Brain Imaging Predicts Effectiveness of
Cognitive Behavior Therapy for Depression
Whether or not cognitive behavior therapy (CBT) will
help a person recover from depression can be predicted through brain imaging,
according to research results published by the University of Pittsburgh School
of Medicine in the April issue of the American Journal of Psychiatry, the
official journal of the American Psychiatric Association.
More than 17 million adults in the United States
will experience at least one episode of major depression this year; of those who
seek treatment, only 40 to 60 percent will respond to any given first-line
treatment, whether it be therapy or medication. However, researchers have found
that most eventually will respond once they find the right treatment. Being able
to predict who will respond to CBT, and who will not, may prove to be a valuable
tool for treating depression.
"For depression, there is no single medication or
therapy that has been found to work as a primary treatment for most patients,"
said Greg J. Siegle, Ph.D., assistant professor of psychiatry, University of
Pittsburgh School of Medicine. "We found that people with depression who have
increased activity in one area of the brain and decreased activity in another in
response to emotional stimuli are more likely to respond to a specific
treatment--cognitive therapy. If this finding holds true, 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."
The study used functional magnetic resonance
imaging (fMRI) to identify which areas of the brain were active or inactive when
exposed to a negative stimulus. While undergoing fMRI, 14 unmedicated
participants with depression and 21 control subjects who had never reported
symptoms of depression were presented with emotional words and asked if those
words applied to them. The participants with depression then completed 16
sessions of CBT over 12 weeks as part of a larger clinical trial.
Researchers found that compared to controls, nine
of the participants with depression had decreased activity in a region of the
brain called the subgenual cingulate cortex after they read negative words. Of
those nine, seven recovered from their depressive symptoms after CBT. Only one
of the five participants with depression who did not demonstrate decreased
activity in the subgenual cingulate cortex recovered after CBT. Better recovery
also was associated with increased activity after reading negative words in a
brain region called the amygdala.
"The amygdala helps us to recognize things as
being emotional. In some people with depression, the amygdala doesn't turn off
as fast as it should after it recognizes something as being negative. The
subgenual cingulate cortex regulates emotions and plays a part in turning the
amygdala on and off," said Dr. Siegle. "If the amygdala doesn't get 'turned off'
in a person with depression, when exposed to negative information, the person
may ruminate, going over this information again and again. Cognitive behavioral
therapy teaches people techniques to stop this rumination, so it makes sense
that it would be a good treatment option for those people who can't turn off
their amygdala," said Dr. Siegle.
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The Pittsburgh researchers have recently received
funding from the National Institute of Mental Health (NIMH) to replicate this
study in a larger group of people. Additionally, they hope to evaluate the
participants after they complete a course of CBT to determine what changes occur
in their brains.
This study was funded by NIMH, the National
Alliance for Schizophrenia and Depression (NARSAD), and the Veteran's Research
Foundation.
In addition to Dr. Siegle, co-authors of the
paper are Michael E. Thase, M.D., professor of psychiatry, University of
Pittsburgh School of Medicine; and Cameron S. Carter, M.D., professor of
psychiatry, University of California, Davis, formerly with the University of
Pittsburgh.
