Basics
Description
- Eating disorders are characterized by severe disturbances in eating patterns and distortion of body image.
- Bulimia nervosa
- Repeated episodes of eating large amounts of food (binging) followed by inappropriate compensatory behaviors (purging)
- Binge-eating disorder (BED)
- Repeated episodes of binging, no purging
- Is not formally recognized as a diagnostic category; further study is necessary to determine its validity
- Anorexia nervosa
- Extreme dieting resulting in weight loss below 15% of ideal body weight
- Individuals with anorexia nervosa may also engage in binging and purging.
- Eating disorder, not otherwise specified
- Clinically significant symptoms of eating disorder, such as binge eating and severe restricting, but does not meet the full criteria for another eating disorder.
Epidemiology
- Over 90% of people with eating disorders are female.
- In the US, eating disorders are most common in Caucasian women but occur across all ethnic groups and socioeconomic classes.
Prevalence
- Lifetime prevalence of anorexia nervosa
- Lifetime prevalence of bulimia nervosa
- Prevalence rates of BED
- Vary greatly depending on sample populations
- Rates of 0.7-4% have been reported in community samples.
- Occurring more often in females than males
Risk Factors
- Low self-esteem
- Fear of losing control
- History of physical or sexual abuse
- Prior history of an eating disorder or multiple dieting attempts
- Age of onset most common in adolescence
- Female athletes (distance runners, gymnasts)
- Male athletes (body builders, wrestlers)
- Individuals with BED tend to be overweight and/or have a history of weight fluctuation.
Lifetime mortality rates for anorexia nervosa are among the highest of psychiatric disorders.
Etiology
- Genetics
- Twin and family studies lend support to heritability of eating disorders.
- The 5-HT2A receptor and brain-derived neurotrophic factor (BDNF) genes have been implicated in etiology of anorexia nervosa.
- Individuals with bulimia nervosa and BED have decreased 5-HT2A receptor binding and reduced 5-HT transporter binding, respectively.
- Cultural factors
- Eating disorders very rare in nonwestern societies.
- Psychosocial and environmental stressors, e.g., physical or sexual abuse
- Immunologic/hormonal
- Abnormalities in neuropeptides and hormones involved in satiety and hungersuch as leptin, ghrelin, and neuropeptide Y, have been implicated in eating disorders.
- These abnormalities are hypothesized to be mediated by circulating autoantibodies.
Associated Conditions
- Conditions associated with anorexia nervosa:
- Major depressive disorder
- Obsessive compulsive disorder
- Personality disorders (especially avoidant and obsessive compulsive)
- Conditions associated with bulimia nervosa:
- Major depressive disorder
- Anxiety disorders
- Substance abuse disorders
- Borderline and avoidant personality disorders
Diagnosis
Anorexia nervosa
- Characterized by self-starvation and excessive weight loss
- Symptoms include:
- Refusal to maintain appropriate body weight
- Weight <85% of appropriate weight for height and age or BMI ≤17.5 kg/m2
- Intense fear of gaining weight
- Distorted body image
- Amenorrhea in postmenarchal females
- May involve purging with or without binge eating
Bulimia nervosa
- Characterized by repeated episodes of secretive binge eating
- In contrast to patients with anorexia nervosa who may also binge, patients with bulimia nervosa do not have excessive weight loss.
- Symptoms include:
- Lack of control during binges which occur at least twice weekly for 3 months
- Eating beyond the point of comfortable fullness
- Inappropriate compensatory behaviors after binges, such as self-induced vomiting, excessive exercise, fasting, abuse of laxatives, diet pills, and/or diuretics
History
- Assess for eating disorder symptoms
- Assess for comorbid psychiatric conditions including major depressive disorder, substance abuse, obsessive compulsive disorder, and personality disorders
- Rule out medical conditions
- Signs and symptoms:
- Starvation is associated with:
- Excessive thinness, cachexia
- Bradycardia
- Hypothermia
- Anemia
- Leukopenia
- Hypotension
- Osteoporosis
- Thyroid dysfunction
- Electrolyte abnormalities
- Cognitive impairment
- Dry, scaly skin
- Lanugo (baby fine hair covering the body)
- Purging is associated with:
- Dehydration
- Erosion of tooth enamel
- Enlarged parotid glands
- Electrolyte abnormalities
Physical Exam
Physical examination to assess for signs of starvation and purging as above
Tests
- Laboratory tests to assess for signs of starvation and purging:
- CBC
- Electrolytes
- Urinalysis
- EKG
- Test for medical conditions that may produce weight loss:
- Self-report questionnaires may be helpful as screening tools for eating disorders.
