Update on eating disorders: Binge-eating disorder
Where medications fit in the comprehensive treatment of obesity and depression
Clinical snapshot of BED
Managing patients with binge-eating disorder (BED) often requires behavioral, medical, and psychiatric interventions.
These patients suffer from recurrent episodes of distressing, uncontrollable overeating, but they do not purge or show other compensatory weight-loss behaviors common to bulimia nervosa1 and anorexia nervosa.2-10 As a result, they are often overweight or obese and may have obesity-related illnesses, such as hypertension or type 2 diabetes. Mild to severe depression—unipolar or bipolar—is a common psychopathology.
Because no one treatment fits all patients with binge eating disorder, their management usually requires an individualized program of:
- behavioral weight control
- and sometimes medications.
This article presents the evidence on which we base our comprehensive approach. General psychiatrists with knowledge of BED can treat patients with this eating disorder, although complicated cases may require referral for specialized treatment.
Figure 1 Medication options for uncomplicated BED
Psychiatric comorbidity. BED often occurs in patients with mood, anxiety, substance-abuse, impulsecontrol, and personality disorders.4,6,10-12 Mood disorder—particularly depression—appears to be the most common comorbidity. BED can occur with bipolar disorder12—a comorbidity that in our experience is underrecognized both clinically and in the literature.
Patients with BED and bipolar disorder show increased impulsivity and mood lability. As bipolar II disorder and other “soft-spectrum” forms are more common than bipolar I disorder, BED is also more likely to occur with hypomania than mania.
Overweight. Not surprisingly, BED is associated with overweight and obesity.5,8,9,11 Not all patients with BED are overweight or obese, but most who participate in clinical trials of BED treatments are at least overweight. BED has been reported in up to:
- 30% of participants in weight-loss programs7
- 70% of participants in groups such as Overeaters Anonymous
- 50% of patients who seek bariatric surgery.5
In our experience, patients are often more distressed by their weight than by their binge eating, depression, or anxiety. Indeed, overweight and obesity are the usual reasons patients with BED present for treatment at our center.
Diagnosis. BED’s validity as a clinical diagnosis has been controversial since the disorder was first included in DSM-IV (Table 1).3 Debate continues about some definitions in the DSM criteria, including what amount of food is “definitely larger” than most people would eat and what is “loss of control over eating.”
Nevertheless, screening for BED is relatively easy. Clinicians may use the eating disorder section of the Structured Clinical Interview for DSM-IV or the Eating Disorders Examination. Alternatively, simply ask patients if they have episodes of uncontrollable overeating, during which they eat unusually large amounts of food and their eating feels out of control.
Course. BED begins in adolescence or adulthood. Disease course is variable, with periods of remission, recurrence, and chronicity.6,7,10 Interestingly, one prospective study showed that even if the binge eating resolves, persons may still develop obesity.13
Prevalence. BED affects 1.5% to 3% of the U.S. population. It is more common in women than men, equally prevalent in whites and blacks, and more prevalent than anorexia nervosa and bulimia nervosa combined.11,14 Subthreshold BED—such as obesity with infrequent or nondistressing binge eating—appears to be much more common,10 although no data are available.
Theories of binge eating
BED’s cause is unknown, but biological, familial, and psychosocial factors have been implicated.
Biological factors. The neurotransmitters serotonin (5-HT) and dopamine—as well as various peptides—have been shown to help regulate feeding behavior.10
Diagnostic criteria for binge-eating disorder*
* Research criteria, DSM-IV-TR appendix B.
Source: Reprinted with permission from the Diagnostic and statistical manual of mental disorders, 4th edition, text revision. Copyright 2000. American Psychiatric Association.
Serotonin. Reduced 5-HT transporter binding has been shown in obese women with BED.15 Their 5-HT binding improved and binge eating subsided with group psychotherapy and fluoxetine, although the women continued to gain weight.
Figure 2 Medication options for BED with obesity and a mood disorder*
Dopamine. Obese patients who compulsively overeat may have lower levels of dopamine D2 receptors than do normal-weight controls.16
Genetic factors. In severely obese patients (body mass index 44±2), those with a DSM-IV diagnosis of BED exhibited mutations of the melanocortin 4 receptor gene, which affects the anorectic properties of alpha melanocyte-stimulating hormone.17
Familial factors associated with BED include parental depression and obesity.18
Psychosocial correlates include physical and sexual abuse, bullying by peers, and discrimination because of being overweight.19
Few systematic studies have examined BED treatment. Emerging research suggests that behavioral weight-loss treatment, specialized psychotherapies, and medications may be effective in some patients with BED.4,6,8
Over the short term (<1 year), behavioral weight-loss treatment produces similar weight loss in obese patients with or without BED; long-term results in both groups, however, have not been satisfactory.20,21 No studies have examined the efficacy of specialized diets (such as low-carbohydrate regimens) in patients with BED.
Specialized psychotherapy’s goal is to modify bingeeating behavior with behavioral self-management strategies, reducing interpersonal dysfunction and stress, and/or managing affective dysregulation.
Cognitive-behavioral therapy (CBT) and interpersonal therapy (IPT) have been effective in reducing binge eating, both acutely and for up to 12 months 4,20-24 but less effective in achieving and maintaining weight loss. Patients who achieve remission in binge eating after undergoing CBT or IPI often experience modest but stable weight loss.20-22 For example, in a comparison study of CBT and IPT:
- After 20 weekly sessions, patients whose binge eating was in remission lost weight (mean body mass index [BMI] −0.5 ± 1.5 kg/m2), whereas those who continued to binge gained weight (mean BMI +0.4 ±2.0 kg/m2).
