Researchers Find Epilepsy, Depression Share Common Brain Abnormalities
http://enews.voanews.com/t?ctl=BD564F:2F72C9DWorld Health Organization estimates 50 million people worldwide
have epilepsy, a periodic overload of electrical activity in the
brain, leading to unconsciousness and uncontrolled movements
Medicine has long known that people with the brain disorder epilepsy
suffer symptoms other than seizures. They also tend to experience more
depression than other people. But evidence is mounting that the
reverse is true, too. People with a history of depression are more
likely to develop epilepsy. The findings are expected to lead to
common, better methods of treating both conditions.
The World Health Organization (WHO) estimates that 50 million people
worldwide have epilepsy, a periodic overload of electrical activity in
the brain, leading to unconsciousness and uncontrolled movements.
Studies suggest that developing nations have twice the rate of
epilepsy of industrial countries.
Its connection to depression has been noted since ancient times. The
Greek physician Hippocrates reportedly observed 1,700 years ago that
epileptics become melancholics. Indeed, epileptics suffer
depression not only more than healthy people, but also more than
people with other chronic conditions, such as diabetes. As a
result, scientists have viewed depression as a complication of
epilepsy.
But neurologist Andres Kanner of Rush-Presbyterian St. Luke's Medical
Center in New York says the relationship also occurs in the other
direction.
"Data from studies done in Sweden and in the United States at Columbia
University show that in fact people with depression have a
three-to-seven-fold higher risk of developing epilepsy," he said.
Mr. Kanner spoke at a recent Washington convention of the American
Association for the Advancement of Science.
"The bi-directional relationship between depression and epilepsy is
probably explained by the fact that depression, as well as epilepsy,
share common biological mechanisms that may be operant in the two
disorders," he added.
Such mechanisms include abnormalities in brain structures called the
temporal and frontal lobes. Brain scans in the United States, Canada
and Europe have revealed that these lobes are more likely to be
shrunken in both epileptics and the depressed. In addition, Mr. Kanner
cites rat studies that show both disorders are related to abnormal
secretions of certain neurotransmitters, chemicals that carry signals
between nerves in the brain.
"So it's not that depression causes epilepsy or epilepsy causes
depression, but they share these common abnormalities that, in the
presence of one, the other condition will be more likely to occur," he
noted.
Mr. Kanner says the common biological pathways between the two
conditions might explain why people with a psychiatric history often
do not respond well to medication or surgery to treat seizures.
But the new understanding of the relationship is fueling work to find
common treatments to improve care for both disorders. For example,
University of Illinois pharmacologist Phillip Jobe says epilepsy drugs
are now being used successfully to treat depression, and there is
recent evidence showing that some anti-depression drugs might have
anti-epileptic properties.
"We have come to recognize a crossover phenomenon," Mr. Jobe
added. "So, that has really opened an entire new field of
therapeutics. We, I think, through these understandings, have the
capacity to move forward in the development of treatments that are
more effective, and diagnostic procedures that are amenable to use
early in life, so that those people eventually then can be protected
against ever experiencing these disorders."
The scientists say the research emphasizes how depression requires
aggressive treatment, because patients with this mood disorder also
have two to three times the risk of stroke, and increased danger of
diabetes, heart attack and another brain disorder called Parkinson's.
The director of the Long Island Jewish Comprehensive Epilepsy Center
in New York, Alan Ettinger, says physicians must become aware of their
patients' potential psychiatric needs to better protect their health.
"I hope these studies are a wake-up call to the general medical
community, and I hope it is also a call to arms to patients, who need
to be much more vocal with their physicians that their psychological
concerns associated with illness are attended to," he explained.
"Not treating depression will require more visits to the doctor and
higher medical costs," says Andres Kanner.