Bulimia Nervosa and Alcohol Use Disorder: Evidence for Shared Etiology and Neurobiology

Bulimia nervosa (BN) is a serious eating disorder characterized by recurrent binge eating episodes and dysfunctional compensatory behaviours, with a prevalence rate of up to 3%. Epidemiological studies show that BN and alcohol use disorder (AUD) co-occur very frequently in both clinical and community settings. Considering that eating disorders with comorbid AUD are associated with serious medical complications, poor treatment outcome and the highest lifetime mortality among all psychiatric disorders, there is great need for developing a better understanding of the nature of this comorbid relationship. This review is designed to critically evaluate the literature on BN and AUD and discuss the similarities between these two psychiatric disorders to offer a comprehensive summary of this serious psychiatric comorbidity. We will first analyze the complex and multi-dimensional etiology of these disorders as well as report on shared developmental pathways. We will then review the role of shared neurobiology, focusing on a variety of neurotransmitters including dopamine and serotonin. We will also comment on the role of shared genetic vulnerabilities in the development of BN and AUD. The section on treatment will cover pharmacological and psychological treatments for BN and AUD. Finally, we will discuss the challenges related to gaining a better understanding of comorbid BN and AUD, as well as propose future directions for research.