Bulimia

Bulimia nervosa is a complex eating disorder characterized by episodes of eating large quantities of food (bingeing) and then engaging in purging or other methods to compensate for the binge eating. The term bulimia is derived from Greek to mean “ox hunger,” thus giving a concise description of one of the disor-der's key clinical features: excessive food consumption. [Page 319]Methods of purging typically include self-induced vomiting and abusing laxatives and/or diuretics. Fasting or excessive exercise are “nonpurging,” but they are, nonetheless, compensatory behaviors. Another significant feature of bulimia nervosa is a strong dissatisfaction with the individual's body weight and shape. Eating disorders such as bulimia nervosa and anorexia nervosa primarily affect women; an estimated 1 to 2 million women are afflicted with this disorder in the United States alone. If undiagnosed, bulimia nervosa can lead to serious medical consequences.

The Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV), published by the American Psychiatric Association, establishes criteria used by clinicians in diagnosing and distinguishing eating disorders. Unlike anorexia nervosa, there are explicit criteria for both frequency and duration for a diagnosis of bulimia nervosa. The DSM-IV criteria for bulimia nervosa include recurrent episodes of binge eating accompanied by a feeling of a loss of control (binge eating constitutes a consumption of larger-than-normal quantities of food in a discrete period); recurrent compensatory measures to avoid gaining weight post-binge that either involve purging (e.g., self-induced vomiting) or nonpurging activities (e.g., excessive exercise). The bingeing and purging behaviors occur a minimum of two times a week for a duration of three months; self-evaluation is disproportionately influenced by body shape and weight. In addition, these disturbances do not occur during episodes of anorexia nervosa.

Bulimia nervosa is a relatively “new” disorder; there are no data for bulimia nervosa prior to 1970. Like anorexia nervosa, bulimia nervosa is significantly more common in women than in men, affecting 1 to 3 percent of young females in their lifetime. Also, it is more common in developed countries such as the United States and has increased in prevalence over the last 50 years. Recent data from a nationally representative study of eating disorders in the United States report a lifetime prevalence of bulimia nervosa to be 1.5 percent in women and 0.5 percent in men. Peak onset, or beginning, of eating disorders typically occurs at either 14 or 18 years of age.

While research has yet to reach agreement as to the cause of eating disorders, cultural pressures such as an overidealization of thinness and a demonstrated prejudice against obesity have been implicated. As in anorexia nervosa, a number of factors have been observed to be associated with bulimic behavior: professions or artistic pursuits that involve a public display of the body (e.g., ballet, modeling); a history of dieting; biological deficiencies such as serotonin deficiency; and a history of physical or sexual abuse.

Similar to anorexia nervosa, bulimia nervosa is classified into two subtypes: purging subtype and non-purging subtype. The bulimia nervosa purging subtype involves the use of purging methods such as self-in-duced vomiting or laxatives to counteract the calories consumed during a binge episode. The nonpurging subtype attempts to achieve the same goal of avoiding weight gain by excessively exercising or fasting.

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