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Eating Disorders Change Reward Processing in Brain, Reinforcing Disordered Behaviors
Eating disorder behaviors appear to change reward processing and food intake control circuitry in the brain, subsequently reinforcing the eating disorder behaviors, suggests a study published online in JAMA Psychiatry.
“This work is significant because it links biological and behavioral factors that interact to adversely impact eating behaviors,” said Janani Prabhakar, PhD, of the division of translational research at the National Institute of Mental Health. “It deepens our knowledge about the underlying biological causes of behavioral symptom presentation related to eating disorders and will give researchers and clinicians better information about how, when, and with whom to intervene.”
The study, supported by the National Institutes of Health, investigated how behaviors across a spectrum of eating disorders affect the brain’s response to rewards, and how such changes may also affect food intake control circuitry and reinforce the behaviors. Some 197 young women with anorexia nervosa, bulimia nervosa, binge-eating disorder, and other specified feeding and eating disorders with varying body mass indexes (BMIs) were included, as well as 120 women without eating disorders who served as healthy controls.
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Participants underwent cross-sectional functional brain imaging while they received, or were denied, an unexpected taste of a sugar solution. Researchers gauged each participant’s prediction error response to the reward—a dopamine-related signaling process that reflects how surprised a participant was to receive the unexpected stimulus.
In women with eating disorders, higher BMI and binge-eating behaviors were associated with a lower prediction error response, indicating less surprise to the stimulus, according to the study. Women with anorexia nervosa and lower BMI had a higher prediction error response, reflecting more surprise to the stimulus. Meanwhile, researchers found no significant correlations between BMI, eating disorder behavior, and brain reward response in the healthy control group.
In women with eating disorders, ventral striatal-hypothalamic circuitry was positively related to prediction error response and negatively correlated with feeling out of control after eating, researchers reported.
Such results suggest that eating disorder behaviors and excessive weight loss or gain effectively adjust the dopamine-related reward circuit response in the brain, researchers explained. Altered brain circuitry is linked with food intake control and, consequently, reinforcement of disordered eating behaviors.
“The study provides a model for how behavioral traits promote eating problems and changes in BMI, and how eating disorder behaviors, anxiety, mood, and brain neurobiology interact to reinforce the vicious cycle of eating disorders, making recovery very difficult,” said first author Guido Frank, MD, of the University of California San Diego.
—Jolynn Tumolo
References
Eating disorder behaviors alter reward response in the brain. News release. National Institute of Mental Health; June 30, 2021. Accessed July 2, 2021.
