The Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) categorizes eating disorders as anorexia nervosa (AN), bulimia nervosa (BN), and eating disorder not otherwise specified (ED-NOS). AN is characterized by an intense fear of gaining weight, refusal to maintain a normal body weight, disturbed perception of one’s own shape or size, and, if female, amenorrhea of at least three consecutive cycles. Individuals lacking insight are frequently brought to professional attention by a family member after marked weight loss. AN is subcategorized as either restrictive eating or binge-eating/purging type with self-induced vomiting, misuse of laxatives, diuretics, or enemas. Up to 50% of patients with AN develop bulimic symptoms, and some patients who are initially bulimic develop anorexic symptoms. Psychiatric comorbidities include depressive symptoms like sadness, social withdrawal, irritability, insomnia, or decreased sexual interest. These may be secondary to physiological sequelae of semi-starvation and resolve only after partial or complete weight restoration. Obsessive-compulsive features like frequent thoughts of food, hoarding food, picking/pulling apart small portions of food, or collecting recipes, along with anxiety and concerns of eating in public, are common. Other comorbid conditions include substance abuse, sexual abuse, and bipolar disorder.
Although AN frequently begins in the midteens, the onset is in the early 20s for 5% of patients. Estimates of male-to-female ratio range from 1:6 to 1:10. The reported lifetime prevalence of AN among women has ranged from 0.5% when narrowly defined to 3.7% for more broadly defined AN. Eating disorders are more frequent in industrialized societies, where there is an abundance of food and being thin, especially for females, is considered attractive. In the United States, eating disorders are common in young Hispanic, Native American, and African American women, but the rates are still lower than in Caucasian women. Female athletes involved in running, gymnastics, or ballet dancers, male body builders and wrestlers are also at increased risk. Biological and psychosocial factors are implicated in the cause of anorexia, but the etiology and underlying mechanisms of eating disorders remain unknown. Antidepressants often benefit patients with AN and implicate a role for serotonin and norepinephrine. Starvation results in many biochemical changes such as hypercortisolemia, nonsuppression of dexamethasone, suppression of thyroid function, and amenorrhea. Monozygotic twins, other first-degree female relatives, and children of patients as well as low levels of nurturance and empathy are reported in families of children presenting with eating disorders. In addition to the clinical interview, rating scales such as the Eating Attitudes Test, Eating Disorders Inventory, or Body Shape Questionnaire can be used for assessment of eating disorders.
Medical comorbidity and complications of AN are related to weight loss, starvation, purging, and laxative abuse. Generalized weakness, dehydration, electrolyte and cardiac rhythm abnormalities, and amenorrhoea are common. AN should be differentiated from malignancy, seizures, AIDS, depressive disorders, somatization disorder, schizophrenia, and BN.
A comprehensive treatment plan includes a combination of good nutritional rehabilitation, psychotherapy, and medications. Weight, cardiac, and metabolic status of the individual with AN determine the acuity of the illness and the need for hospitalization. Aims of treatment are to restore the patient’s nutritional status by establishing healthy eating patterns, treat medical complications, correct core dysfunctional ideations related to eating disorders, enlisting family support, and providing for family counseling. Medications for treatment of AN can be initiated before or after weight gain. Medications can maintain normal eating behaviors as well as treat associated depressive or obsessivecompulsive symptoms. Antidepressants like the serotoninspecific reuptake inhibitors, for example, fluoxetine (Prozac), are commonly considered. Low doses of antipsychotics for marked agitation with psychotic thinking and benzodiazepene anxiolytics for extreme anticipatory anxiety are helpful. Long-term follow-up shows recovery rates ranging from 44% to 76% with mortality of up to 20% primarily from cardiac arrest or suicide.