Brains of Bulimia Patients Wired Differently

The researchers compared results from fMRI on 20 women (average age about 26) with bulimia nervosa and 20 age-matched controls.

Participants were shown pictures with arrows pointing either left or right and were asked to identify which way the arrows were pointing. In the simple version of the task, the arrows pointing left were on the left side of the screen and the right-directed arrows on the right side of the screen.

For the more difficult component of the task, the leftward-pointing arrow was positioned on the right side of the screen.

"When individuals are performing correctly, they need to engage self-regulatory control or cognitive control. They need to hold back the automatic response strategy in order to perform correctly," Marsh explained.

Women with bulimia nervosa performed faster on the difficult trials and made more errors and, when they were performing the task, they did not engage the same brain circuitry as the controls.

Participants with the most previous bulimic episodes and the highest rates of preoccupation with shape and weight performed the worst on tasks and engaged the frontostriatal circuits the most.

Healthy controls activated the anterior cingulated cortex region of the brain more when making correct responses and the striatum more when delivering incorrect responses.

More information

The U.S. National Institute of Mental Health has more on eating disorders.

SOURCES: Rachel Marsh, Ph.D., assistant professor, clinical psychology, division of child and adolescent psychiatry, Columbia University, New York City; Daniel le Grange, Ph.D., professor, psychiatry and behavioral neuroscience, and director, Eating Disorders Program, University of Chicago; Mary Tantillo, Ph.D., R.N., associate professor, clinical nursing, University of Rochester School of Nursing, and director, Western New York Comprehensive Care Center for Eating Disorders; January 2009, Archives of General Psychiatry