Researchers attempting to identify genetic links to anorexia nervosa need volunteers for the first government-funded genetic study of the eating disorder in the United States.
If it is successful,the study could eventually lead to new treatments for the disorder,which is now treated with behavioral modification.
The National Institutes of Health needs 400 families that have two or more relatives with anorexia to participate in the study. The family members with the disorder will participate in the study.
“This is a very important and major medical and psychiatric problem,” said Dr. Walter Kaye,a professor of psychiatry at the University of Pittsburgh Medical Center. “Anorexia nervosa has the highest death rate of any psychiatric illness.”
According to the National Institute of Mental Health,between 0.5 percent and 3.7 percent of females will suffer from anorexia nervosa in their lifetimes. Between 1.1 percent and 4.2 percent of females will suffer from bulimia. Although men get anorexia much less often than women,both men and women will be accepted for the study.
Anorexics starve themselves,and bulimics binge and purge. Some people with eating disorders go back and forth. Most people with eating disorders develop them in adolescence.
Kaye is the principal investigator for the study's Pittsburgh site. There are seven sites in the United States and one each in Germany,England and Canada. The NIMH is running the $10 million study.
Kaye said about 50 families have been recruited. He said he expects the study to gain momentum over time,but he also said it can be difficult to recruit participants because the criteria are narrow.
“We just want certain symptoms and not others,” Kaye said. “Theoretically,this might make it easier to find the genes for those specific symptoms.”
Families with at least two biologically related individuals who have or had anorexia are eligible for the study as long as they meet other guidelines.
The study is looking for first-,second- and third-degree relatives. For example,that includes siblings,except for identical twins,first cousins or aunt-niece pairs. Parent-child pairs are not accepted.
Both individuals must have been diagnosed with anorexia at least three years before volunteering for the study,and the disorder must have begun before they were 30 years old.
Individuals in the study will provide a blood sample and participate in personal interviews and questionnaires over four years.
The goal is to “find regions of the genome associated with anorexia nervosa and establish a repository that investigators throughout the world can use to explore genes in anorexia nervosa,” Kaye said.
Kaye has studied families that have a history of eating disorder behavior to figure out the rate of anorexia and bulimia in those families.
“There is a very high risk ratio,” Kaye said.
He said female relatives of female anorexics are 12 to 20 percent more likely to develop the eating disorder than relatives of women who have never had the disorder. He also said if a person has anorexia there is about a 7 percent chance that another family member has the disorder.
Past research has found an area on chromosome 1 that might play a role in developing anorexia and an area on chromosome 10 that might play a role in developing bulimia,said Dr. Cindy Bulik,a professor of psychiatry at the University of North Carolina at Chapel Hill.
“We can say that both anorexia and bulimia are definitely heritable conditions. They are influenced by genes,” said Bulik,a researcher managing genetic and psychological data for the NIMH study.
But,she said there is not just one anorexia gene or one bulimia gene.
“There is a series of genes and environmental influences that influence risk,” Bulik said.
Character traits and vulnerabilities also influence a person's likelihood of developing an eating disorder.
Kaye said many people with anorexia are anxious or perfectionists. He said these traits are seen before they develop anorexia and persist even after recovery.
“People clearly have vulnerabilities,” Kaye said. “Maybe there are some vulnerabilities that put people at risk. Most people diet,but don't get down to 60 pounds.”
Research papers from the study,which began in September 2002 will probably not appear until 2007 or 2008.
Bulik said many studies work through a number of steps before beginning a genetic study,but the NIMH is using studies done elsewhere on anorexia as background for its genetic study.
First,she said,there are family studies,which provide limited answers: Does the trait appear often in a family group? Previous studies have shown that eating disorders run in families.
“But a family study can't tell you why a disorder runs in families,” Bulik said.
She said the next step is to determine if the disorder is genetically or environmentally based by doing twin studies. Bulik said studies have shown that identical twins have the disorder more often than fraternal twins,making it more likely to be a genetic disorder.
This is because identical twins share 100 percent of their genes,and fraternal twins share,on average,50 percent.
Because of the findings in the previous two steps,and findings in another genetic study,the NIMH has decided to proceed with the third step,a molecular study. Bulik said the molecular study will be used to identify what genes might influence or cause the disorder.
Bulik said that,after identifying genes that influence risk,a researcher can work backward to understand the biological pathways. Even further down the line,she said,it is possible to look for effective drug targets.
Some day,those with eating disorders may be able to take a pill to control their symptoms,but for now,most people with eating disorders are treated through hospitalization,psychotherapy,nutrition counseling and support groups.
Dr. Dorothy Anne Richmond,a pediatrician and an associate professor in the department of pediatrics at Georgetown University,has been working with children with eating disorders for about 20 years.
Richmond works with a psychologist to diagnose eating disorders because many times there are other psychological problems,such as depression and obsessive-compulsive disorder,that go along with the eating disorder.
“We don't try to make a diagnosis the first or second time we see the patient,” Richmond said. She said getting to know the patient’s behavior is key to making a proper diagnosis.
After a diagnosis is made,Richmond sticks with the patient until she is stabilized. Richmond said she usually sees a patient weekly until she is “thin,but not emaciated.”
When the patient is medically stable,her contact with Richmond will taper off. But,Richmond said,even while a patient is seeing a medical doctor,psychotherapy is a must.
Brock Hansen is a licensed certified social worker in Washington who works with eating disordered patients to find the environmental reason for the disorder.
Oftentimes,he said,patients feel like their lives are out of control. But they are also afraid of becoming overwhelmed by anxiety if they give up their current anorexic or bulimic lifestyle.
If the motivation is there,Hansen said,a person can begin to calm herself and resolve underlying issues by learning other techniques,such as hypnosis,meditation or yoga,for dealing with the emotions that triggered the eating disorder.
“Extinguishing old habits takes a long time,” Hansen said. “The more you practice new alternatives the less you practice the old ones.”
He said it is a difficult task to help someone develop new and healthy habits,but eventually the old habits may be forgotten.
People interested in participating in the study can go to its Web site,www.angenetics.org.