Update on eating disorders Bulimia nervosa: Persistent disorder requires equally persistent treatment

Thousands of scientific papers have been written about bulimia, but not all patients receive effective treatments that produce remission.

To set the record straight and help psychiatrists avoid undertreating bulimia, this article discusses:

• evidence for using antidepressants, even when patients are not “depressed”
• merits of psychotherapies, including those shown to work and those that can harm
• augmentation therapies that can help increase response from partial to full remission.

Initial evaluation

Diagnosis. Bulimia nervosa is characterized by eating binges, followed by purging behaviors such as self-induced vomiting or laxative abuse^1,2 (Table 1). It affects 1% to 3% of adolescent girls and young women and occurs in women 5 to 10 times more often than in men.

Bulimia is often persistent. About one-half of bulimic patients—including those who have been treated—continue to show eating disorder features on long-term follow-up.^3,4

Psychiatric comorbidity. Most bulimic patients report a history of other psychiatric disorders, especially major depressive and bipolar disorders and anxiety disorders such as panic disorder, social phobia, and obsessive-compulsive disorder (OCD).⁵ Because these psychiatric comorbidities may occur before, during, or after bulimia nervosa, one cannot assume that mood or anxiety disorders are a cause or consequence of bulimia. Instead, bulimia nervosa, mood disorders, and anxiety disorders may be different expressions of a shared etiologic abnormality.

Table 1

DSM-IV-TR diagnostic criteria for bulimia nervosa

Evidence supporting this hypothesis comes from studies showing that these disorders:

• respond to several chemically unrelated families of antidepressants^6,7
• frequently co-occur in individual patients^5,7
• frequently co-aggregate in families.^7-9

We have published this evidence^6,7 and proposed that bulimia nervosa may be one form of a larger underlying disorder, which we termed “affective spectrum disorder.”

Antidepressants are often rapidly effective in treating bulimic symptoms,¹⁰ regardless of whether patients exhibit depressive symptoms. Thus, there is no reason to withhold antidepressant therapy simply because a bulimic patient is not depressed. The term “antidepressant” may be a misnomer; these drugs are effective for numerous conditions, of which depression is only one.

Anorexic symptoms. Co-occurring depressive or anxiety disorders in a bulimic patient will not greatly alter treatment. The antidepressants and psychotherapies typically used to treat bulimia are often equally effective for affective disorders. Co-occurring anorexia nervosa, however, is a more serious concern.

Bulimic patients often display a history of anorexia nervosa; in many cases, the patient develops anorexia nervosa as a teenager and then progresses to bulimia nervosa across several years. Her prognosis is much better if her weight normalizes with the shift to bulimia nervosa, than if her weight remains well below normal for her height. It is unclear why medications and psychotherapy are much less effective in bulimic patients with anorexic symptoms than in those with bulimia alone. Watch for further details on anorexia nervosa as this series continues in future issues of.

Medical considerations. Potential medical complications—mostly consequences of vomiting or laxative use—are important to consider when you assess a bulimic patient:¹

• The acid in vomitus may gradually erode tooth enamel, requiring dental consultation.
• Vomitus may inflame salivary gland ducts, though the swelling is usually benign.
• Frequent vomiting may result in hypokalemia and alkalosis, although aggressive medical treatment usually is not needed.

Ask about ipecac use. To induce vomiting, some patients may abuse ipecac syrup, which can cause cardiomyopathy.¹¹

Inpatient or outpatient? Unless the bulimic patient displays severe and medically dangerous anorexic symptoms, she can usually be treated as an outpatient. However, evaluate her carefully for suicidal ideation—which is not uncommon in bulimia nervosa—and consider inpatient treatment if necessary.

Medication vs. psychotherapy

The relative merits of medication versus psychotherapy in treating bulimia nervosa continue to be debated. The Cochrane Database of Systematic Reviews includes meta-analyses of both drug therapy¹² and psychotherapy¹³ for bulimia nervosa. The 2001 drug therapy review found that “the use of a single antidepressant agent was clinically effective,” with no one drug clearly superior to another. Notably, this review was published before recent findings on topiramate.