"Consequently, many patients with the disorder remain ill for years or eventually die from the disease, which has the highest death rate of any psychiatric disorder." A better understanding of the underlying neurobiology – how behavior is coded in the brain and contributes to anorexia —is likely to result in more effective treatments, according to the researchers.Childhood personality and temperament may increase an individual's vulnerability to developing anorexia.“There’s no question that this is an extremely important study and is aiming to take state-of-the-art methods and use them to examine the genetic risk factors that may be at the base of the challenging disorder of anorexia nervosa,” says Evelyn Attia, a professor of psychiatry at Columbia University Irving Medical Center, who was not involved in the work.
To look deeper, Bulik says she and her team plan to increase the size of their study sample and to diversify it by including more people of African and Asian ancestry.
Although their latest paper had a large number of subjects, it was still relatively small by the standards of such genetic-association studies.
Some of the eight were associated with psychiatric illnesses—but others were associated with metabolic traits, even after the researchers controlled for BMI.
This result suggests the risk of developing anorexia may be linked to metabolic factors, the researchers report in the study, which was published in July in .
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.It affects about 1 to 4 percent of women and 0.3 percent of men.Previous studies in twins suggest it has a 50 to 60 percent heritability, meaning 50 to 60 percent of the variability of the traits associated with anorexia can be explained by genetic differences among people, with the remainder linked to the environment or other influences.And there are many other eating disorders besides anorexia whose genetic involvement has yet to be explored. “For now, this [research] actually gives an explanatory model to a lot of patients and families who have just been perplexed by this illness for a long time,” Bulik says.New imaging technology provides insight into abnormalities in the brain circuitry of patients with anorexia nervosa (commonly known as anorexia) that may contribute to the puzzling symptoms found in people with the eating disorder.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.She went back in 19—before and after television became widespread in the country—and noted a striking increase in the number of girls who reported “purging” themselves to look more like women they saw on TV.Becker says science still has an incomplete understanding of how social norms, food insecurity and social determinants of poor health affect vulnerability to the disorder.“We don't know what the mechanism is here yet,” she says.“It’s just something that we've seen clinically for years but haven’t thought about as potentially [involving] opposite ends of the same underlying process.” Bulik and her colleagues published a study in 2017 that analyzed the genomes of about 3,500 people with anorexia.