94-03-10 Identical Twins Do Not Have Identical Risk of Mental Illness, New Book Shows

IDENTICAL TWINS DO NOT HAVE IDENTICAL RISK
OF MENTAL ILLNESS, NEW BOOK SHOWS

     CHARLOTTESVILLE, Va., March 10 -- A photograph of identical
twin baby girls, dressed in dainty frocks, is compelling.  Even
more so, when the viewer learns that one of the twins developed
schizophrenia at age 20.  The other twin is well.  Why would one
twin become schizophrenic when both were raised under identical
circumstances?  Are some people genetically destined to become
schizophrenic?
     Seeking those answers, researchers recruited more than 34
pairs of identical twins in which one suffered from schizophrenia
or manic-depressive disorder and the other did not.  In a landmark
study that began in 1987, the twins were evaluated and tested in
Washington, D.C., in a comprehensive effort to uncover the
biological roots of mental illness.
     The researchers concluded that while schizophrenia and manic
depressive disorder have genetic components, they are most likely
triggered by an outside biological force, such as a virus, either
in utero or in infancy.
     Tests showed a profound change in both the structure and
function of the brains in twins with schizophrenia--changes that
did not occur in the healthy, identical twins.  The researchers
believe the changes in brain structure, as measured by magnetic
resonance imaging (MRI), are an integral part of the schizophrenia
disease process.
     The study also found that obstetrical complications in
pregnancy and birth appeared to be contributing factors in at least
30 percent of the twins with schizophrenia.
     The researchers established that the disease may begin very
early in life although the symptoms do not usually appear until
young adulthood.  They also determined that schizophrenia--often
called madness or the mind--does not change many of an individual's
normal personality traits.
     The findings, together with psychological portraits of the
twins in the study, are presented in "Schizophrenia and Manic
Depressive Disorder, The Biological Roots of Mental Illness," just
published by BasicBooks.  Written by Dr. E. Fuller Torrey in
collaboration with Ann E. Bowler, Edward H. Taylor and Irving I.
Gottesman, the book provides substantial evidence that both
schizophrenia and manic-depressive disorder are biologically based
diseases of the brain.
     Although the role of psychological influences on the diseases
remains unclear, one finding, in particular, should bring relief to
relatives of schizophrenics.
     "Parents should not feel guilty if a child becomes
schizophrenic.  Our results clearly showed that the disease cannot
be blamed on the parents," said Gottesman, the Sherrell Aston
Professor of Psychology at the University of Virginia.
     There is more good news for relatives of schizophrenics. 
"Although the study showed that schizophrenia has a genetic
component, it is not inevitable that a sibling will become mentally
ill.  Our findings indicated that if one of two genetically
identical twins has escaped mental illness for six to 10 years
after his or her twin becomes ill, the odds are very much against
that person also becoming ill, said Gottesman, widely recognized
for his work in genetics and schizophrenia.
     An unusual component of the study was the researchers' ability
to gain anecdotal evidence about the history of the twin with
mental illness from the well twin and their relatives.  The
researchers were told by one in four families that the
schizophrenic exhibited distinct personality differences from the
other twin before kindergarten.
     "The study gave us an exact frame of reference for when to
expect symptoms of schizophrenia to appear," said Gottesman, an
award-winning researcher who is author of "Schizophrenia Genesis: 
The Origins of Madness."
     Although the study yielded major findings, additional research
continues, Gottesman says.  Among the factors currently being
investigated are the connection between viruses and schizophrenia
and the relationship, if any, between early physical illness or
head trauma and the onset of schizophrenia.
     Gottesman, who began his research with twins in 1958, likes to
compare the studies to solving a jigsaw puzzle.  "Each study yields
another piece to this giant puzzle.  We've learned there is no one
simple answer that provides all the pieces."
                               ###
                                                    March 9, 1994
     FOR FURTHER INFORMATION on the study and book, contact
Gottesman at (612) 893-0085.  Dr. Torrey can be reached at (202)
373-6105.  For a review copy of the book, contact the U.Va. News
Office at (804) 924-7116.  A limited number of books is available.

[Submitted by: Karen A. Castle  (kac@uva.pcmail.virginia.edu)
               Thu, 10 Mar 94 09:18:45 EST]