Researchers at the UCSD School of Medicine recently published a study examining the brain functions of those suffering from anorexia nervosa in the April 1 issue of Biological Psychiatry. This study could help develop future treatment options, including those offered by the Eating Disorders Center for Treatment and Research Program at UCSD.
The purpose of the study was to understand the brain mechanisms by which individuals with anorexia can continue to restrict food, even when starving. In order to examine this, the team compared reward processing in the brains of 23 women who had recovered from anorexia to the brains of 17 healthy women.
Director of the Eating Disorders Treatment and Research Program at UCSD and Senior Author Walter Kaye explained to the UCSD Guardian how the study demonstrates the differences in the brain mechanisms of these two groups of women.
“This study shows that hunger increases activity in the part of the brain that motivates the seeking of rewarding stimuli in healthy subjects,” Kaye said. “However, in people who have been remitted from anorexia nervosa, hunger does not active these reward-related areas.”
One of the study’s methods was to use brain imagery to analyze both sets of women’s brains after they had fasted for 16 hours and after they had eaten a standard meal.
Researchers observed that the reward system, a group of neural structures involved with mediating reinforcement, was very active in the brains of the healthy women after they had finished a meal. In comparison, the reward system of the women who had suffered from anorexia was not as active.
These results demonstrated that in women who suffered from anorexia, this area of the brain did not distinguish between hunger and satiety to make food more appealing. Thus, hunger did not serve as motivation to engage in reward-seeking behavior, such as eating.
Another discovery revealed that parts of the brain within the frontal lobe responsible for self-control were overactive in women who had suffered from anorexia regardless of metabolic state. This finding suggests an imbalance between reward sensitivity and self-control that may partly explain why individuals suffering from anorexia are not tempted to eat even what researchers deemed more satisfying foods.
Associate Professor and First Author Christina Wierenga believes that the study could have significant implications for the way that anorexia is viewed.
“The study provides further evidence that this is a neurobiology-based, or brain-based, disorder,” Wierenga told the Guardian. “We hope that this will serve to reduce the stigma surrounding it.”
Wierenga also hopes that the conclusions of the study will provide a target for intervention and a guide for treatment, as it already has at the Eating Disorders Treatment and Research Program.
UCSD Counseling and Psychological Services psychologist and former Project Manager at Eating Disorders Treatment and Research Program Elise Curry told the Guardian how significant reducing the stigma of eating disorders is, especially for college students.
“If the stigma against eating disorders was reduced by viewing them as biological illnesses, maybe more of our students who struggle would seek the treatment that they need,” Curry said. “Students are often ashamed of having an eating disorder and may hide it from their friends and roommates. This can be tragic since early intervention has been shown to increase the chances of a full recovery.”
The results will later be used to guide studies at UCSD on how these brain mechanisms affect those suffering from bulimia nervosa, as well as studies examining what other factors may contribute to anorexia.
According to Wierenga, more research continues to be necessary to further treatment and understanding of the disorder.
“Right now there are no FDA-approved medications for anorexia, and existing psychological therapy is not always effective,” Wierenga said. “The only way to develop better treatments is to better understand the cause of the disorder.”
