Chapter 076. Eating Disorders (Part 6) ppt

Chapter 076. Eating Disorders
(Part 6)

Table 76-3 Diagnostic Features of Bulimia Nervosa
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 given
The physical abnormalities associated with BN primarily result from the
purging behavior. Painless bilateral salivary gland hypertrophy (sialadenosis) may
be noted. A scar or callus on the dorsum of the hand may develop due to repeated
trauma from the teeth among patients who manually stimulate the gag reflex.
Recurrent vomiting and the exposure of the lingual surfaces of the teeth to
stomach acid lead to loss of dental enamel and eventually to chipping and erosion
of the front teeth. Laboratory abnormalities are surprisingly infrequent, but
hypokalemia, hypochloremia, and hyponatremia are observed occasionally.
Repeated vomiting may lead to alkalosis, whereas repeated laxative abuse may
produce a mild metabolic acidosis. Serum amylase may be slightly elevated due to
an increase in the salivary isoenzyme.
Serious physical complications resulting from BN are rare. Oligomenorrhea
and amenorrhea are more frequent than among women without eating disorders.
Arrhythmias occasionally occur secondary to electrolyte disturbances. Tearing of
the esophagus and rupture of the stomach have been reported and constitute life-
threatening events. Some patients who chronically abuse laxatives or diuretics
develop transient peripheral edema when this behavior ceases, presumably due to

high levels of aldosterone secondary to persistent fluid and electrolyte depletion.
Diagnosis
The critical diagnostic features of BN are repeated episodes of binge eating
followed by inappropriate and abnormal behaviors aimed at avoiding weight gain
(Table 76-3). The diagnosis of BN requires a candid history from the patient
detailing frequent, large eating binges followed by the purposeful use of
inappropriate mechanisms to avoid weight gain. Most patients with BN who
present for treatment are distressed by their inability to control their eating
behavior but are able to provide such details if queried in a supportive and
nonjudgmental fashion.
As in AN, there are two subtypes of BN. Patients with the "purging"
subtype utilize compensatory behaviors that directly rid the body of calories or
fluids (e.g., self-induced vomiting, laxative, or diuretic abuse), whereas those with
the "nonpurging" subtype attempt to compensate for binges by fasting or by
excessive exercise. Patients with the nonpurging subtype tend to be heavier and
are less prone to fluid and electrolyte disturbances.
Prognosis
The prognosis of BN is much more favorable than that of AN. Mortality is
low, 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). Cognitive
behavioral therapy (CBT) is a short-term (4–6 months) psychological treatment
that focuses on the intense concern with shape and weight, the persistent dieting,
and the binge eating and purging that characterize this disorder. Patients are
directed to monitor the circumstances, thoughts, and emotions associated with
binge/purge episodes, to eat regularly, and to challenge their assumptions linking
weight to self-esteem. CBT produces symptomatic remission in 25–50% of
patients.

Numerous double-blind, placebo-controlled trials have documented that
antidepressant medications are useful in the treatment of BN but are probably
somewhat less effective than CBT. Although efficacy has been established for
virtually all chemical classes of antidepressants, only the selective serotonin
reuptake inhibitor fluoxetine (Prozac) has been approved for use in BN by the U.S.
Food and Drug Administration. Antidepressant medications are helpful even for
patients with BN who are not depressed, and the dose of fluoxetine recommended
for BN (60 mg/d) is higher than that typically used to treat depression. These
observations suggest that different mechanisms may underlie the utility of these
medications in BN and in depression.
A subset of patients does not respond to CBT, antidepressant medication, or
their combination. More intensive forms of treatment, including hospitalization,
may be required.
Further Readings
American Psychiatri
c Association: Practice guidelines for the treatment of
patients 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 hypotha
lamic
amenorrhoea and anorexia nervosa. Lancet 366:74, 2005 [PMID: 15993236]
Katzman DK: Medical complications in adolescents with anorexia: A
review of the literature. Int J Eat Disord 37(Suppl):S52, 2005
Keski-Rahkonen A et al: Epidemiology and cours
e of anorexia nervosa in
the community. Am J Psychiatry 164(8):1259, 2007 [PMID: 17671290]
Klein DA, Walsh BT: Eating disorders: Clinical features and
pathophysiology. Physiol Behav 81:359, 2004 [PMID: 15159176]
Mehler PS: Clinical practice. Bulimia ne

rvosa. N Engl J Med 349:875,
2003 [PMID: 12944574]
Sysko R, Walsh BT: A critical evaluation of the efficacy of self-
help
interventions for the treatment of bulimia nervosa and binge-
eating disorder. Int J
Eat Disord Oct 5 2007, epub ahead of print
Yage
r J, Andersen AE: Clinical practice. Anorexia nervosa. N Engl J Med
353:1481, 2005 [PMID: 16207850]