Halmi K A, Casper R C, Eckert E D, Goldberg S C, Davis J M
Psychiatry Res. 1979 Oct;1(2):209-15. doi: 10.1016/0165-1781(79)90063-5.
The relationship between age of onset of anorexia nervosa and a variety of personal characteristics was examined in 105 patients. Age of onset of anorexia nervosa had a bimodal distribution, with peaks at 14 1/2 and 18 years. The patients whose onset of illness occurred at the later age tended to have a greater weight loss during their illness, more "underweight problems" before the onset of illness, less of the typical anorectic behaviors and attitudes, greater body disparagement, more symptoms of depression, and a greater number of previous hospitalizations. These associations suggest that an older age of onset of anorexia nervosa might predict a poor outcome.