Anorexia and bulimia nervosa

Anorexia nervosa (AN) and bulimia nervosa (BN) are disorders characterized by abnormal patterns of weight regulation and eating behavior and by distur bances in attitudes and perceptions toward weight and body shape. Etiologic research has indicated substantial genetic influence on these disorders, s uggesting significant biological contributions to their development. Obsess ional, perfectionistic, and anxious personality styles may be premorbid tra its that contribute to this pathogenesis. Studies of neuroendocrine, neurop eptide, and neurotransmitter functioning in patients with AN and BN indicat e that disturbances of these systems may contribute to the maintenance as w ell as the etiology of these sometimes fatal disorders. The efficacy of psy chological treatments and pharmacotherapy has been more clearly established for BN than for AN.