Psychopharmacology of Eating Disorders

Anorexia nervosa (AN) and bulimia nervosa (BN) are disorders characterized by aberrant patterns of feeding behavior and weight regulation, and disturbances in attitudes toward weight and shape and the perception of body shape. In AN, there is an inexplicable fear of weight gain and unrelenting obsession with fatness even in the face of increasing cachexia. BN usually emerges after a period of dieting, which may or may not have been associated with weight loss. Either self-induced vomiting, or some other means of inappropriate compensation for the excess of food ingested follows binge eating. The majority of people with BN have irregular feeding patterns and satiety may be impaired. Although current AN is an exclusion for the diagnosis of BN, some 25% to 30% of individuals with BN presenting to treatment centers have a prior history of AN; however, all BN subjects have pathologic concern with weight and shape. Common to individuals with AN or BN are low selfesteem, depression, and anxiety. In certain respects, both diagnostic labels are misleading. Individuals affected with AN rarely have complete suppression of appetite, but rather exhibit a volitional and often an ego syntonic resistance to feeding drives, eventually becoming preoccupied with food and eating rituals to the point of obsession. Similarly, BN may not be associated with a primary pathologic drive to overeat; rather, individuals with BN, like those with AN, have a seemingly relentless drive to restrain their food intake, an extreme fear of weight gain, and often a distorted view of their actual body shape. Loss of control with overeating usually occurs intermittently and typically only some time after the onset of dieting behavior. Episodes of binge eating ultimately develop in a significant proportion of people with AN (1), whereas 5% of those with BN eventually develop AN (2). Considering that restrained eating behavior and dysfunctional cognitions