Brain circuit abnormalities may underlie bulimia nervosa in women

Jan 05, 2009

Women with bulimia nervosa appear to respond more impulsively during psychological testing than those without eating disorders, and brain scans show differences in areas responsible for regulating behavior, according to a report in the January issue of Archives of General Psychiatry, one of the JAMA/Archives journals.

Bulimia nervosa often begins in the adolescent or young adult years, according to background information in the article. "Primarily affecting girls and women, it is characterized by recurrent episodes of binge eating followed by self-induced vomiting or another compensatory behavior to avoid weight gain," the authors write. "These episodes of binge eating are associated with a severe sense of loss of control."

Certain pathways between nerve cells known as frontostriatal circuits help individuals control their own voluntary behaviors, the authors note. These functions are tested during the performance of the Simon Spatial Incompatibility task, in which participants must indicate the direction an arrow is pointing regardless of where it appears on a screen. The task is easier when the arrow direction matches the side of the screen, but more difficult when, for instance, an arrow that points leftward appears on the right side of the screen. Ignoring the side of the screen to focus on the arrow direction requires regulating behavior by fighting the tendency to respond automatically and resolving conflicting messages.

Rachel Marsh, Ph.D., and colleagues at Columbia University and the New York State Psychiatric Institute, New York, compared the performance on the task of 20 women with bulimia nervosa with that of 20 healthy women who served as controls. Participants performed the task while undergoing functional magnetic resonance imaging (fMRI).

"Patients with bulimia nervosa exhibited greater impulsivity than did control participants, responding faster and making more errors on conflict trials [where the arrow direction and location did not match] that required self-regulatory control to respond correctly," the authors write. "They responded faster on congruent trials following incorrect conflict trials, suggesting impulsive responding even immediately after having committed an error." When patients with bulimia did respond correctly on trials in which the arrow side and direction did not match, their frontostriatal circuits did not activate to the same degree as did those of women in the control group.

"These group differences in performance and patterns of brain activity suggest that individuals with bulimia nervosa do not activate frontostriatal circuits appropriately, perhaps contributing to impulsive responses to conflict stimuli that normally require both frontostriatal activation and the exercise of self-regulatory control to generate a correct response," the authors conclude. "We speculate that this inability to engage frontostriatal systems also contributes to their inability to regulate binge-type eating and other impulsive behaviors."

To expand on this hypothesis, future studies should also include impulsive individuals who have healthy weights and eating behaviors, adolescents close to the time that bulimia nervosa develops and patients with varying severity of symptoms, they note.

Paper: Arch Gen Psychiatry. 2009;66[1]:51-63.

Source: JAMA and Archives Journals

Explore further: Missing protein restored in patients with muscular dystrophy

add to favorites email to friend print save as pdf

Related Stories

Orb-weaving spiders living in urban areas may be larger

35 minutes ago

A common orb-weaving spider may grow larger and have an increased ability to reproduce when living in urban areas, according to a study published August 20, 2014 in the open-access journal PLOS ONE by Eli ...

Swirling electrons in the whirlpool galaxy

1 hour ago

The whirlpool galaxy Messier 51 (M51) is seen from a distance of approximately 30 million light years. This galaxy appears almost face-on and displays a beautiful system of spiral arms.

Recommended for you

Student seeks to improve pneumonia vaccines

6 hours ago

Almost a million Americans fall ill with pneumonia each year. Nearly half of these cases require hospitalization, and 5-7 percent are fatal. Current vaccines provide protection against some strains of the ...

Seabed solution for cold sores

8 hours ago

The blue blood of abalone, a seabed delicacy could be used to combat common cold sores and related herpes virus following breakthrough research at the University of Sydney.

Better living through mitochondrial derived vesicles

Aug 19, 2014

(Medical Xpress)—As principal transformers of bacteria, organelles, synapses, and cells, vesicles might be said to be the stuff of life. One need look no further than the rapid rise to prominence of The ...

Zebrafish help to unravel Alzheimer's disease

Aug 19, 2014

New fundamental knowledge about the regulation of stem cells in the nerve tissue of zebrafish embryos results in surprising insights into neurodegenerative disease processes in the human brain. A new study by scientists at ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

gmurphy
not rated yet Jan 05, 2009
"their frontostriatal circuits", lol