- The SCOFF questionnaire (1)
- Eating Attitudes Test (2)
Differential Diagnosis
- Psychiatric disorders causing weight loss or decreased appetite:
- Major depressive disorder
- Anxiety disorders (e.g., obsessive compulsive disorder, fear of eating in public)
- Psychotic disorders (e.g., Schizophrenia)
- Body dysmorphic disorder
- Medical conditions causing weight loss:
- Hyperthyroidism, cancer, onset of diabetes mellitus, GI disorders
- Women with a history of eating disorder may relapse during pregnancy.
- Lack of increase in weight from one prenatal visit to the next during second trimester may be warning sign of eating disorder during pregnancy.
- Purging should be distinguished from hyperemesis gravidarum.
- Pregnant women with current or past eating disorders more likely to give birth to infants with low birth weight and smaller head circumferences.
- >10% mortality rate in individuals with anorexia nervosa due to suicide or medical complications such as arrhythmia.
- Weight restoration in patients with eating disorders may worsen psychiatric and medical conditions, particularly if weight gain is rapid.
Treatment
Medication
Psychotropic medications, particularly SSRIs, can be helpful in treating comorbid psychiatric symptoms (e.g., depression, obsessive compulsive disorder) and in maintaining weight gain.
- Anorexia nervosa
- Psychotropic medications are not used as the primary treatment for anorexia nervosa.
- Bulimia nervosa
- Fluoxetine: Only FDA-approved drug for treatment of bulimia (60 mg PO daily)
- Other SSRIs may also be effective.
- BED
- Fluoxetine and other SSRIs may be effective in treating BED (3)[B].
- Some preliminary studies have found that topiramate and ondansetron may help control urges to binge (4)[C].
- Atypical antipsychotics, such as olanzapine and risperidone, have been used to decrease depression and anxiety associated with eating disorder, but limited evidence in using them for weight gain in anorexia nervosa (4)[C].
- Naltrexone, an opiate antagonist, has been used with limited efficacy at high (200-300 mg PO daily) doses for eating disorders; however, these doses of naltrexone have been associated with hepatotoxicity.
Additional Treatment
General Measures
- Treatment for anorexia and bulimia nervosa may be quite lengthy (5+ years) depending on severity of illness. Treatments include:
- Individual psychotherapy
- Cognitive-behavioral
- Behavioral
- Interpersonal
- Psychoanalytic
- Psychodynamic
- Family psychotherapy
- Support groups
- With caution since patients may compete to be thinnest or most sickly in group
- Weight reduction programs, cognitive-behavioral therapy, and/or dialectical behavioral therapy may be helpful in the treatment of BED.
- Dialectical behavioral therapy helps patients improve their responses to emotional states.
Issues for Referral
- Referral for nutritional counseling and psychotherapy generally indicated; long-term.
- Follow-up care, including psychotherapy, support groups, and/or medications, may be necessary.
- Consider referral to a psychiatrist for management of comorbid conditions.
- Hospitalization may be necessary for severe malnutrition or other medical complications.
In-Patient Considerations
Initial-Stabilization
- If seriously underweight (<75% of ideal body weight) or other serious medical complications, consider hospitalization.
- Individuals with eating disorders may be resistant to treatment and deny disordered eating or being underweight.
- Family involvement and supportive environment may aid in treatment.
Discharge Criteria
- Before discharge from inpatient setting, weight and medical conditions should be stable.
- Individuals with higher discharge weights are less likely to relapse than individuals with lower discharge weights.
