Brain Differences in Women With Anorexia?
Updated 7/8/2005 10:39:56 PM
By Miranda Hitti
WebMd, summary of Biological Psychiatry article, July 8, 2005 --
The eating disorder anorexia nervosa may be tied to the brain.
Researchers recently compared brain imaging of healthy women with
those who had been anorexic in the past.
The images showed that the former anorexia patients had
increased activity in brain areas that make dopamine.
Dopamine is a chemical involved in weight, feeding behaviors,
reinforcement, and reward.
"This finding might help explain why individuals with anorexia
nervosa are able to lose weight, resist eating, overexercise, are
protected from substance abuse, and are insensitive to normal
rewards," write the researchers.
Their study appears in Biological Psychology's online edition.
About Anorexia
Anorexia is an eating disorder with both physical and emotional
traits including:
Severely limited food intake
Distorted body image
Refusal to maintain a normal body weight
Intense fear of gaining weight despite being very underweight
Long-term or severe anorexia can lead to serious health problems.
It can even be fatal.
Anorexia's cause is not known. Recovery is possible with proper
treatment.
Both men and women can have anorexia or other eating disorders.
Women with anorexia may have infrequent or absent menstrual
periods. They may not be able to have normal menstrual cycles until
they regain a healthy weight.
An estimated 0.5% to 3.7% of women have anorexia at some point
during their lives, states the web site of the National Institute
of Mental Health (NIMH). The NIMH does not provide numbers for men
with anorexia.
Researcher's View
"When they are ill, people with anorexia don't seek or respond
to the kinds of comforts and pleasures most of us enjoy, including
food," says researcher Walter Kaye, MD, in a news release.
"They also resist and ignore feedback that signifies their
precarious state of health," he continues. "They don't see an
emaciated figure in the mirror. They ignore the most obvious
warning signs and dismiss comments from loved ones that suggest
they are seriously and medically ill.
"People with anorexia nervosa have extreme self-denial, not only of
food, but often of many comforts and pleasures in life, yet [they]
can be very energetic and productive," Kaye says.
"Taken together, the alterations in the dopamine system may help
explain the tell-tale symptoms of anorexia."
Kaye works at the University of Pittsburgh's medical school.
About the Study
None of the women had active anorexia. The researchers took that
approach because malnourishment alters brain chemistry, the news
release states.
Former anorexia patients had to have been recovered from the eating
disorder for at least one year prior to the study. They had
maintained a healthy weight and had regular menstrual periods.
The women also had not taken psychological drugs (such as
antidepressants) or abused alcohol or drugs for at least three
months before the study.
Flip Side of Brain-Obesity Pattern
When other researchers scanned the brains of obese people in the
past, they found the opposite pattern.
Obesity was linked to decreased activity in the brains' dopamine
reward centers, write Kaye and colleagues.
The findings support the possibility that dopamine binding might
be inversely related to weight and eating with anorexia on one end,
and obesity on the other end of the spectrum.
They call for larger studies on the topic.
-------------------------------------------------------------------
SOURCES: Frank, G. Biological Psychiatry, online edition, June
29, 2005. WebMD Medical Reference from Healthwise: "Anorexia
Nervosa: Topic Overview." National Institute of Mental Health:
"Eating Disorders: Facts About Eating Disorders and the Search for
Solutions." News release, University of Pittsburgh Medical
Center.
Updated 7/8/2005 10:39:56 PM
Updated 7/8/2005 10:39:56 PM
By Miranda Hitti
WebMd, summary of Biological Psychiatry article, July 8, 2005 --
The eating disorder anorexia nervosa may be tied to the brain.
Researchers recently compared brain imaging of healthy women with
those who had been anorexic in the past.
The images showed that the former anorexia patients had
increased activity in brain areas that make dopamine.
Dopamine is a chemical involved in weight, feeding behaviors,
reinforcement, and reward.
"This finding might help explain why individuals with anorexia
nervosa are able to lose weight, resist eating, overexercise, are
protected from substance abuse, and are insensitive to normal
rewards," write the researchers.
Their study appears in Biological Psychology's online edition.
About Anorexia
Anorexia is an eating disorder with both physical and emotional
traits including:
Severely limited food intake
Distorted body image
Refusal to maintain a normal body weight
Intense fear of gaining weight despite being very underweight
Long-term or severe anorexia can lead to serious health problems.
It can even be fatal.
Anorexia's cause is not known. Recovery is possible with proper
treatment.
Both men and women can have anorexia or other eating disorders.
Women with anorexia may have infrequent or absent menstrual
periods. They may not be able to have normal menstrual cycles until
they regain a healthy weight.
An estimated 0.5% to 3.7% of women have anorexia at some point
during their lives, states the web site of the National Institute
of Mental Health (NIMH). The NIMH does not provide numbers for men
with anorexia.
Researcher's View
"When they are ill, people with anorexia don't seek or respond
to the kinds of comforts and pleasures most of us enjoy, including
food," says researcher Walter Kaye, MD, in a news release.
"They also resist and ignore feedback that signifies their
precarious state of health," he continues. "They don't see an
emaciated figure in the mirror. They ignore the most obvious
warning signs and dismiss comments from loved ones that suggest
they are seriously and medically ill.
"People with anorexia nervosa have extreme self-denial, not only of
food, but often of many comforts and pleasures in life, yet [they]
can be very energetic and productive," Kaye says.
"Taken together, the alterations in the dopamine system may help
explain the tell-tale symptoms of anorexia."
Kaye works at the University of Pittsburgh's medical school.
About the Study
None of the women had active anorexia. The researchers took that
approach because malnourishment alters brain chemistry, the news
release states.
Former anorexia patients had to have been recovered from the eating
disorder for at least one year prior to the study. They had
maintained a healthy weight and had regular menstrual periods.
The women also had not taken psychological drugs (such as
antidepressants) or abused alcohol or drugs for at least three
months before the study.
Flip Side of Brain-Obesity Pattern
When other researchers scanned the brains of obese people in the
past, they found the opposite pattern.
Obesity was linked to decreased activity in the brains' dopamine
reward centers, write Kaye and colleagues.
The findings support the possibility that dopamine binding might
be inversely related to weight and eating with anorexia on one end,
and obesity on the other end of the spectrum.
They call for larger studies on the topic.
-------------------------------------------------------------------
SOURCES: Frank, G. Biological Psychiatry, online edition, June
29, 2005. WebMD Medical Reference from Healthwise: "Anorexia
Nervosa: Topic Overview." National Institute of Mental Health:
"Eating Disorders: Facts About Eating Disorders and the Search for
Solutions." News release, University of Pittsburgh Medical
Center.
Updated 7/8/2005 10:39:56 PM
