The subjects were from 17 countries, and all of them had European ancestry.
This time, the researchers identified eight genetic loci linked to the disorder, although Bulik says there are likely hundreds.
“Right now, we have no medications effective in treatment of this illness,” she says.
“We’re starting at zero.” Attia agrees that learning more about the genetics involved is a helpful first step toward therapies.
Nevertheless, the study’s conclusions increase our understanding of genetic contributors to anorexia.
Pharmacogeneticists may be able to use them as a starting point to develop new treatments, Bulik says.
Some of these locations have been linked to metabolic problems—suggesting the causes of anorexia may not be purely psychological.
Anorexia nervosa, as it is officially known, is an eating disorder primarily associated with an extremely low body mass index (BMI), usually accompanied by an aversion to eating and a distorted body image.
One of the disorder’s most insidious features is that many patients are able to restore their body to a normal weight but have trouble keeping the pounds on. Yet somehow [people with anorexia] have this capacity to get down to a dangerously low weight and stay there,” says study co-author Cynthia Bulik, a professor of eating disorders at the University of North Carolina at Chapel Hill and the Karolinska Institute in Sweden.
“It has been explained psychologically—but it would take such an enormous amount of willpower to do that.” In treatment centers, patients can be nourished to a healthy BMI, Bulik says, but “we send them back out, and their weight just starts dropping like a stone again.” The trend seems almost the inverse of obesity, in which patients can lose weight quite easily, but it often returns.