Anorexia nervosa and bulimia

Eating disorders, including anorexia nervosa and bulimia nervosa, have long been recognized in psychiatry and other medical disciplines for their primary dysregulation in the basic ability to eat and inability to maintain weight without significant distress or dysregulation. Although the diagnostic criteria of these disorders have been debated over time, the core feature remain as (1) disturbances in the ability to maintain a healthy weight, (2) recurrent binge-eating or compensatory behavior, and (3) significant disturbances in the investment and perceptions of shape, weight, or appearance. The neurobiology of these disorders has been aided greatly by the study of eating behavior and weight regulation designed to study obesity. This chapter summarizes the current state of knowledge about the genetic, hormonal, neurotransmitter, and functional neurocircuitry of these disorders. Emerging evidence suggests that appetite hormones and peptides, adrenal hormones, ovarian hormones, and serotonin and dopamine are dysregulated in both disorders. Despite these advances, no neurobiological model has been able to explain the differences in prevalence rates between men and women or the common occurrence of expression during puberty. It is likely that relevant hormonal systems and neurotransmitter changes are working synergistically to affect these disorders. Future directions in translational and clinical research are discussed.