Ask the Expert: Eating Disorders

I am in an office practice with several psychiatrists in a midsize city. None of us received training in medical school, or afterward, about eating disorders. Recently, several patients in our practice have been diagnosed with eating disorders and we expect we will see more. Although none of us plans to specialize in eating disorders, how should we prepare to manage these patients?

This is an excellent question because eating disorders are common, lethal, and treatable. The three major eating disorders described in the DSM-5 are: anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). It is estimated that 11.7% of the population in the United States will suffer from an eating disorder at some time during their lives (1). Thus, in a midsize city with a population of 300,000, over 35,000 people are eventually likely to be affected. The chances of dying prematurely from AN is more than five times higher than among the general population and almost twice as high among patients with BN (2). Treatment is more effective than usually recognized. One method of assessing the results of randomized clinical trials is the concept of number needed to treat (NNT). The NNT is the number of people who must be treated to result in benefit to one person. For example, for BN, the NNT with cognitive-behavioral therapy (CBT) is three (3); for AN, the NNT with family-based treatment is five (4); and for BED, the NNT with fluoxetine is six (5).

Assessment

As physicians, psychiatrists are uniquely poised to evaluate and manage many patients with eating disorders because these patients commonly have complex medical and psychiatric problems that interact with one another. The first step in managing eating disorder patients is a thorough assessment, which includes a detailed psychiatric and medical history, mental status examination, physical examination, and laboratory testing (6).

Key components of a comprehensive history of the eating disorder include weight and binge-eating history, nutritional status, and methods of weight control (including restrictive eating, purging by vomiting, abuse of laxatives, diuretics, or diet pills, and over-exercise). Assessment for common comorbid psychiatric disorders includes obsessive-compulsive disorder (particularly in patients with AN), substance use disorders (especially among chronically ill patients), depressive disorders (in all three major eating disorders), and bipolar disorder (especially in BN patients).

Symptoms and signs of common physiological complications include dental caries, parotid gland enlargement, arrhythmias, chest pain, shortness of breath, delayed gastric emptying, gastroesophageal reflux disorder, constipation, amenorrhea, loss of libido, poor concentration, and lanugo. Physical examination should include weight in a hospital gown on a balance beam scale, measured height, supine and standing blood pressure and heart rate, and oral temperature. Body mass index should be determined.

Laboratory testing should include, at a minimum, a complete blood count, comprehensive metabolic profile, and thyroid function tests. Most patients with AN or BN also need an electrocardiogram, because cardiac abnormalities commonly occur, especially if there are electrolyte abnormalities. AN patients who are ill longer than 6 months should have a bone mineral density assessment.

Patients with eating disorders are often reluctant to accept treatment. The family may be very effective in encouraging patients to receive treatment, particularly when recommended both by the psychiatrist and the primary care physician. However, there are times when the patient may refuse treatment and be so ill that court commitment for treatment is required. Length of hospitalization has been reported to be longer for committed patients than for voluntary patients, but early outcomes appear to be equally positive (7).

Treatment

Therapeutic Use of Signs, Symptoms, and Laboratory Data

Interpretation of results of the evaluation with the patient can be a pivotal point in their management. As physicians, psychiatrists are uniquely able to help patients make the connection between behavior (e.g., restrictive eating or purging) and signs, symptoms, and laboratory test results. For example, restrictive eating results in weight loss and amenorrhea that contribute to the development of osteopenia, an unwanted physiological complication for most patients. Another example would be purging by vomiting (a behavior that can result in hypokalemia and predispose to potentially fatal cardiac arrhythmias). This psychotherapeutic use of signs, symptoms, and laboratory tests is a strategy that can often aid the patient in overcoming denial and facilitate entry into formal treatment.

Cognitive-Behavioral Therapy: Bulimia Nervosa and Binge Eating Disorder

Cognitive-behavioral therapy is the most effective treatment for BN and can be provided in individual or group sessions over the course of 8–20 weeks (8). There are three phases to classic CBT–BN. The first phase is education about the theory underlying the maintenance of disturbed eating and dysfunctional weight control behavior (for example, restrictive eating, purging by vomiting, laxative abuse, or over-exercise). Using a diary format, the second phase is geared to identifying the frequency and timing of the problematic behavior. Events or factors preceding and following these behaviors are identified and recorded. The third phase is finding ways to alter the problematic behavior unique to the patient utilizing a specific sequence of behavioral tasks and “experiments.” Between 30% and 50% of patients who start classic CBT treatment cease binge eating and purging, but the rest either drop out of treatment or achieve a reduction, but not a cessation, of binge eating and purging. In the last few years CBT has been enhanced (CBT-E) to promote recovery in patients who have comorbid disorders (9). Strategies are included designed to impact core low self-esteem and promote coping with interpersonal life. Although there are self-help manuals that are very useful, the most effective outcomes are with experienced therapists who have received specialized training in CBT.