Ongoing Care
Follow-Up Recommendations
During weight restoration:
- Vital signs, electrolytes, GI symptoms, and cardiac function should be monitored.
- Individuals should be monitored for secretive binging and purging, and for feigning weight gain via excessive hydration.
Diet
Nutritional rehabilitation and weight restoration:
- May take place in inpatient or outpatient setting, depending on severity and individual needs
- Should be the primary focus of treatment
- Ideal target body weight should be defined
- Based on BMI or
- Weight at which individual previously had normal menses
- Healthy rate of weight gain approximately
- 2-3 lb/week in an inpatient setting
- 0.5-2 lb/week in an outpatient setting
- Create and implement plan for weight restoration. May include:
- Nutritional supplements
- Structured diet
- In extreme cases, nasogastric or parenteral feeding may be necessary.
- Rapid weight gain and decreased use of diuretics and/or laxatives may cause fluid retention, abdominal pain and, in rare cases, congestive heart failure.
- Weight gain may increase anxiety and depressive symptoms; suicidal ideation may also increase and should be monitored.
Patient Education
Activity:
- Physical activity should be limited until sufficient weight has been gained.
- Emphasize that physical activity should be to maintain fitness and not to burn calories.
- Individuals who are physically restless and continually fidget may require higher caloric intake to stabilize weight.
Prognosis
A number of factors influence treatment outcome:
- Poorer prognosis is associated with:
- Failure to respond to previous treatment
- Frequent vomiting
- Poor quality of family relationships
- Comorbid psychiatric illness
- Better prognosis is associated with:
- Early detection
- Higher initial body weight
- Younger individuals
References
1 The SCOFF questionnaire: Assessment of a new screening tool for eating disorders. BMJ. 1999;319(7223):1467-1468.2Garner DM, Garfinkel PE. The eating attitudes test: An index of the symptoms of anreoxia nervosa. Psychological Medicine. 1979;9:273-279. [View Abstract]3Husted DS, Shapira NA. Binge-eating disorder and new pharmacologic treatments. Primary Psychiatry. 2005;12(4):46-51.4McKnight RF, Park RJ. Atypical antipsychotics and anorexia nervosa: A review. Eur Eat Disord Rev. 2010;18(1):10-21. [View Abstract]
Additional Reading
1Judge BS, Eisenga BH. Disorders of fuel metabolism: Medical complications associated with starvation, eating disorders, dietary fads, and supplements. Emerg Med Clin North Am. 2005;23:789-813. [View Abstract]2Steinhausen HC. Outcome of eating disorders. Child Adolesc Psychiatr Clin N Am. 2009;18(1):225-242. [View Abstract]3Yager J, Anderson A, Devlin M. Practice guideline for the treatment of patients with eating disorders. In: Practice guidelines for the treatment of psychiatric disorders compendium 2006, 3rd ed. Washington, DC: American Psychiatric Association, 2006.
Codes
ICD9
- 307.50 Eating disorder, unspecified
- 307.51 Bulimia nervosa
- 307.1 Anorexia nervosa
- 307.59 Other disorders of eating
- 300.7 Hypochondriasis
ICD10
- F50.00 Anorexia nervosa, unspecified
- F50.2 Bulimia nervosa
- F50.9 Eating disorder, unspecified
- F50.8 Other eating disorders
- F45.22 Body dysmorphic disorder
SNOMED
- 72366004 eating disorder (disorder)
- 78004001 bulimia nervosa (disorder)
- 56882008 anorexia nervosa (disorder)
- 63393005 anorexia nervosa, binge-eating purging type (disorder)
- 439960005 binge eating disorder (disorder)
- 77675002 anorexia nervosa, restricting type (disorder)
- 59645001 bulimia nervosa, nonpurging type (disorder)
- 32721004 bulimia nervosa, purging type (disorder)
- 83482000 body dysmorphic disorder (disorder)
Clinical Pearls
- Eating disorders may have serious medical complications which should be monitored during treatment and weight restoration.
- Early detection is associated with a better prognosis.
- Psychotherapy is mainstay of treatment, and SSRIs appear to be helpful in the treatment of bulimia nervosa and binge-eating disorder.