- At 12 months’ follow-up, patients still in remission continued to lose weight (mean BMI −1.0 ± 3.0 kg/m2), whereas those no longer in remission gained weight (mean BMI +0.7 ±2.9 kg/m2[P = 0.01]).22
Self-help and dialectical behavioral therapy (DBT) may also help reduce binge eating in BED. As with CBT and IPT, they are less effective in weight loss. In the only controlled study of DBT,24 patients achieved an average 2.5-lb weight loss after 20 weeks of DBT, compared with an average 0.6-lb weight gain in the control group. This difference was not significant, and the report did not include data on weight loss maintenance.
In summary, CBT may be more effective than behavioral weight loss treatment for reducing binge eating, but behavioral weight loss is more effective for weight loss.
Medications for BED
- BED is often associated with depressive symptoms and disorders.
- BED is related to bulimia nervosa, and placebo-controlled trials have shown that the binge eating of bulimia nervosa responds to several classes of antidepressants. The selective serotonin reuptake inhibitor (SSRI) fluoxetine is the only medication indicated for treating any eating disorder (bulimia nervosa).
- Bupropion and venlafaxine—a serotonin-norepinephrine reuptake inhibitor (SNRI)—have weight-loss properties.
SSRIs are the most extensively studied antidepressants for treating BED. SSRIs have weightloss properties, but only short term.25-26 Citalopram, fluoxetine, fluvoxamine, and sertraline have reduced binge eating and body weight more effectively than placebo during 6 to 9 weeks of treatment (Table 2).25-26 However, one controlled study23 showed that fluoxetine was not significantly more effective than placebo in reducing binge frequency or body weight after 16 weeks.
TCAs. Studies of tricyclic antidepressants (TCAs) for BED are sparse, and results have been mixed. In one trial, imipramine was similar to placebo in reducing binge frequency and body weight. In a placebo-controlled study of patients with nonpurging bulimia nervosa, desipramine reduced binge eating but had no effect on body weight.25,26
Drug therapies shown to be effective for BED*
20 to 60
20 to 80
50 to 300
50 to 200
50 to 600
− No improvement
* Randomized, controlled trials. Antidepressants were studied in patients with BED; sibutramine and topiramate were studied in patients with BED and associated obesity.
† One 16-week trial of fluoxetine for BED (reference 23) did not show statistically significant differences in post-treatment binge frequency or body-mass index.
Venlafaxine. In a retrospective review of 35 consecutive obese women with BED, venlafaxine, mean 222 mg/d for 28 to 300 days (median 120 days), reduced binge eating, body weight, and depressive symptoms.27
Bupropion has been more effective than placebo for treating:
- uncomplicated obesity (short- and long-term)
- obesity associated with depressive symptoms
- bulimia nervosa (although bupropion is contraindicated in these patients because of seizure risk).26,28,29
No controlled trials have studied bupropion for BED. When using dosages effective in depressive disorders, we find bupropion helpful in reducing binge eating, body weight, and depressive symptoms in BED patients.
Appetite suppressants decrease appetite and weight, may increase satiety, and may reduce depressive symptoms.
Sibutramine—a serotonin, norepinephrine, and dopamine reuptake inhibitor indicated for managing obesity—has been reported effective in BED in a 12-week, randomized, double-blind, placebo-controlled trial. A 15-mg/d dosage reduced binge frequency, body weight, and depressive symptoms more effectively than placebo in 60 obese patients with BED.30 Most-frequent adverse effects (dry mouth and constipation) were mild and benign, and no significant complications were observed.
Sibutramine’s mechanism of action in BED is unknown. However, it suppressed food intake during binge-eating episodes in patients with BED in a randomized, controlled, cross-over laboratory study.31
Orlistat. We know of no published controlled studies of the lipase inhibitor orlistat in treating BED. In our experience, some patients do well with this agent, though we have observed infrequent purging episodes with it in patients with BED.
With orlistat, 120 mg tid, our BED patients have experienced weight loss comparable to that seen in uncomplicated obesity at similar dosages. Orlistat seems most effective for:
- patients whose binge eating is in remission
- those who responded to behavioral weightloss treatment, a psychological treatment, or another medication.
Anticonvulsants such as topiramate and zonisamide have been shown effective in treating obesity32,33 and are sometimes used to treat BED. Obese BED patients with mood disorders often do best with psychotherapy plus medication
Topiramate at dosages of 50 to 600 mg/d (median 212 mg/d) reduced binge-eating frequency, obsessive-compulsive features of binge eating, and body weight more effectively than placebo in a 14-week study of 61 obese patients with BED. These effects were maintained across 48 weeks in an open-label extension trial.34
Zonisamide, mean 513 mg/d, produced similar results during a prospective, open-label, 12-week trial in 15 patients with BED.35 A controlled trial to replicate these findings is ongoing.
BED may respond to anticonvulsant therapy for several reasons:
- Some anticonvulsants are effective in treating bipolar disorder, which may occur with BED.12
- Some anticonvulsants have shown benefit in conditions associated with pathologic impulsivity, such as substance abuse, impulse-control, and cluster B disorders.10
Growing evidence shows that bulimia nervosa and BED may be associated with pathologic impulsivity.
Combination therapies are generally more effective than monotherapies in patients with mood disorders, uncomplicated obesity, and possibly bulimia nervosa. Even so, few trials have systematically studied combination therapy in managing patients with BED.