This explans how anorexia is linked to a pleasure-regulating brain chemical.

Women who suffer from anorexia have increased chemical activity in a part of the brain that controls reward and reinforcement, something that may explain why they are driven to lose weight but don’t get any pleasure from it, according to a new study. Researchers used brain-imaging technology on 10 women who had recovered from anorexia and 12 healthy women. In the anorexic women, they found overactivity by dopamine receptors in a part of the brain known as the basal ganglia. Dopamine is a brain chemical that is associated with regulating pleasure. “The take-home message is dopamine in this area may be very important in how we respond to stimuli, how we view positive and negative reinforcement,” said Dr. Walter Kaye, a psychiatry professor at the University of Pittsburgh Medical Center and one of the researchers involved in the study. Dr. Guido Frank, a child psychiatry fellow at the University of California at San Diego and also a leader of the study, said the hope is that the research can lead to the development of drugs to treat anorexia. “It’s very, very hard to treat. They recognize it’s wrong, but they still don’t eat,” Frank said. The research was reported this month online in the journal Biological Psychiatry. About 1 percent of American women suffer from anorexia, a disease than can also affect men. It has the highest death rate of any psychiatric illness, Kaye said. Women suffering from anorexia have obsessional personalities, avoid harm and prefer routine, said Dr. Douglas Bunnell, past president of the National Eating Disorders Association and clinical director of the Renfrew Center of Connecticut. These women tend to resist therapy and have a distorted perception of themselves, he said. Although only a small number of women get anorexia in its purest form, there are many more people who suffer from some form of an eating disorder, Bunnell said. Making the connection between anorexia and what’s happening in the brain is important for understanding and treating eating disorders, he said.