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Anorexia Nervosa, Bulimia, and Eating Disorders: Diagnosis and Treatment

I. Eating Disorders and Their Subtypes: Diagnostic Criteria

A. Anorexia nervosa

Diagnostic criteria for anorexia nervosa

A. Refusal to maintain body weight at or above a minimally normal weight for age and height (eg, weight loss leading to maintenance of body weight less than 85% of that expected; or failure to make expected weight gain during period of growth, leading to body weight less than 85% of that expected).

B. Intense fear of gaining weight or becoming fat, even though underweight.

C. Disturbance in the way in which one's body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or denial of the seriousness of the current low body weight.

D. In postmenarcheal females, amenorrhea, ie, the absence of at least three consecutive menstrual cycles. (A woman is considered to have amenorrhea if her periods occur only following hormone, eg, estrogen, administration.)

Specify type:

Restricting Type: during the current episode of Anorexia Nervosa, the person has not regularly engaged in binge-eating or purging behavior (ie, self-induced vomiting or the misuse of laxatives, diuretics, or enemas)

Binge-Eating/Purging Type: during the current episode of Anorexia Nervosa, the person has regularly engaged in binge-eating or purging behavior (ie, self-induced vomiting of the misuse of laxatives, diuretics, or enemas)

Diagnostic criteria for bulimia nervosa

A. Recurrent episodes of binge eating. An episode of binge eating is characterized by both of the following:

(1) eating, in discrete period of time (eg, within any 2-hour period), an amount of food that is definitely larger than most people would eat during similar period of time and under similar circumstances

(2) a sense of lack of control over eating during the episode (eg, a feeling that one cannot stop eating or control what or how much one is eating)

B. Recurrent inappropriate compensatory behavior in order to prevent weight gain, such as self-induced vomiting; misuse of laxatives, diuretics, enemas, or other medications; fasting; or excessive exercise.

C. The binge eating and inappropriate compensatory behaviors both occur, on average, at least twice a week for 3 months.

D. Self-evaluation is unduly influenced by body shape and weight.

E. The disturbance does not occur exclusively during episodes of Anorexia Nervosa.

Specify types:

Purging Type: during the current episode of Bulimia Nervosa, the person has regularly engaged in self-induced vomiting or the misuse of laxatives, diuretics, or enemas

Nonpurging Type: during the current episode of Bulimia Nervosa, the person has used other inappropriate compensatory behaviors, such as fasting or excessive exercise, but has not regularly engaged in self-induced vomiting, or misuse of laxatives, diuretics, or enemas

(American Psychiatric Association, 1994)

Research criteria for binge-eating disorder.

A. Recurrent episodes of binge eating. An episode of binge eating is characterized by both of the following:

(1) eating, in a discrete period of time (eg, within any 2-hour period), an amount of food that is definitely larger than most people would eat in a similar period of time under similar circumstances

(2) a sense of lack of control over eating during the episode (eg, a feeling that one cannot stop eating or control what or how much one is eating)

B. The binge-eating episodes are associated with three (or more) of the following:

(1) eating much more rapidly than normal

(2) eating until feeling uncomfortably full

(3) eating large mounts of food when not feeling physically hungry

(4) eating alone because of being embarrassed by how much one is eating

(5) feeling disgusted with oneself, depressed, or very guilty after overeating

C. Marked distress regarding binge eating is present.

D. The binge eating occurs, on average, at least two days a week for 6 months.

E. The binge eating is not associated with the regular use of inappropriate compensatory behaviors (eg, purging, fasting, excessive exercise) and does not occur exclusively during the course of Anorexia Nervosa or Bulimia Nervosa.

