Rate of anorexia may be underestimated

By Joene Hendry

NEW YORK (Reuters Health) - The occurrence rate of anorexia among young women seems to be substantially underestimated, study findings suggest, and at the same time many affected women recover without treatment.

An assessment of data from a study of Finnish female twins indicates that anorexia nervosa occurs at a rate equivalent to 270 cases per 100,000 people per year among women aged 15 to 19 years, report Dr. Anna Keski-Rahkonen, at the University of Helsinki, and colleagues.

Previous reports pegged incidence rates at 136 and 109 per 100,000 person-years in the United States and the Netherlands, respectively. However, these estimates were based on cases that were identified and treated.

Up to half of cases go unrecognized and untreated, Keski-Rahkonen told Reuters Health. "The number of unrecognized and untreated women with anorexia is very similar in any industrialized western country," she added.

To better understand the long-term impact of the eating disorder, the researchers conducted telephone interviews with 292 Finnish twins with symptoms of anorexia as well as with 134 of their symptom-free co-twins and 210 randomly selected "controls" who screened negative for the disorder.

These interviews showed that two-thirds of those with anorexia recovered within 5 years, to the point of being as physically healthy as their unaffected co-twins and the control group, Keski-Rahkonen and colleagues report in American Journal of Psychiatry. The psychological impact of the illness also receded steadily on all measures except body dissatisfaction and psychosomatic symptoms, the researchers found.

Factors that helped undiagnosed women regain control of their lives and recover from anorexia, Keski-Rahkonen said, included not wanting to see a psychiatrist, an aversion to lengthy hospital stays or long treatments, new interests or friends, or moves to a new school or city.

Still, early detection and effective treatments are important. Even though "seven out of ten women will eventually recover," Keski-Rahkonen said, "we can't currently predict the course of the illness ... who will recover spontaneously, who will need lots of intensive treatment, and who will die from anorexia."

SOURCE: American Journal of Psychiatry, August 2007.