Responses to reading negative words in the amygdala and subgenual region of the anterior cingulate cortex predict which patients with depression will respond to cognitive behavioral therapy, according to an article in the April issue of The American Journal of Psychiatry.

The relationship was reported by Greg J. Siegle, PhD, assistant professor of psychiatry, University of Pittsburgh School of Medicine, in the article entitled “Use of fMRI to Predict Recovery from Unipolar Depression with Cognitive Behavior Therapy.”

The subgenual part of the anterior cingulate cortex is implicated in emotional regulation and the amygdala, which processes memories, is associated with emotional content. The subgenual cingulate cortex is thought to regulate the activity of the amygdala.

Before treatment, brain activity was measured with functional magnetic resonance imaging as depressed patients responded to words with negative, positive, or neutral associations. A total of 14 patients chose negative words that they felt described their feelings when they were depressed. Then the patients received 12 weeks of cognitive behavioral therapy.

Decreased activity in the subgenual cingulate cortex in response to negative words predicted which patients responded to cognitive behavioral therapy. Of the nine patients whose brain scans reflected this decrease before treatment, seven recovered during cognitive behavioral therapy compared with only one of five without the decrease.

Increased activity in the right amygdala during presentation of negative words was also associated with recovery but had less predictive power. Words with positive or neutral meanings did not produce changes related to recovery.

“The finding shows that cognitive behavior therapy, one of the psychotherapies offered to depressed patients, has a very specific action on the brain’s control of its emotional response,” said Robert Freedman, MD, journal editor-in-chief. “While we have always known that psychotherapy is generally helpful for depression, we have not known previously how targeted its effects are. Here we have a therapy that helps patients control their emotional response that is effective for those patients whose brain images show that they have difficulty with such control.”

The task of responding to emotionally negative words was chosen because previous imaging studies had shown that depressed people have greater reactivity in brain regions that process these emotions. Cognitive behavioral therapy specifically addresses patients’ ability to control their emotional reactions. It uses a short-term, structured format focusing on specific behaviors to interfere with automatic negative thoughts. The ability to identify before treatment those patients who can best benefit would increase the usefulness of cognitive behavior therapy. Conversely, identifying patients who are less likely to respond would provide the opportunity to direct these patients to other treatments.

The authors noted that the practical value of the finding will require more extensive testing.