D. Atypical eating disorders (EDNOS)

1. Eating disorder not otherwise specified includes disordered eating that is atypical (eg, chewing and spitting) or subsyndromal (eg, bingeing and purging weekly)

2. Many of those with partial syndrome disorders develop full-syndrome disorders and vice versa

II. Epidemiology

A. Prevalence of Anorexia and Bulimia

  Anorexia Bulimia
Point prevalence (among young females) 0.28% 1%
Lifetime prevalence (among young females) -- up to 4.2%

1. Difficulty of case detection complicates estimates

2. Partial syndrome disorders may be twice as prevalent as full-syndrome disorders

3. Disordered eating behaviors and attitudes occur in up to 15% college-age women

4. 85-90% of cases occur in females

5. Eating disorders are far more prevalent in Westernized or industrialized societies, yet may be more common or increasingly common among certain ethnic minority women

6. The relationship between eating disorders and socioeconomic status is unclear

B. Prevalence of BED

Population Prevalence of BED
College student samples 2.6%
Weight control programs 29%

1. BED is the most common eating disorder and the most common eating disorder among men

2. 40% of cases occur in men and 60% occur in females

III. Etiology

A. Sociocultural factors

1. Cultural pressures to be slim promote dieting, sometimes precipitating an eating disorder; media appears to play a role in routinizing and disseminating extremely thin body types

2. Culturally conditioned ideas and values about identity, embodiment, and the desirability of remaking or perfecting oneself no doubt permit eating disorders to develop in certain cultures

3. Conflicts generated by cultural transition (eg, gender role expectations, participation in global economy) may play a role

B. Psychological factors

1. Disordered eating often serves to self-soothe or to manage intolerable affect--sometimes replacing more self-destructive defenses such as substance abuse

2.Feelings of self-efficacy are often achieved by self-restraint/thinness

3. An individual with an eating disorder is often identified as the "troubled" individual in a disturbed family system

4. Symptoms which originally may serve as a coping mechanism often eventually are experienced as distressing

C. Biological factors

1. Serotonergic dysregulation may play a role in both bulimia and anorexia, although cause and effect have not been determined

2. Genetic basis of both anorexia and bulimia is suggested by twin studies

IV. Course

A. Eating disorders: Course and outcome

B. Onset of anorexia and bulimia is typically in the teens; anorexia has an earlier age of onset than bulimia

C. Early age of onset, high education or social status, and a short interval between onset of symptoms and treatment are favorable prognostic indicators for anorexia

D. Limited data are available on the course of BED; onset is typically in the late adolescence/early 20s; one study found that for treated females, 57.4% had good outcome, 35.3% had intermediate outcome, 5.9% had poor outcome and 1.4% died (N=68) (Fichter et al 2006)

V. Evaluation for the Eating Disorders Is Optimally Managed by a Multidisciplinary Team

A. Psychological evaluation should include:

1. Assessment for comorbid mood, anxiety, substance abuse, and personality disorders

a. Major depression, dysthymia, obsessive-compulsive disorder are associated with anorexia

b. Depression, bipolar disorder, substance abuse, anxiety disorders, and personality disorders are associated with bulimia

c. Depression, panic disorder, substance abuse, and personality disorders are associated with BED

2. A weight and dieting history as well as an inventory of compensatory behaviors, including self-induced vomiting (with or without ipecac), laxatives, diet pills, diuretics, enemas, exercise, restrictive pattern eating, medication or substance abuse (eg, Ritalin, insulin, caffeine, cocaine).

3. Assessment of psychosocial precipitants to (proximate and distal) and processes underlying symptoms; clinicians should be sensitive to the possibility of trauma and early losses in this population

4. Assessment of need for family education and/or intervention

5. Assessment of suicide risk

B. Nutritional evaluation should include:

1. Assessment of caloric intake and caloric/other nutrient needs; assessment of energy expenditure

2. Assessment of nutritional status (generally as a percentage of "ideal body weight" (IBW) or as body mass index (BMI)

Estimating percentage ideal body weight 0BW):

IBW = 100 lbs + 5 lbs/inch above 5 ft 10% (for females)

Note that there may be some individual variation with respect to healthy body weight.

Calculating Body Mass Index (BMI):

BMI = Weight (kg)/[Height (m)]2

C. Medical evaluation should include assessment for any associated potential medical complications with special attention to risk of: high or low weight, vital signs changes, electrolyte abnormalities, disturbance of reproductive function, and bone demineralization:

1. Determination of significance of weight is best done by calculating BMI

BMI Weight category*
<17.5 Anorexic range
>17.5- 19 or 20 Underweight
20-25 Normal weight
25-30 Overweight
>30 Obese
>40 Morbidly obese

* Reflects weight categories appropriate for adults

Determination of clinical significance of weight can also be made by calculating an individual's weight as a percentage of ideal body weight (IBW): [wt/IBW] x 100= % IBW

% IBW Clinical significance
60% Risk of mortality may increase
75% Generally requires inpatient care
<85% Anorexic range
90-110% Normal weight range
>120% Obese

(Note that visual approximations of appropriateness of weight are often highly inaccurate since individuals may disguise their weight with baggy, loose, or layered clothing.)

