to predict how people with obsessive-compulsive disorder will respond to therapy using a simple brain scan, according to the findings of a new study.

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Obsessive-compulsive disorder often causes people to perform certain rituals and behaviors repetitively to relieve anxiety.

The study, published in Frontiers in Psychiatry, is the first to use brain connectivity to predict the progression of a condition after treatment, as well as being the first to assess the impact of cognitive behavioral therapy (CBT) on brain network connectivity.

"The efficiency of brain network connectivity before treatment predicts the worsening of symptoms after treatment," states study author Jamie Feusner, an associate professor psychiatry at the University of California, Los Angeles (UCLA).

Between 1-2% of the American population is estimated to have obsessive-compulsive disorder (OCD). The disorder is characterized by frequent upsetting thoughts that patients will try to control through the repetition of certain rituals and behaviors.

Not only can OCD be a profoundly distressing condition but it can also severely disrupt the everyday routines of those who experience it, adversely affecting the ability to learn, work or maintain relationships.

CBT is frequently used as a form of treatment for OCD, teaching patients different ways of reacting to situations that cause distress without having obsessive thoughts or acting compulsively.

Unfortunately, CBT is not effective for every patient. In fact, the authors of the study state that in an estimated 20% of patients, the symptoms of OCD eventually return after a course of CBT has finished.

Understanding what factors help predict who will relapse after CBT has long been a goal for psychiatry researchers. The new study, conducted by researchers at UCLA and colleagues, indicates that functional magnetic resonance imaging (fMRI) could help.

For the study, the researchers examined the brains of 17 participants with OCD aged 21-50. Each participant received a 4-week course of CBT, and fMRI scans were taken of their brains both before and after the therapy. Over the following 12 months, doctors monitored their clinical symptoms.

"We found that cognitive behavioral therapy itself results in more densely connected local brain networks, which likely reflects more efficient brain activity," says Feusner.

Scans showing functional network efficiency found to predict OCD relapse

The participants whose scans revealed more efficient brain connectivity before CBT fared worse during the follow-up period than those whose connectivity was less efficient before receiving therapy.

In contrast, the severity of symptoms prior to CBT and how well the symptoms improved following CBT did not predict how well the participants would fare during the follow-up period.

This clue to how patients will respond to CBT in the long term could prove to be beneficial to both doctors and patients in the future if the results can be confirmed in larger studies.

"Cognitive-behavioral therapy is in many cases very effective, at least in the short term. But it is costly, time-consuming, difficult for patients and, in many areas, not available," Feusner explains. "Thus, if someone will end up having their symptoms return, it would be useful to know before they get treatment."

For those who might find a 4-week course of CBT ineffective, Feusner is keen to point out that alternative forms of treatment exist. Anti-anxiety medications and antidepressants are commonly prescribed by doctors, and longer courses of CBT could be beneficial.

The researchers now aim to validate their findings by conducting a study with a larger number of patients. While doing so, they will also look at other measures of brain function and structure in the hope of identifying further predictors of the clinical course of OCD post-treatment.

"We are now starting to translate knowledge of the brain into useful information that in the future could be used by doctors and patients to make clinical decisions," Feusner concludes.

"Although a brain scan may seem expensive, these scans only took about 15 minutes and thus the cost is not exceptionally high, particularly in comparison to medication or cognitive-behavioral therapy treatments, which over time can cost many thousands of dollars."

Previously, Medical News Today reported on a study that found CBT used to reduce chronic tics in people with Tourette syndrome can also alter the functioning in specific areas of the patients' brains.