Reward Prediction Error in Anorexia
Anorexia Nervosa (AN) is a mental disorder of unknown cause. Understanding associations between behavior and the brain is important in treatment development. Using a new task (money as reward) during brain imaging (functional magnetic resonance imaging [fMRI]), DeGuzman and colleagues tested how brain reward learning in adolescent AN changes with weight restoration. Females with AN underwent fMRI before and after treatment, and females who were healthy underwent fMRI on two occasions. Brain function was tested using a model for rewards received and omitted (“reward prediction error construct”) related to internal motivation and brain levels (dopamine) of responsiveness. Compared to the healthy females, the AN females had greater brain response for prediction error, to unexpected reward receipt, and to unexpected reward omission. The responses for prediction error and unexpected reward omission tended to normalize with treatment, while unexpected reward receipt response remained higher after treatment. Greater prediction error response when underweight was associated with lower weight gain during treatment. In addition, punishment sensitivity was associated with prediction error response. The researchers concluded that reward system responsiveness is higher in adolescent AN when underweight and after weight restoration. Increased prediction error activity in brain reward regions may represent a type of adolescent AN that does not respond well to treatment. Prediction error response could be a brain marker of illness severity that can indicate individual treatment needs.
DeGuzman, M., Shott, M.E., Yang, T.T., Riederer, J., Frank, G.K.W. Association of elevated reward prediction error response with weight gain in adolescent anorexia nervosa. (2017). American Journal of Psychiatry, 174: 557 -565.
about the author: heather
Heather, MSW, LICSW, QCSW, ACSW has served on the Board of the National Eating Disorders Association (NEDA) since 2013, and collaborates with her NEDA colleagues on Eating Disorder research studies, papers, and presentations. Through her position at Brown University Department of Psychiatry and Human Behavior, she has also been collaborating with her local Rhode Island Hospital/Hasbro Children’s Hospital Eating Disorders Partial Hospital, Outpatient, and Home-Based clinical programs since 2013. Heather had Anorexia Nervosa for 23 years, and has been recovered since 2012.