2. Individuals with anorexia can present with hypotension, bradycardia, and hypothermia. Those with bulimia can also present with hypotension and bradycardia; alternatively, tachycardia may reflect dehydration secondary to purging. Obese individuals with BED may present with hypertension.

3. Electrolyte disturbances often occur in the presence of purging; both metabolic alkalosis and acidosis are possible. Hypokalemia may be seen with many of the modalities of purging.

4. Menstrual function should be assessed in women. Eating disorders can cause delayed puberty and infertility as well as complicate the course of a pregnancy. Amenorrhea associated with anorexia nervosa is most often due to decreased gonadotropin releasing hormone pulsatility, but other causes (eg, pregnancy) should be excluded.

5. 50% of anorexics have significant osteoporosis, some - but not all - of which may reverse with weight gain. Anorexia during adolescence can cause short-stature or peak bone mass reduction. Women with anorexia nervosa should have a dual-energy x-ray absorptiometry (DEXA) evaluation of lumbar spine density to assess bone loss.

6. Other potential complications of low weight, overweight, poor nutrition, or purging should be evaluated and addressed.

a. Assessment of individuals with anorexia nervosa should include examination for: dry skin, yellow skin, lanugo, hair loss, acrocyanosis, mitral valve prolapse, arrhythmia, decreased bowel sounds, and peripheral neuropathy.

b. Assessment of individuals with bulimia nervosa or with bingeing/purging behaviors should include examination for: parotid gland enlargement, submandibular adenopathy, dental caries, hand abrasions (Russell's sign), decreased or increased bowel sounds, and rectal prolapse.

7. Laboratory analysis should include initial and periodic assessment of serum electrolytes. Patients with anorexia nervosa should have a serum glucose to exclude hypoglycemia and a complete blood count to exclude leukopenia, neutropenia, anemia, and thrombocytopenia. Patients with electrolyte disturbances, symptomatic arrhythmias, or for whom psychopharmacologic intervention is planned should have an electrocardiogram to evaluate the QT interval and any other abnormalities.

V. Treatment

A. Engagement of an individual in treatment:

1. Typically, there is a lag time of several years between illness and treatment for several reasons

a. Symptoms may not be recognized as problematic by the patient or her family

b. Symptoms may be experienced as shameful

c. There may be dependence upon symptoms for self-soothing or other purposes and thus an unwillingness to give them up

2. Empathic, non-judgmental questioning about symptoms is useful if illness is suspected; gentle confrontation may be necessary

a. Educate patient about potential medical complications

b. Explain a need for team treatment to patient

c. Explain that initial goals may center on medical stabilization and identifying alternative coping mechanisms rather than necessarily a simple eradication of symptoms

B. A multidisciplinary team approach is optimal for most patients; treatment minimally must address safety from medical complications and self-harm. After safety is addressed, treatment is targeted toward reestablishment of healthful patterns of eating and self-regard and the psychological underpinnings of the symptoms. The treatment team generally will include:

1. Psychotherapist + psychopharmacologist (possibly also family therapist and/or group therapist)

2. Primary care clinician

3. Nutritionist

C. Psychotherapeutic treatments will often establish a weight or other behavioral contract with the patient to specify parameters at which treatment needs intensification (ie, transfer to inpatient or partial hospitalization care). Patients who are significantly underweight may not be able to engage in insight-oriented work because of cognitive impairment. Specific treatment modalities include:

1. Cognitive behavioral therapy (CBT) is effective for bulimia (and shows promise for BED; less is known about its efficacy in anorexia) with mean reduction of binge eating 73-93% and purging 77-94%; mean remission of binge eating 51-71% and purging 36-36%.

