Chapter 076. Eating Disorders (Part 6)

Recurrent episodes of binge eating, which is characterized by the consumption of a large amount of food in a short period of time and a feeling that the eating is out of control.Recurrent inappropriate behavior to compensate for the binge eating, such as self-induced vomiting.The occurrence of both the binge eating and the inappropriate compensatory behavior at least twice weekly, on average, for 3 months.Overconcern with body shape and weight.Note: If the diagnostic criteria for anorexia nervosa are simultaneously met, only the diagnosis of anorexia nervosa is givenThe physical abnormalities associated with BN primarily result from the purging behavior....
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Chapter 076. Eating Disorders (Part 6) Chapter 076. Eating Disorders (Part 6) Table 76-3 Diagnostic Features of Bulimia Nervosa Recurrent episodes of binge eating, which is characterized by theconsumption of a large amount of food in a short period of time and a feeling thatthe eating is out of control. Recurrent inappropriate behavior to compensate for the binge eating, suchas self-induced vomiting. The occurrence of both the binge eating and the inappropriatecompensatory behavior at least twice weekly, on average, for 3 months. Overconcern with body shape and weight. Note: If the diagnostic criteria for anorexia nervosa are simultaneously met,only the diagnosis of anorexia nervosa is given The physical abnormalities associated with BN primarily result from thepurging behavior. Painless bilateral salivary gland hypertrophy (sialadenosis) maybe noted. A scar or callus on the dorsum of the hand may develop due to repeatedtrauma from the teeth among patients who manually stimulate the gag reflex.Recurrent vomiting and the exposure of the lingual surfaces of the teeth tostomach acid lead to loss of dental enamel and eventually to chipping and erosionof the front teeth. Laboratory abnormalities are surprisingly infrequent, buthypokalemia, hypochloremia, and hyponatremia are observed occasionally.Repeated vomiting may lead to alkalosis, whereas repeated laxative abuse mayproduce a mild metabolic acidosis. Serum amylase may be slightly elevated due toan increase in the salivary isoenzyme. Serious physical complications resulting from BN are rare. Oligomenorrheaand amenorrhea are more frequent than among women without eating disorders.Arrhythmias occasionally occur secondary to electrolyte disturbances. Tearing ofthe esophagus and rupture of the stomach have been reported and constitute life-threatening events. Some patients who chronically abuse laxatives or diureticsdevelop transient peripheral edema when this behavior ceases, presumably due tohigh levels of aldosterone secondary to persistent fluid and electrolyte depletion. Diagnosis The critical diagnostic features of BN are repeated episodes of binge eatingfollowed by inappropriate and abnormal behaviors aimed at avoiding weight gain(Table 76-3). The diagnosis of BN requires a candid history from the patientdetailing frequent, large eating binges followed by the purposeful use ofinappropriate mechanisms to avoid weight gain. Most patients with BN whopresent for treatment are distressed by their inability to control their eatingbehavior but are able to provide such details if queried in a supportive andnonjudgmental fashion. As in AN, there are two subtypes of BN. Patients with the purgingsubtype utilize compensatory behaviors that directly rid the body of calories orfluids (e.g., self-induced vomiting, laxative, or diuretic abuse), whereas those withthe nonpurging subtype attempt to compensate for binges by fasting or byexcessive exercise. Patients with the nonpurging subtype tend to be heavier andare less prone to fluid and electrolyte disturbances. Prognosis The prognosis of BN is much more favorable than that of AN. Mortality islow, and full recovery occurs in approximately 50% of patients within 10 years.Approximately 25% of patients have persistent symptoms of BN over many years.Few patients progress from BN to AN. Bulimia Nervosa: Treatment BN can usually be treated on an outpatient basis (Fig. 76-1). Cognitivebehavioral therapy (CBT) is a short-term (4–6 months) psychological treatmentthat focuses on the intense concern with shape and weight, the persistent dieting,and the binge eating and purging that characterize this disorder. Patients aredirected to monitor the circumstances, thoughts, and emotions associated withbinge/purge episodes, to eat regularly, and to challenge their assumptions linkingweight to self-esteem. CBT produces symptomatic remission in 25–50% ofpatients. Numerous double-blind, placebo-controlled trials have documented thatantidepressant medications are useful in the treatment of BN but are probablysomewhat less effective than CBT. Although efficacy has been established forvirtually all chemical classes of antidepressants, only the selective serotoninreuptake inhibitor fluoxetine (Prozac) has been approved for use in BN by the U.S.Food and Drug Administration. Antidepressant medications are helpful even forpatients with BN who are not depressed, and the dose of fluoxetine recommendedfor BN (60 mg/d) is higher than that typically used to treat depression. Theseobservations suggest that different mechanisms may underlie the utility of thesemedications in BN and in depression. A subset of patients does not respond to CBT, antidepressant medication, ortheir combination. More intensive forms of treatment, including hospitalization,may be required. Further Readings American Psychiatric Association: Practice guidelines for the treatment ofpatients with eating disorders, third edition. Am J Psychiatry, 2006 Chan JL, Mantzoros CS: Role of leptin in energy-deprivation states:Normal human physiology and clinical implications for hypothalamicamenorrhoea and anorexia nervosa. Lancet 366:74, 2005 [PMID: 15993236] Katzman DK: Medical complications in adolescents with anorexia: Areview of the literature. Int J Eat Disord 37(Suppl):S52, 2005 Keski-Rahkonen A et al: Epidemiology and course of anorexia nervosa inthe community. Am J Psychiatry 164(8):1259, 2007 [PMID: 17671290] Klein DA, Walsh BT: Eating disorders: Clinical features andpathophysiology. Physiol Behav 81:359, 2004 [PMID: 1 ...