More threads by David Baxter PhD

David Baxter PhD

Late Founder
Genes cause more than half the risk of developing anorexia, study finds
March 15, 2006

CHARLOTTE, North Carolina (Associated Press) -- Researchers studying anorexia in twins conclude that more than half a person's risk for developing the sometimes fatal eating disorder is determined by genes.

Most experts already believe there is a strong genetic component to the disorder, which mostly affects girls and women. The new study "hammers home the fact that these are biologically based disorders," said Cynthia Bulik, lead author of the study who is a psychiatrist at the School of Public Health at the University of North Carolina-Chapel Hill.

"We need to stop viewing them as a choice. ... The patients feel guilty, the providers tell them things like they should just eat, parents are blamed, the insurance companies won't fund treatment because they think it's a choice. It's held us back for decades."

People with anorexia have a distorted body image and refuse to maintain a minimally acceptable body weight; they have an intense fear of gaining weight. Bulik said anorexics are about 10 times more likely to die in a given period of time than peers the same age.

Anorexia's rarity - slightly more than 1 percent of females and well under 1 percent for males - has made it hard for scientists to gather large groups of patients for study.

The study by researchers at UNC and Sweden's Karolinska Institute looked at a Swedish registry of 31,406 twins - both identical and fraternal - born between 1935 and 1958. Identical twins are genetic clones, while fraternal twins are no more similar genetically than a brother and sister born in separate pregnancies.

Anorexia was more prevalent between identicals, and statistical analysis led to the scientists' conclusion that 56 percent of the liability for developing anorexia is due to genetics, with environmental factors determining the rest, Bulik said.

That means that not everyone with a genetic predisposition to anorexia develops it.

"A person may have genetic liability for anorexia nervosa, but they also may have - from a different parent, for example - genes that buffer them from expression of the disorder," she said. The person's environment might also provoke anorexia or prevent it.

Michael Strober, a clinical psychologist at the University of California at Los Angeles and editor of the International Journal of Eating Disorders, said "the conventional wisdom in the field now is that genetic factors do play a role in susceptibility to anorexia nervosa."

This latest study, published in the March issue of the Archives of General Psychiatry, further confirms previous research, Strober said.

The study also found a statistically significant link between anorexia and childhood "neuroticism," which Bulik describes as "a tendency to be depressed or anxious, and also to be emotionally reactive."

"For some kids, insults come right off them like water off a duck's back," she said. "These kids are more like emotional Velcro. Things stuck to them, get under their skin, and it influences them."

For Strober, the new study also lends support for the belief that personality traits, including neuroticism, are important in the development of anorexia. He believes that nearly all anorexia sufferers exhibit neurotic behavior in childhood.

Bulik and Strober are both involved in a large, federally funded multiyear study of anorexia. Headed by Dr. Walter Kaye, a psychiatry professor at the University of Pittsburgh Medical Center, that study is seeking families with two or more members with anorexia.

"This is a disorder where we haven't seen great treatments," Kaye said. "At least some of us have thought there's a very powerful biology at work here. ... The next step, of course, will be to determine what the biology is, what genes are involved and what difference they make as far as how the brain works."

On the Web:

Genetic Study of Anorexia in Families: http://www.angenetics.org
 

David Baxter PhD

Late Founder
^^Phoenix^^ said:
was this tested on identical twins reared apart? was the nuture factor controlled for?

I'm pretty sure, yes.

The study by researchers at UNC and Sweden's Karolinska Institute looked at a Swedish registry of 31,406 twins - both identical and fraternal - born between 1935 and 1958. Identical twins are genetic clones, while fraternal twins are no more similar genetically than a brother and sister born in separate pregnancies.

Anorexia was more prevalent between identicals, and statistical analysis led to the scientists' conclusion that 56 percent of the liability for developing anorexia is due to genetics, with environmental factors determining the rest, Bulik said.

If I'm not mistaken, this cohort of twins is the same one that has been used to examine heredity vs. environment in other disorders, including schizophrenia and psychopathy. The sample includes twins raised together and twins raised separately, both MZ and DZ in each case.
 
no kidding?
I do recall that other studies like this have been linked to sweden in some way...
lol, thats kinda cool
and also a little unfortunate for the twins in the registry that have anorexia, schizophrenia and others
;)
 

Similar threads

New Autism Genes Discovered Medscape Medical News October 06, 2015 The largest genetic study of autism spectrum disorder (ASD) to date has identified 65 genes that contribute to autism, including 28 for which there is "very high confidence" that they play a role in the risk of developing ASD, a multicenter US research team reports. Twenty-seven of these genes are new discoveries, first author Stephan Sanders, PhD, of the University of California, San Francisco, told Medscape Medical News...
Replies
0
Views
6K
New Schizophrenia Genes Identified Medscape Medical News July 22, 2014 A multinational team of researchers has identified 83 new genes associated with schizophrenia and a variant in 1 gene that also increases the risk for bipolar disorder and alcoholism. The findings are reported in 2 separate articles ― one published online July 22 in Nature, the other published online July 18 in Psychiatric Genetics. In Nature, the Schizophrenia Working Group of the Psychiatric Genomics Consortium...
Replies
0
Views
2K
Shared Genes May Link ADHD, Autism, and Depression By Steven Reinberg, WebMD News Feb. 27, 2013 Autism, attention-deficit/hyperactivity disorder (ADHD), major depression, bipolar disorder, and schizophrenia may all share common genetic risk factors, a new study says. In this largest study of its kind, researchers spotted gene variations governing brain function that may raise the risk for these often devastating mental woes. In the future, these gene variants might become key targets...
Replies
0
Views
2K
Identification of risk loci with shared effects on five major psychiatric disorders: a genome-wide analysis The Lancet, Early Online Publication, 28 February 2013 Cross-Disorder Group of the Psychiatric Genomics Consortium? Summary Background Findings from family and twin studies suggest that genetic contributions to psychiatric disorders do not in all cases map to present diagnostic categories. We aimed to identify specific variants underlying genetic effects shared between the five...
Replies
2
Views
2K
Schizophrenia Pops Up In Memory Genes Chris Jones-Cardiff November 22, 2011 CARDIFF (US) — Genetic mutations that cause schizophrenia could be linked to systems in the brain responsible for learning and memory, a study suggests. Researchers have identified changes to genes—genetic mutations—in patients with schizophrenia who had not inherited the condition. The study, published in the journal Molecular Psychiatry, shows these mutations occurred among a set of proteins that play a...
Replies
0
Views
1K
Top