2. Interpersonal therapy (IPT) is equally effective as CBT in treatment of bulimia; it is also effective in treatment of BED

3. Psychodynamic psychotherapy is less well studied, but may be a useful approach in any of the eating disorders depending on the interpersonal difficulties/comorbid disorders that the patient presents with.

4. Group therapy is useful generally as an adjunctive therapy in anorexia or bulimia; group CBT or IPT is effective in treatment of BED

5. Family therapy is useful adjunct for adolescents with anorexia or bulimia

D. Pharmacotherapy is generally only offered in the context of psychotherapy

1. Pharmacotherapy in anorexia is highly individualized, depending on comorbid disorders and stage of illness, among other things.

a. There is some evidence that fluoxetine may be helpful in stabilizing weight-recovered anorexics

b. Some agents have been demonstrated helpful in weight-restoration (eg, cyproheptadine, zinc) but are not routinely clinically useful

c. Other agents may be useful (ie, antidepressants, anxiolytics) to treat associated symptoms, but careful assessment of medical status is necessary to determine whether an individual can tolerate the medication d. Cisapride may diminish unpleasant sensations associated with refeeding

2. A variety of antidepressant medications have been moderately effective in treating bulimia with an overall decrease in binge frequency averaging 56% and similar rates of decrease for self-induced vomiting; improvement should be seen in 1-3 weeks and response is not related to presence of comorbid depression. It is unclear whether any one agent is superior since there are few data comparing one agent against others

a. Agents are generally chosen based on their side-effect profiles; SSRIs are generally well-tolerated in this population. More than one trial of agent may be optimal in selecting the most effective agent.

b. Fluoxetine is the only FDA approved treatment for bulimia with 60 mg being superior to 20 mg daily.

c. Bupropion should be avoided among individuals with eating disorders because of the risk of seizure.

3. Pharmacotherapy has been less well-studied in BED

a. Fluvoxamine is the only currently available medication that has been found effective in the treatment of BED

b. Desipramine has been found effective in non-purging bulimia but not studied in BED


Summary of Agents Available in the US Studied in Controlled Clinical Trials in Adults Demonstrating Significant Efficacy Compared with Placebo
Anorexia Nervosa Bulimia Nervosa Binge-Eating Disorder
Fluoxetine (in weight-recovered individuals only)

Cyproheptadine (in restricting type anorexia only)










Naltrexone (200-300 mg/d)*



*Either relatively contraindicated or not recommended as a first line agent because of potential serious adverse effects.

** Studied in non-purging bulimic individuals but not BED

(Adapted from Becker, A.E., P. Hamburg, and D.B. Hcrzog. 2006. The Role of Psychopharmacologic Management in the Treatment of Eating Disorders. In: Psychiatric Clinics of North America: Annual of Drug Therapy, Dunner, D. and Rosenbaum, J., eds.. P. 45, with .)

E. Medical Treatment. Unless there is a psychiatric emergency, initial goals of treatment for patients with eating disorders often include medical and nutritional stabilization

1. Weight restoration is the primary medical goal for anorexia nervosa; generally this requires active management; preferred means is with educational and behavioral treatment; enteral and total parenteral feeding are reserved for only severe cases of anorexia and require close medical supervision because of the associated risk of a "refeeding syndrome"; weight loss may be indicated in some patients with BED, but should be discouraged in bulimia nervosa

2. Weight, vital signs, and often electrolytes, need to be routinely monitored; correction of hypokalemia and other electrolyte disturbances should be addressed promptly

3. Patients with anorexia nervosa generally will need calcium 1000-1500 mg/day with a vitamin D containing multivitamin

4. Estrogen replacement therapy may symptomatically alleviate estrogen deficiency symptoms but has not been demonstrated effective in treating osteopenia in women with anorexia nervosa

5. Patients with chronic vomiting should have regular dental care

6. Other potential medical complications of purging behaviors and abnormal weight should be periodically assessed and addressed

F. Inpatient care is indicated in the setting of serious medical or psychiatric risk such as described below:

1. Rapid and significant weight loss or weight <75% IBW

2. Imminent risk of medical danger due to malnutrition, dehydration, electrolyte abnormalities, Ipecac use, or organ failure

3. Severe or escalating symptoms

4. Psychiatric emergency

5. Arrested growth or development

6. Failure of outpatient management