CBT has been studied for patients with AN and with BED (10). Thus far, the evidence for effectiveness in AN is weak. However, CBT for BED is effective in reducing episodes of binge eating; but among the large minority who are overweight or obese, CBT is not helpful in weight reduction.

Cognitive-Behavioral Therapy: Guided and Manualized Self-Help for Binge Eating Disorder and Bulimia Nervosa

Although manualized self-help is not as effective as individual or group treatment led by trained therapists, reduction in symptoms can occur; however, nonadherence and high drop-out rates are common. Patients with BED are more likely to complete self-help and more likely to benefit than are patients with BN. Guidance by health care professionals can improve the outcome in patients with BN (11).

Medications

Fluoxetine (trade name Prozac) is the only medication approved by the Food and Drug Administration (FDA) for any of the three major eating disorders. It is a selective serotonin reuptake inhibitor. It is only approved for BN at a recommended dose of 60 mg for adults only, although it is often effectively used off-label for adolescents with BN. Unfortunately, it is often used inappropriately for underweight AN patients; several studies have found fluoxetine to be ineffective in AN. This may be because some underweight AN patients have inadequate intake of 5-hydroxytryptophan (an amino acid) that is thought to be a precursor to serotonin. If this results in low levels of serotonin in the brain, a medication that inhibits reuptake of serotonin would be expected to be ineffective.

Multiple medications have been tried for AN including the atypical antipsychotics, but the results have been disappointing (12). Although in one randomized placebo-controlled trial (13) olanzapine was found to decrease minimally the length of time required to achieve ideal body weight, few eligible patients agreed to participate in the trial and the drop-out rate was high. The drug is generally unacceptable to patients because it can cause weight gain. Very few placebo-controlled randomized drug trials have been completed with AN patients.

Although there are currently no FDA-approved medications for BED, research in this area is active (14). Multiple antidepressants, especially the selective serotonin reuptake inhibitors, have been found to reduce binge eating in the short term, but in the large minority of patients who are overweight or obese, weight loss has not occurred. Although topiramate has been found to reduce both binge eating and weight, there are serious side effects that limit its usefulness including trouble concentrating, word-finding difficulty, and metabolic acidosis.

Family-Based Treatment for Anorexia Nervosa

This exciting recent development utilizes the family to promote weight restoration among adolescents with AN (15). There are three phases to treatment. In the first phase, the parents take over control of the eating of the adolescent and, using guidance from the family therapist, ensure consumption of the prescribed calories until weight gain is steady and close to ideal body weight. In the second phase, control of eating is gradually transferred to the adolescent. In the third phase, individual therapy with the adolescent begins with the goal of ensuring achievement of appropriate developmental steps.

The first phase of this treatment cannot usually be provided in a general psychiatric practice because multiple lengthy sessions are often necessary, including direct supervision of meals in the presence of the family therapist. However, by the time the second phase begins and therapy to ensure achievement of normal developmental steps is needed, a psychiatrist specializing in the treatment of adolescents could be very effective.

Conclusion

For the three well-known major eating disorders, the general psychiatrist has much to contribute. First, ensuring an adequate evaluation of the physiological complications of eating disorders and utilizing this information therapeutically to promote entrance into appropriate treatment is a skill best performed by a psychiatrist. Second, providing guidance to patients utilizing various manualized self-help strategies based on CBT may increase the likelihood of recovery, especially for BN patients. Third, the information needed to use psychotropic medications appropriately for eating disorder patients is readily available. Finally, information for clinicians is available from multiple sources. The annual meeting of the American Psychiatric Association usually includes a review of current treatments for eating disorders. The websites of the Academy for Eating Disorders (6), the National Eating Disorders Association (www.nationaleatingdisorders.org), and the International Association of Eating Disorders Professionals (www.iaedp.com) have current useful data for clinicians.

Resources for Families

F.E.A.S.T. Family Guide Series. (www.feast-ed.org). This nonprofit organization includes valuable information for families in the format of brief pamphlets as well as website information.

Hill L, Dagg D, Levine M, Smolak L, Johnson S, Stotz, A, Little, N. Family Eating Disorders Manual, Guiding Families Through the Maze of Eating Disorders. Publisher: The Center for Balanced Living (a nonprofit organization). Worthington, Ohio, 2012. Kindle edition available at www.amazon.com