Bulimic brains suffer neural abnormalities

New York, United States, January 7: Women with bulimia nervosa, an eating disorder characterized by alternating binge eating and purging episodes, have brains that suffer self-regulatory neural abnormalities, an activity pattern that triggers impulsivity, a new study shows.

The study carried out by a team of experts from Columbia University in collaboration with the researchers from New York State Psychiatric Institute zeroed in on 40 women (20 with bulimia and 20 without bulimia), all in mid-20s. All women had a comparable BMI (Body Mass Indexdefine, a method of measurement defined as the individual's body weight divided by the square of their height).

Each woman was put through a brain function test. Simultaneously, their brain activity was scanned using the functional magnetic resonance imaging (fMRI) technology.

The participants were judged on the accuracy and speed with which they identified the direction of the arrows popping up on the computer screen. While identifying the arrow’s direction (either left or right) was simpler when a left pointing arrow popped on the left side of the screen and a right pointing arrow appeared on the right side of the screen, the matters complicated when the arrow's direction did not match its screen location.

As expected, women with most severe bulimia nervosa scored the least in the test. A closer look revealed that bulimic brains reported least activity in brain areas that were involved in self-regulation, as compared to brains of women without bulimia.

"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" study’s lead author, Rachel Marsh, an Assistant Professor of clinical psychology in the division of child and adolescent psychiatry at Columbia University in New York City, explained.

While the exact reason behind the plunged brain activity is not known, researchers believe brain chemicals serotonin and dopamine, the key neurotransmitters, may be involved.

Bulimia nervosa typically afflicts adolescent girls. However, adolescent boys too are now coming in the grip. As the afflicted fail to restrain themselves from binge-eating, weight gain and body shape issues provoke purging through self-induced vomiting, fasting, use of laxatives, enemas, diuretics, or excessive exercising. The condition can be potentially life-threatening.

The study features in the January issue of the Archives of General Psychiatry.