Stephan, Herpertz, Ulrich, Hagenah, Silja, Vocks, Jörn, von Wietersheim, Ulrich, Cuntz, Almut, Zeeck, and Martina, de Zwaan
The main symptom of anorexia nervosa (AN) is self-induced malnutrition with weight loss that may amount to cachexia. According to the diagnostic criteria, the body weight is so low that health impairment is to be feared. In adults, this danger is seen when the body mass index (BMI) drops below 17.5kg/m2; in children and adolescents, it corresponds to being below the 10th BMI-for-age percentile. Since children have a much smaller fat mass than adults or adolescents, the somatic sequelae of starving during AN occurring early in life are more serious and have negative consequences for, e.g., bone density, growth in height, and cerebral maturation. AN is often accompanied by other psychological illnesses such as depression, anxiety, or compulsive disorder. The average frequency of AN in young women aged between 14 and 20 years varies between 0.2% and 0.8% (1) (eBox 1). eBox 1 ICD-10 diagnostic criteria for anorexia nervosa (F 50.0) (2) Actual body weight at least 15% below expected weight, or body mass index 17.5 or less (in adults). Weight loss is caused by the avoidance of high-calorie foods and at least one of the following: Self-induced vomiting Self-induced purging Excessive exercise Use of appetite suppressants and/or diuretics Distorted body image as a specific psychological disorder Endocrine disorder, manifest in the female as amenorrhea and in the male as a loss of libido If onset is prepubertal, the puberty in boys and girls may be delayed (growth ceases; in girls the breasts do not develop) The 10-year mortality in this group is around 5%. This is considerably more than 10 times the mortality from other causes in this age group in the general population (1, 2). Follow-up studies have shown that around 40% of patients with AN show good treatment success, while 25% have moderate and 30% poor treatment success (3). The term “bulimia nervosa” (BN) refers to the uncontrollable urge for frequent high-calorie food. Episodes of excessive uncontrolled eating alternate with rigorous fasting, vomiting, and abuse of laxatives and/or diuretics. At 2%, BN has a notably higher prevalence than AN. Both of these eating disorders affect women in the large majority of cases; men are affected in only 5% to 10% of cases (1) (eBox 2). eBox 2 ICD-10 diagnostic criteria for bulimia nervosa (F 50.2) (2) The constant obsession with eating and the overwhelming desire for food leads to episodes of eating large amounts of food in short time periods. There are efforts made to reduce the effect of eating foods perceived as fattening in the form of self-induced vomiting and other purging techniques, alternating episodes of calorie restriction, using appetite suppressants, thyroid preparations or diuretics. People with diabetes may refrain from using their insulin treatment. There is an intense fear of becoming fat, which leads to the desire to reach a specific body weight much lower than is considered normal or healthy for height and age. In many cases, the bulimia follows an episode of anorexia nervosa, although the period of time between the two disorders may vary considerably. According to studies in the USA, about 50% of patients with BN are free of symptoms after more than 5 years, while about 20% continue to fulfill all the criteria of the disorder (4). The diagnosis “binge eating disorder” (BED) was incorporated by the American Psychiatric Association in the fourth revision of the Diagnostic and Statistic Manual of Mental Disorders (DSM-IV) in 1994 (5); in the International Classification of Diseases (ICD-10) it can only be coded under the category “eating disorder, unspecified” (F50.9). The course of BED has been the object of less research than AN and BN, but its prognosis is better. Remission rates in outpatient psychotherapy range between 50% and 80% (5– 7) (eBox 3). eBox 3 Diagnostic criteria for binge eating disorder (7) Recurring episodes of binge eating. The two characteristics of a binge eating episode are: Eating a much larger amount of food than most people would consider normal under similar circumstances and within the same time frame (eating may continue for several hours). While eating, there is a feeling of loss of control over the amount of food or type of food being consumed. Binge eating episodes are related to at least three of the following: Eating until feeling uncomfortably full. Eating large quantities of food when not even hungry. Eating noticeably faster than is considered normal. Eating alone due to embarrassment of overeating. Feelings of disgust, depression, or guilt after a binge. There is obvious distress concerning binge eating behavior. On average, binge eating takes place twice weekly, and has done so for 6 months. There are no recurring efforts to compensate for binge eating, such as purging or excessive exercise. The disorder occurs at times other than during episodes of anorexia nervosa or bulimia nervosa. The prevalence of BED varies in the general population between 0.7% (8) and 4.3% (9); women are affected about 1.5 times as often as men (10). The eating disorders AN and BN are of great social significance because they almost exclusively affect young people—with serious consequences for their physical and mental health. Overall, eating disorders give rise to enormous direct and indirect costs. Costs of 5300 EUR for AN and 1300 EUR for BN per patient per year are to be expected. Haas et al. (11) calculated an average of 4647 EUR in inpatient costs per patient. Krauth et al. (12) calculated overall costs of 12 800 EUR for a patient with AN. These costs are way above the average costs for inpatients with other diseases. So far as the authors know, no cost analyses have yet been done for BED.