Scientists have tried through the years to attribute schizophrenia to one brain abnormality or another, but solid proof has been lacking. Now University of Florida researchers have found that subtle differences in 10 brain structures can provide a strong indicator of whether someone has the disorder.
MRI scans
reveal subtle brain differences in people with schizophrenia
By Victoria White
Scientists
have tried through the years to attribute schizophrenia to one brain
abnormality or another, but solid proof has been lacking. Now University of
Florida researchers have found that subtle differences in 10 brain
structures can provide a strong indicator of whether someone has the
disorder.
In an article
published in the current issue of the Journal of Biological Psychiatry, UF
Brain Institute researchers report that by analyzing magnetic resonance
imaging scans, they were able to correctly determine 77 percent of time
which study participants had schizophrenia.
The finding
holds promise as a tool for diagnosis or for predicting who might develop
the often-devastating psychiatric illness, which typically first strikes in
the late teens to early 30s. Useful in treatment, prediction also is
critical in the quest to identify environmental contributions to
schizophrenia.
"The
first wave of MRI studies searched for the 'smoking gun' that could explain
the symptoms of schizophrenia," said Dr. John Kuldau, a professor of
psychiatry in the UF College of Medicine and chief of psychiatry for the
Malcom Randall Veterans Affairs Medical Center in Gainesville. "But the
disease is much more complicated than that. Like diabetes, it is thought to
be caused by an interplay between genetic and environmental factors."
So instead of
looking for one large difference between the groups, Kuldau and
co-investigator Christiana Leonard, a professor of neuroscience, psychiatry
and psychology, and the rest of their research team decided to examine a
number of structures that had been proposed as playing a possible role in
schizophrenia.
"If many
genes are involved, one would expect them to produce proteins in different
parts of the brain, resulting in subtle variations," Kuldau said.
The
researchers looked at overall brain volume and the placement or size of a
variety of grooves, holes and folds in the brain. The differences were so
slight between the 33 men in the control group and the 37 men with
schizophrenia that they couldn't be spotted by the eye. Instead, they were
calculated with the help of statistical techniques.
"By looking at all these structures, we were able to do something we
considered rather astonishing--accurately determine most of the time who in
the study had schizophrenia just based on brain anatomy," said Kuldau,
who is now working to replicate the findings with other study participants.
An estimated
2.5 million people in the United States suffer from schizophrenia, a
disorder characterized by delusions and hallucinations. People with the
disorder often have a sense that they are being spied on or persecuted and
report hearing voices that no one else does. Currently, there is no reliable
predictor of the disease. Commonly, those with the disorder and their
families deny anything is wrong for months or even years.
"Part of
the illness is that you don't recognize that you are sick, so there often is
a big delay between onset and getting so sick that you come in for
treatment," Kuldau said.
The delay is
problematic, because early medication treatment has been linked to improved
long-term prognosis.
Kuldau said
brain anatomy should be viewed as "an informative intermediary
step" between genes and the development of schizophrenia, rather than
as a direct cause. He noted that identical twins share the same genes, but
they are exposed to different environmental influences, their brains can
develop differently and often only one will develop the disease.
Kuldau said
large-scale studies that track people for a number of years are needed to
try to sort through all the possible contributors to the disorder.
"Only
those sorts of studies will have the power to trace the path from genetic
predisposition through physiologic, molecular and environmental
contributions to the development of the behaviors associated with
schizophrenia," he said.
Recent UF Health Science Center news releases are available at www.health.ufl.edu/hscc/index.html
Thursday, May 20, 1999 University of
Florida Health Science Center and Shands HealthCare. For more
information, please call 352/392-2755 or e-mail:
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