Schizophrenic Brain Has Less Gray Matter
Schizophrenia patients have less gray matter in
their brains, a change that may one day be shown to predispose
individuals to the psychiatric illness. Gray matter, the interior of
the brain that contains the nerve cell bodies, is also reduced in
other illnesses, such as dementia and chronic alcoholism.
The finding adds to the growing evidence that an underlying brain
structural problem may contribute to the psychiatric illness,
according to lead researcher Dr. Kelvin O. Lim, at the VA Palo Alto
Health Care System in California.
"When people have heart disease we don't say this is in your head, we
focus on the heart and on the disease," he said. "This suggests that
something is happening in the brain that is resulting in this very
disturbing and tragic illness."
In the new study, Lim and colleagues from the State University of New
York at Stony Brook used magnetic resonance imaging (MRI) to measure
the volume of gray matter in the brains of 22 newly diagnosed
schizophrenia patients, and 51 people the same age. Not only does gray
matter vary with illness, its volume changes with age and head size.
The schizophrenic patients had lower gray matter volume and larger
ventricles, the cavities in the brain that contain cerebrospinal
fluid, according to the report in the American Journal of Psychiatry.
"Gray matter deficiency is not specific to schizophrenia. We also find
it in chronic alcoholics -- that makes sense because alcohol is toxic
to the brain," Lim said. "We have also seen this in other disorders
such as congenital (or present since before birth) rubella." Children
born to mothers who contract rubella, or German measles, during
pregnancy can exhibit psychotic symptoms and gray mattery deficiency,
The gray matter deficiency was first noted in people who had
schizophrenia for 5 to 10 years, according to Lim, who is also an
assistant professor of psychiatry and behavioral science at Stanford
University in Palo Alto, California.
"The question is, when did it happen?" he said. More study is needed
to determine if the gray matter deficiency existed prior to diagnosis,
and if it in some way predisposes individuals to the illness.
Schizophrenia occurs in 1% of the population, striking most often in
men between the ages of 15 and 24, and women between the ages of 25 to
34. The onset is characterized by distortion of reality, language and
communication disturbances, and withdrawal from social interaction.
SOURCE: American Journal of Psychiatry (1996;153:1548-1553)
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