Eating disorders are complex illnesses that affect adolescents with increasing frequency. They rank as the third most common chronic illness in adolescent females (1), with an incidence of up to 5% (2,3), a rate that has increased dramatically over the past three decades. Two major subgroups of the disorders are recognized: a restrictive form, in which food intake is severely limited (anorexia nervosa), and a bulimic form, in which binge eating episodes are followed by attempts to minimize the effects of overeating via vomiting, catharsis, exercise or fasting (bulimia nervosa). Both anorexia nervosa and bulimia nervosa can be associated with serious biological, psychological and sociological morbidity, and significant mortality.

Although eating disorders occur most frequently in adolescents, reports in the scientific literature often combine findings from adolescents with those from adults or report exclusively on adult samples. Unique features of adolescents and the developmental process of adolescence are often critical considerations in determining the diagnosis, treatment or outcome of eating disorders. Consequently, adolescents need to be considered separately and differentiated from adult patients with eating disorders.

This position statement addresses the key issues distilled from the scientific literature and represents a consensus of numerous specialists in adolescent medicine regarding the diagnosis and management of adolescents with eating disorders.

Diagnosis
Diagnostic criteria for eating disorders such as described in DSM-IV (4) may not be entirely applicable to adolescents. The wide variability in the rate, timing and magnitude of both height and weight gain during normal puberty; the absence of menstrual periods in early puberty along with the unpredictability of menses soon after menarche; and the lack of psychological awareness regarding abstract concepts (such as self-concept, motivation to lose weight or affective states) owing to normative cognitive development limit the application of those formal diagnostic criteria to adolescents. In addition, clinical features such as pubertal delay, growth retardation or the impairment of bone mineral acquisition may occur at subclinical levels of eating disorders (5,6). The use of strict criteria may preclude the recognition of eating disorders in their early stages and subclinical form (a prerequisite for primary or secondary prevention), and may exclude some adolescents with significantly abnormal eating attitudes and behaviours, such as those who vomit or take laxatives regularly but do not binge (7-9). Finally, abnormal eating habits may result in significant impairment in health (10), even in the absence of fulfilment of formal criteria for an eating disorder. For all of these reasons, it is essential to diagnose eating disorders in adolescents in the context of the multiple and varied aspects of normal pubertal growth, adolescent development and the eventual attainment of a healthy adulthood rather than by merely applying formalized criteria.

Position: In clinical practice, the diagnosis of an eating disorder should be considered in an adolescent patient who engages in potentially unhealthy weight control practices and/or demonstrates obsessive thinking about food, weight, shape or exercise and not only in one who meets established diagnostic criteria. In such adolescents, an eating disorder should be considered if the teenager fails to attain or maintain a healthy weight, height, body composition or stage of sexual maturation for sex and age.

Medical complications

No organ system is spared the effects of eating disorders (11-15). Although the physical signs and symptoms occurring in a patient are primarily related to the weight control behaviours practised, the health care professional must consider their frequency, intensity and duration, as well as the biological vulnerability conferred by the sexual maturity of the patient. The majority of physical complications in adolescents with an eating disorder appear to improve with nutritional rehabilitation and recovery from the eating disorder, but some may be potentially irreversible. The long term consequences are still to be elucidated.

Medical complications in adolescents that are potentially irreversible include growth retardation if the disorder occurs before closure of the epiphyses (15-18); pubertal delay or arrest (6,16,17); and impaired acquisition of peak bone mass during the second decade of life (6,20,21), increasing the risk of osteoporosis in adulthood. These features emphasize the importance of medical management and ongoing monitoring by physicians who understand normal adolescent growth and development.

Just as we endorse early recognition of eating disorders through the use of broad developmentally appropriate criteria, we also endorse early intervention to prevent, limit or ameliorate medical complications, some of which are life-threatening. Adolescents who restrict food intake, vomit, purge or binge in any combination, with or without severe weight loss, require treatment even if they do not meet strict criteria for an eating disorder.

Position: Because of the potentially irreversible effects of an eating disorder on physical and emotional growth and development in adolescents, because of the risk of death and because of evidence suggesting improved outcome with early treatment, the threshold for intervention in adolescents should be lower than in adults. Ongoing medical monitoring should continue until the adolescent has demonstrated a return to both medical and psychological health.