Europe South Asia Asia Pacific Americas Middle East Africa BBC Homepage World Service Education



Front Page

World

UK

UK Politics

Business

Sci/Tech

Health

Education

Sport

Entertainment

Talking Point
On Air
Feedback
Low Graphics
Help

Wednesday, October 14, 1998 Published at 18:13 GMT 19:13 UK


Health

Brain chemicals may cause bulimia

Bulimia can cause misery

The eating disorder bulimia nervosa may be caused, at least in part, by chemical changes to the brain, researchers have discovered.

Scientists have found that chemical changes that take place in the brains of sufferers persist even after recovery.

Writing in the Archives of General Psychiatry, study leader Professor Walter Kaye, of the University of Pittsburgh, said brain serotonin activity and mood in bulimics are known to alter when they binge and purge. Women with bulimia are also known to have an obsession with perfectionism.

Serotonin is a neurotransmitter that helps regulate mood. The study found that these alterations and symptoms persisted after recovery from bulimia nervosa, suggesting that they are not merely a consequence of abnormal eating behaviors.

Appetite control

Theoretically, altered serotonin activity could cause anxious and obsessive behaviors, affect the control of appetite and thus contribute to an increased susceptibility to bulimia nervosa.

Dr Kaye said: "The development of an eating disorder is often attributed to the effects of our cultural environment, such as the mass media, which places a heavy emphasis on slimness.

"But while all women are exposed to these cultural mores, only a small percentage develop an eating disorder. Our study may have identified a biological risk factor that plays a part in deciding who develops a disorder."

Dr Kaye said the research was important because it would help shift focus to the underlying causes of bulimia nervosa.

This would help scientists to concentrate on developing better treatments, and ways to identify people at risk before the disorder occurs.

Bulimia nervosa affects about one to three per cent of women - most of whom are of normal body weight.

The symptoms usually appear during adolescence, and involve bingeing and purging, either by vomiting or using laxatives.

Distorted body image


[ image: Princess Diana: a sufferer]
Princess Diana: a sufferer
Women with the disease often have a distorted image of their bodies, changes in brain chemistry and psychiatric symptoms such as depression, anxiety, obsessive-compulsive disorder and alcohol or other substance abuse.

Though researchers know the symptoms and effects of bulimia, the exact causes of the disorder have yet to be uncovered.

Because malnutrition associated with eating disorders affects brain chemistry, Dr Kaye and his colleagues compared 31 healthy volunteer women to 30 women who had recovered from bulimia nervosa.

The women who had recovered were of normal body weight, had regular menstrual cycles and had not binged or purged for more than a year.

Behavioural disturbances

The researchers assessed the recovered bulimia nervosa participants for persistent behaviour disturbances and measured levels of the major metabolites of the neurotransmitters serotonin, dopamine and norepinephrine.

They also gave the participants a non-therapeutic drug, m-chlorophenylpiperazine (m-CPP), that specifically affects the serotonin system and causes hormonal and behavioral responses.

Dr. Kaye's team found that, compared to the healthy volunteers, the recovered women had increased levels of the serotonin metabolite, more negative moods and obsessions with perfectionism and exactness.

The levels of the other brain chemicals, dopamine and norepinephrine, were normal in comparison.

In addition, the group of recovered bulimia nervosa women had a more extreme response to m-CPP.



Advanced options | Search tips




Back to top | BBC News Home | BBC Homepage | ©


Health Contents

Background Briefings
Medical notes

Relevant Stories

06 Oct 98 | Medical notes
Anorexia factfile

01 Aug 98 | Health
'Hidden danger' of brain damage

08 Jul 98 | Latest News
Media slammed over superthin models





Internet Links


Information on eating disorders

Eating disorders

Eating Disorders Association


The BBC is not responsible for the content of external internet sites.




In this section

Disability in depth

Spotlight: Bristol inquiry

Antibiotics: A fading wonder

Mental health: An overview

Alternative medicine: A growth industry

The meningitis files

Long-term care: A special report

Aids up close

From cradle to grave

NHS reforms: A guide

NHS Performance 1999

From Special Report
NHS in crisis: Special report

British Medical Association conference '99

Royal College of Nursing conference '99