A new study suggests that brain imaging can identify patients whose depression would more likely be relieved by a type of talk therapy.

Depressed patients whose MRI scans indicated certain brain responses to negative stimuli were more often helped by cognitive behavior therapy, according to the study, published in the April issue of the American Journal of Psychiatry.

If the findings are confirmed by other studies, "we may be able to predict what therapies will be most effective for individual patients by using imaging technology, bypassing the lengthy trial and error process that is often necessary to find the right treatment," said Dr. Greg Siegle, the study's principal researcher and an assistant professor of psychiatry at the University of Pittsburgh School of Medicine.

More than 17 million U.S. adults will experience at least one episode of major depression this year. Of those who seek treatment, just 40 to 60 percent will respond to initial therapy.

Cognitive behavior therapy, also known as cognitive therapy or CBT, is a type of psychotherapy used to treat patients with depression, anxiety or other problems. It involves helping patients recognize negative patterns of thinking and reacting, then replace them with more productive alternatives.

The findings show that CBT "has a very specific action on the brain's control of its emotional response," said Dr. Robert Freedman, a psychiatrist and editor-in-chief of the Journal of Psychiatry. "While we have always known that psychotherapy is generally helpful for depression, we have not known previously how targeted its effects are."

The study involved 14 people with depression who were not being treated with medication and 21 people in a control group who had never reported depressive symptoms.

While receiving an MRI scan, study participants were directed to read certain words -- including some, such as "guilt," that could have negative connotations -- and were asked if the words applied to them. They also volunteered words they considered positive, negative or neutral.

The 14 participants with depression then completed 16 sessions of CBT. At each session, they were assessed to determine the severity of their depression.

Of the nine patients who recovered from depression during CBT, seven had MRI scans that showed decreased activity, when negative words were considered, in the subgenual cingulate cortex, an area of the brain believed to be involved in regulating emotions. Among the five patients who did not recover, four had higher activity in that area.

The finding suggests that patients with lower levels of activity "were not regulating their emotions as much," Dr. Siegle said, so a therapy such as CBT that "teaches them to regulate emotions may be very effective."

Increased activity in the right amygdala, an almond-shaped structure located on the left and right sides of the brain, also was associated with improvement with CBT.

The amygdala is linked to automatically recognizing emotional aspects of information and generating emotional reactions, Dr. Siegle said. Since CBT may help patients to achieve better control, he said the therapy may be most appropriate for depressed people who have such exaggerated responses before therapy.

Other co-authors included Drs. Cameron Carter, a professor of psychiatry at the University of California, Davis, and Michael Thase, professor of psychiatry at the Pitt.

The Pittsburgh researchers have recently received funding to conduct a similar study in 70 people, Dr. Siegle said. They also hope to evaluate participants who complete CBT to determine whether changes occur in their brains.

More info

More information on the ongoing study is available by contacting the Mood Disorders Treatment and Research Program at 1-888-427-1532.