Anorexia Nervosa (AN)

Detailed Diagnostic Criteria

Detailed diagnostic criteria are taken from the Diagnostic Statistical Manual, 4th edn. (DSM-IV).

  1. Refusal to maintain body weight at or above a minimally normal weight for age and height (e.g., weight loss leading to body weight less than 85% of that expected)
  2. Intense fear of gaining weight or becoming fat, even though underweight.
  3. Disturbance in the way in which one's body weight, size, or shape is experienced (i.e. body image disturbance); denial of the seriousness of the current low body weight.
  4. In females, amenorrhea (absence of more than three menstrual periods)
  5. Subtypes:
    • Restricting Type: During the current episode of Anorexia Nervosa, the person has not regularly engaged in binge-eating or purging behavior (i.e., 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 (i.e., self-induced vomiting or the misuse of laxatives, diuretics, or enemas). 

Prevalence of Eating Disorders

 According to Keel (2005) and Wilson, Grilo & Vitousek (2007), the prevalence of eating disorders is as follows: 

  • The female-to-male ratio is 10:1
  • The percentage of women who have had anorexia at some point in their lifetime (lifetime prevalence) is 0.5%

Typical Course of Eating Disorders

Keel (2005), Steinhausen (2002) and Wilson, Grilo & Vitousek (2007) describe the typical onset and course of eating disorders:

  • Onset: usually early to late adolescence
  • Approximately 50% recover (an absence of all clinical symptoms)
  • 33% improve but remain symptomatic
  • 20% the illness becomes chronic and remitting
  • 5% of those diagnosed eventually die – this is the highest mortality of any psychiatric disorder.
    • The leading cause of death is medical complications.
    • The second most common cause is suicide.
  • 51% of patients hospitalized eventually require a second hospitalization
  • 10-50% of individuals with anorexia cross over to bulimia