Anorexia nerviosa

The

new england journal

of

medicine

clinical practice

Anorexia Nervosa
Joel Yager, M.D., and Arnold E. Andersen, M.D.
This Journal feature begins with a case vignette highlighting a common clinical problem. Evidence supporting various strategies is then presented, followed by a review of formal guidelines, when they exist. The article ends with the authors’ clinicalrecommendations.

A 17-year-old girl is taken to her physician by worried parents. Never overweight, in the past six months she became determined to reduce from her baseline weight of 59.1 kg (130 lb). Her height is 1.7 m (5 ft 6 in.); her body-mass index (the weight in kilograms divided by the square of the height in meters) is 21. Through dieting and exercise, she lost 13.6 kg (30 lb) and stoppedmenstruating four months ago; her current body-mass index is 16. She denies having any problems and is annoyed that her parents, friends, and teachers are concerned. How should she be evaluated and treated?

the clinical problem
Anorexia nervosa is an eating disorder that usually begins in adolescence and is characterized by determined dieting, often accompanied by compulsive exercise, and, in asubgroup of patients, purging behavior with or without binge eating, resulting in sustained low weight. Other features include disturbed body image, heightened desire to lose more weight, and pervasive fear of fatness. The lifetime risk for the full disorder among women is estimated to be 0.3 to 1 percent (with a greater frequency of subclinical anorexia nervosa) and among men about a 10th of thatrate.1 The causes appear to be multifactorial, with determinants including genetic influences2; personality traits of perfectionism and compulsiveness3,4; anxiety disorders3-5; family history of depression and obesity; and peer, familial, and cultural pressures with respect to appearance.6 These contribute to an entrenched overvaluation of slimness, distorted perceptions of body weight, and phobicavoidance of many foods. The diagnostic criteria according to the Diagnostic and Statistical Manual of Mental Disorders, fourth edition7 (DSM-IV), are shown in Table 1. Most authorities are increasingly flexible with regard to the criteria requiring dieting to below 85 percent of normal body weight for age and height and a duration of amenorrhea of more than three months. Few differences arefound in the demographic characteristics and clinical features between patients who have the full syndrome of anorexia nervosa and those meeting all criteria except amenorrhea in female patients or decreased testosterone levels and diminished sex drive and function in male patients.8 Anorexia nervosa occurs in two types: food restricting, and binge eating and purging. The restricting type ischaracterized by marked caloric reduction, typically to 300 to 700 kcal per day, often accompanied by compulsive exercise. In the binging type, the binge may consist of food in a range from small amounts (“subjective” binge) to several thousands of calories. Purging usually begins after dieting commences, most commonly with the use of self-induced vomiting, or by abuse of laxatives, and occasionally withthe use of diet pills or diuretic agents. Other psychiatric conditions often coexist with anorexia nervosa, including major depression or dysthymia (in 50 to 75 percent of patients9), anxiety disorders (in more than 60 percent of patients10), and obsessive–compulsive disorder (in more than 40 percent of patients10). Alcohol or substance abuse may also be present (in 12 to 27 percent
n engl jmed 353;14 october 6, 2005

From the Department of Psychiatry, University of New Mexico School of Medicine, Albuquerque (J.Y.); and the Department of Psychiatry, University of Iowa School of Medicine, Iowa City (A.E.A.). Address reprint requests to Dr. Yager at the Department of Psychiatry, 1 University of New Mexico, MSC09 5030, Albuquerque, NM 87131-0001, or at jyager@unm.edu. N Engl J Med...