Table 1.
Eating disorder-related phenotype descriptions.
| Phenotype | Definitions |
|---|---|
| Anorexia nervosa (AN)a | Diagnostic criteria included: 1. BMI less than minimally expected 2. Intense fear of gaining weight 3. Weight or shape disturbance, undue influence of weight or shape, or denial of the seriousness of the disorder |
| AN with binge-eatingb | Individuals with AN who also engaged in binge eating episodes, defined as eating a large amount of food in a short period of time while having a sense of loss of control over the eating episode. The binge eating episodes must have occurred at least twice a week for three months. |
| AN without binge-eatingb | Individuals with AN who did not engage in binge eating episodes. |
| Bulimia nervosa (BN)c factor | Derived from a factor analysis that included the following items: 1. Reporting self-induced vomiting to control body weight 2. Reporting suffering from or being treated for binge eating 3. Reporting suffering from or being treated for bulimia |
Note:
A fourth diagnostic criterion for AN includes amenorrhea. However, amenorrhea was excluded as a required criterion for cases in the Psychiatric Genomics Consortium datasets since it is no longer a diagnostic criterion in the DSM-5.
The DSM and ICD include two subtypes of anorexia nervosa (AN)—a binge-eating/purging subtype and a restricting subtype. Although it would have been ideal to examine differences between the AN binge-eating/purging subtype and AN restricting subtype, this was not possible with current Psychiatric Genomics Consortium data. However, there was sufficient information about presence or absence of binge eating, which resulted in creating the AN with binge-eating and AN without binge-eating subtypes.
Bulimia nervosa is defined as: 1) recurrent episodes of binge eating; 2) recurrent inappropriate compensatory behaviors (e.g., self-induced vomiting, laxative use) to prevent weight gain; 3) the binge eating and inappropriate compensatory behaviors occurring an average of twice a week for three months; 4) having undue influence of body weight and shape; and 5) disturbance not occurring during AN.