Women suffering from the eating disorder known as bulimia nervosa may be more impulsive because of their brain activity patterns, a new study shows. These women have impaired activity within a brain framework that governs self-regulatory processes, according to Rachel Marsh, Ph.D., of Columbia University and the New York State Psychiatric Institute, and colleagues.

 

The study included 20 women with bulimia and 20 women without the disorder. They had the same age and BMI. The participants had their brain scanned using functional magnetic resonance imaging (fMRI) while they took a brain function test. They were asked to signal the direction of an arrow using different fingers on a response box. Each round consisted of 102 stimuli and the experiment was repeated 10 times.

 

The bulimic women tended to respond faster to incongruent stimuli and to respond wrong at the test due to the fact that they were more impulsive and inaccurate when the arrow's direction didn't match its screen location. Those with the most severe bulimia symptoms had the lowest scores at the test.

The researchers suggest a possible explanation: problems with the brain chemicals serotonin and dopamine. The results of the study imply that “self-regulatory processes are impaired in women with [bulimia], likely because of their failure to engage frontostriatal circuits appropriately,” the researchers explained. Another possible explanation might be a chronic illness. The findings can’t be applied to men or adolescents with the disorder, as the study included only adult women.

 

The study was published in January’s edition of the Archives of General Psychiatry.