Anorexia Nervosa

Primer

Anorexia nervosa is an eating disorder characterized by a fear of gaining weight, strong desire to be thin, and food restriction, which results in low weight. It is the highest mortality psychiatric illness with a mortality rate of 10%.

Subtypes

Individuals with anorexia nervosa, binge-eating/purging type can binge eat and also purge through self-induced vomiting or the misuse of laxatives, diuretics, or enemas. However, some individuals will not binge eat but will regularly purge after eating small amounts of food. Crossover between the subtypes over the course of the disorder is not uncommon; therefore, subtype description should be used to describe current symptoms rather than longitudinal course.

Diagnostic Criteria

Criterion A

Restriction of energy intake relative to requirements, leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health.

Significantly low weight is defined as a weight that is less than minimally normal or, for children and adolescents, less than that minimally expected.
Criterion B

Intense fear of gaining weight or of becoming fat, or persistent behavior that interferes with weight gain, even though at a significantly low weight.

Criterion C

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

Specifiers

Specifiers

  • Restricting type: During the last 3 months, the individual has not engaged in recurrent episodes of binge eating or purging behavior (i.e., self-induced vomiting or the mis use of laxatives, diuretics, or enemas). This subtype describes presentations in which weight loss is accomplished primarily through dieting, fasting, and/or excessive exercise.
  • Binge-eating/purging type: During the last 3 months, the individual has engaged in recurrent episodes of binge eating or purging behavior (i.e., self-induced vomiting or the misuse of laxatives, diuretics, or enemas).
  • In partial remission: After full criteria for anorexia nervosa were previously met. Criterion A (low body weight) has not been met for a sustained period, but either Criterion B (intense fear of gaining weight or becoming fat or behavior that interferes with weight gain) or Criterion C (disturbances in self-perception of weight and shape) is still met.
  • In full remission: After full criteria for anorexia nervosa were previously met, none of the criteria have been met for a sustained period of time.

Severity Specifier

The minimum level of severity is based, for adults, on current body mass index (BMI) (see below) or, for children and adolescents, on BMI percentile. The ranges below are derived from World Health Organization categories for thinness in adults; for children and adolescents, corresponding BMI percentiles should be used. The level of severity may be in creased to reflect clinical symptoms, the degree of functional disability, and the need for supervision.

  • Mild: BMI > 17kg/m2
  • Moderate: BMI = 16-16.99 kg/m2
  • Severe: BMI = 15-15.99 kg/m2
  • Extreme: BMI < 15 kg/m2

Screening

The SCOFF Questionaire

The SCOFF is a simple 5-question screening questionnaire for anorexia and validated in specialist and primary care setting (sensitivity of 100% and specificity of 90%).[1] Though not diagnostic, a score of 2 or more positive answers should raise your index of suspicion of a case, highlighting need for more detailed history.
  1. S: Do you ever make yourself sick because you feel uncomfortably full?
  2. C: Do you worry you have lost control over how much you eat?
  3. O: Have you recently lost more than one stone [14 pounds/6.4kg] in a 3 month period?
  4. F: Do you believe yourself to be fat when others say you are too thin?
  5. F: Would you say that food dominates your life?

Symptoms

  • Weight loss
  • Hyperactivity
  • Bradycardia
  • Hypotension
  • Brittle hair and nails
  • Dry or yellow skin
  • Cyanotic hands and feet
  • Edema
  • Amenorrhea
  • Sleep disturbance
  • Weakness, fatigue
  • Dizziness
  • Constipation
  • Non-focal abdominal pain
  • Polyuria
  • Cold intolerance

Investigations

  • Elevated serum amylase[2]

Treatment

Medical

Medication

Psychological

Once weight-gain has restarted, various forms of psychotherapy have been found to be effective for treatment of anorexia, including:[3][4]

  • Individual therapy (CBT, IPT, and psychodynamic approaches)
  • Group therapy (CBT, IPT, and psychodynamic approaches)
  • Family and couple’s self-help, online resources, 12 step programs

Resources

For Patients
For Providers
Articles
Research

References

1) http://cedd.org.au/wordpress/wp-content/uploads/2014/09/The-SCOFF-Questionnaire-SCOFF.pdf
2) Wolfe, B. E., Jimerson, D. C., Smith, A., & Keel, P. K. (2011). Serum amylase in bulimia nervosa and purging disorder: Differentiating the association with binge eating versus purging behavior. Physiology & behavior, 104(5), 684-686.
3) Yager, Joel, et al. Practice guideline for the treatment of patients with eating disorders. American Psychiatric Association, 2006. Third Edition
4) Guideline Watch for the Practice Guideline for the Treatment of Patients With Eating Disorders 11