Anorexia Nervosa (AN)
Detailed Diagnostic Criteria
Detailed diagnostic criteria are taken from the Diagnostic Statistical Manual, 4th edn. (DSM-IV).
- 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)
- Intense fear of gaining weight or becoming fat, even though underweight.
- 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.
- In females, amenorrhea (absence of more than three menstrual periods)
- 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