The Neurobiology of Anorexia Nervosa and Abnormal Reward Learning Processes: A Systematic Review

Abstract Objective: Given the array of neuroimaging studies examining the neurobiology of anorexia nervosa, the purpose of this paper was to further highlight localized neurobiological abnormalities when examining reward learning pathways in patients suffering from AN. Methods: Literature searches using PsycINFO, EMBASE, and MEDLINE were conducted in March of 2022 using search terms relating to AN, reward learning, and neuroimaging. Relevant studies that were included must be written in English, have at least one clinical sample of either acute and/or recovered adult and/or adolescent female patients with anorexia nervosa, be controlled studies with a healthy female control group, be published in a peer-reviewed journal, and containing a neuroimaging component. Results: For this systematic review, 20 relevant studies were included to elucidate the brain regional and functional differences with respect to reward learning pathways in individuals with AN when compared to healthy controls. These differences include dopamine neuron and cortisol release abnormalities in relation to dopaminergic pathways, as well as regional differences involved in reward learning subconstructs that include reward expectancies, punishment sensitivity, social reward, and body dissatisfaction and body image distortion. Conclusion: In examining the brain regional and functional differences across individuals with AN with respect to the reward learning construct, further research efforts that focus on these important reward learning abnormalities might help inform the development of new clinical interventions aimed at these particular pathways.