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Article Excerpt
Eating disorders are serious emotional and physical illnesses that can have dangerous, even fatal, consequences. These disturbances in eating behavior range from severe restriction of food intake and emaciation, as in anorexia nervosa, to compulsive overeating or bingeing and purging, as in bulimia nervosa. Anorexia and bulimia, the predominant eating disorders, mainly affect females between ages 14 and 40, but men and women of any age, social class, or ethnicity may be affected. Primary care providers, who are often first to see patients with eating disorders, must be familiar with the clues for early diagnosis to ensure appropriate referral and timely intervention.
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Each year, about five million Americans are affected by an eating disorder. (1) The most common disorders, as described in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR), (2) are anorexia nervosa (AN) and bulimia nervosa (BN). The DSM-IV-TR also describes eating disorder not otherwise specified (ED-NOS). By recognizing patients at risk and intervening early, primary care providers can prevent the development of full-blown eating disorders; they must also be able to identify patients with established eating disorders. (3,4)
According to the DSM-IV-TR, the AN patient exhibits a willful refusal to make expected weight gain (if still growing) or to maintain a minimally normal weight (ie, falling at least 15% below ideal body weight), an intense fear of weight gain, and a significant misinterpretation of body shape. (2) Patients may have a body mass index below 17.5 kg/[m.sup.2], and those who have passed menarche may become amenorrheic. In AN, the overall mortality rate is 5% per decade (1)--the highest of any psychiatric illness. Death is usually attributed to a medical complication (eg, cardiac arrest, electrolyte imbalance) or suicide. (1,5)
AN may be divided into two subtypes, the restricting type (characterized by dieting, fasting, and/or excessive exercise) and the binge-eating/ purging type. (2,6,7)
The DSM-IV-TR defines BN as binge eating (uncontrolled consumption of large amounts of food in a limited period of time) combined with inappropriate ways to prevent weight gain. (2) Bingeing behavior induces extreme guilt, which patients resolve by various purging methods (self-induced vomiting; use of laxatives, diuretics, enemas), strict dieting or fasting, and/or extreme exercise. (2,8,9)
Unlike the binge-eating/purging AN patient, BN patients do not fall below 85% of ideal weight. (2) BN may also be characterized by impulsiveness and maladaptive behaviors, such as drug abuse, shoplifting, suicide attempts, and sexual promiscuity. (10)
ED-NOS describes patients who exhibit some but not all features of AN or BN. Examples are binge-eating disorder, in which patients engage in binge eating but not BN's compensatory behaviors; female patients with regular menses despite other AN symptoms; patients who purge after eating small amounts of food; and those who chew and spit out large amounts of food rather than swallow it. (2)
EPIDEMIOLOGY
In a culture dominated by images of extremely thin fashion models, the desirability of weight loss becomes an unavoidable message. In the CDC's 2001 Youth Risk Behavior Surveillance Survey, 62% of girls and 29% of boys said they were trying to lose weight (although only 6.9% and 14.2%, respectively, were actually overweight). Strategies ranged from healthful dietary changes to risky behaviors, such as fasting for 24 hours or longer, taking "diet" preparations, or engaging in self-induced vomiting or laxative use. (11)
AN is estimated to affect 0.5% of adolescent girls and young women; BN, from 1% to 5%. (12) In Western societies, ED-NOS reportedly occurs in 3% to 5% of the female population; this includes binge-eating disorder, which may account for 3% of patients believed to have BN. Further, anorectic and bulimic behaviors not meeting the DSM-IV-TR criteria (eg, occasional fasting or bingeing/purging) have been reported in 10% to 20% of adolescent girls.
Eating disorders' prevalence increased from the 1930s at least through 1990. (7) Once considered a unique phenomenon among females, eating disorders are now reported more frequently in males. Onset is usually later in boys than in girls. (12-14)
RISK FACTORS AND ASSOCIATED FEATURES
No isolated...
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