A Neuroimaging Examination of Binge Eating in Bulimia Nervosa and Binge Eating Disorder

Abstract

Eating disorders (EDs) are complex psychiatric illnesses involving genetic, environmental, cognitive and neurobiological factors. Recurrent, compulsive binge eating episodes (BEs) are a debilitating core symptom of bulimia nervosa (BN), binge eating disorder (BED), anorexia nervosa binge-purge subtype (AN-BP) and are a common feature of other specified feeding and eating disorder (OSFED). Neuroimaging techniques, particularly functional magnetic resonance imaging (fMRI), and research using fMRI in EDs, have both expanded significantly in recent decades. However, neuroimaging studies in BN and BED are significantly fewer relative to anorexia nervosa (AN). The use of disorder-relevant stimuli during neuroimaging, particularly food due to the role it plays in these illnesses, is a key area of interest, as understanding how the neural response to food differs in EDs can help to inform new, targeted treatment strategies. The aim of this thesis is to improve understanding of the differences in neural response between individuals with BN and BED compared to healthy controls (HCs) to low and high energy food stimuli. The thesis consists of a literature review and three peer-reviewed studies. The systematic review provides a comprehensive overview of the findings of 32 neuroimaging studies with BN and BED participants; the two empirical studies comprise a large fMRI study, with the first study examining neural responses of individuals with BN or BED to low energy foods compared to neutral items; the second empirical study with the same cohort investigated the profile of neural responses towards high energy food images. It is hoped that the findings of the studies increase understanding of the neural differences that may underlie compulsive binge eating in those with BN and BED and inform improvements in evidence-based treatment options.