Although considerable progress has been made in the understanding and treatment of anorexia and bulimia nervosa, a substantial proportion of people with these disorders have a limited response to treatment. Treatment strategies used in eating disorders have tended to be adopted from therapies that were devised to treat other psychiatric illnesses. Recent studies suggest that eating disorders are independently transmitted familial liabilities with a unique pathophysiology. These new findings raise the possibility that an improved understanding of the pathogenesis of eating disorders will generate more specific and effective psychotherapies and pharmacologic interventions.