Kate Moss worshippers and other stereotyped sufferers of anorexia nervosa got some of the stigma of their disorder lifted recently, thanks to research done by Wade Berrettini, Ph.D., director of Penn's Center for Neurobiology and Behavior.

It turns out that anorexia -- an eating disorder in which victims starve themselves, sometimes to death -- might be traced to biological causes, rather than purely societal and cultural pressures.

"There's an enormous emphasis on thinness in society's image of female beauty, and most people think a woman's risk of developing anorexia nervosa derives solely from that fact," Berrettini said. "But studies of twins and families suggest that about half the risk of developing this eating disorder is inherited."

Experts say women suffer from eating disorders such as anorexia nervosa and bulimia 10 times more than men. About 20 percent of such cases are fatal, from suicides to cardiac arrest victims, according to Chris Berrettini, Wade Berrettini's wife and clinical coordinator for the anorexia studies.

"There's a lot of guilt associated with the disorders," Chris Berrettini said. She hopes the findings will encourage more sufferers to seek help, and eventually determine a pharmacological treatment.

In his recently published review of studies of anorexic twins, Berrettini found that both members of a pair of identical twin sisters were substantially more likely to suffer from anorexia than were both members of a pair of fraternal twin sisters.

Also, immediate family members of anorexic women were 10 times more likely to contract the disorder than were members of the general population.

"There is not a single government-approved medicine to treat anorexia," Berrettini said. "It's our hope that if we can find susceptibility genes, we will then be able to develop better treatments for the disorder."