Bulimia Nervosa

Bulimia nervosa is an eating disorder characterized by binge eating with the maintenance of body weight.

Epidemiology

The estimated point prevalence of bulimia nervosa is 1 % to 3% of women. The male-female ratio is 1 : 10. This illness occurs disproportionately among whites in the United States.

Etiology

Many of the factors in the genesis of anorexia nervosa are also implicated in bulimia nervosa. Familial and genetic studies support similar familial linkages in both disorders. Psychological theories for bulimia nervosa stress an addiction or obsessive-compulsive behavioral model. Biologic, neurologic, and endocrine findings are less prominent in theories of causation of bulimia nervosa. Abnormal serotonin metabolism is thought to play more of a role in bulimia nervosa than in anorexia nervosa.

Clinical Manifestations

History and Mental Status Examination
Bulimia nervosa is diagnosed in individuals who engage in binge eating and behaviors designed to avoid weight gain but who maintain their body weight. In addition, these are people whose self- evaluation is overly influenced by their body weight and shape.

Food binges in bulimia nervosa may be precipitated by stress or altered mood states. Once a binge begins, the individual typically feels out of control and continues to eat large quantities of food, often to the point of physical discomfort. Purging may follow and most often consists of vomiting, usually induced mechanically by stimulating the gag reflex or using ipecac. Other purging methods used to avoid weight gain include laxative and diuretic abuse and enemas. Bulimic individuals often exercise and restrict their food intake. As in anorexia nervosa, patients with bulimia nervosa are overly concerned with body image and are preoccupied with becoming fat. Bulimia nervosa is classified into two subtypes: nonpurging type or purging type (see Table 6-1) according to whether purging behavior is present.

Differential Diagnosis

Bulimia nervosa should be distinguished from the binge eating and purging subtype of anorexia nervosa. If body weight is less than 85% of ideal, a diagnosis of anorexia nervosa is made. Binge eating can occur in major depression and in borderline personality disorder, but is not tied to a compulsion to reduce weight.

Management

The treatment for bulimia nervosa is similar to that for anorexia nervosa. Although medical complications of starvation are not present, other medical complications can require careful medical management and, at times, hospitalization. Psychotherapy focuses at first on achieving control of eating behavior. Cognitive therapy may be useful in treating overconcern with body image. Self-esteem and interpersonal relationships become the focus of therapy as the behavioral problems abate. Antidepressants, especially SSRls, are more effective in the treatment of bulimia nervosa than in anorexia nervosa (including those patients who do not have comorbid depression).