Early brain screening may predict schizophrenia
Screening for early brain changes
may predict schizophrenia, scientists have claimed. A new brain
imaging study published in the
American Journal of Psychiatry
(2000;157(111);1829-34) shows
that there are substantial brain
changes in schizophrenia at the
earliest stages of the illness,
implying that these changes pre-
cede the appearance of psychotic
symptoms.
PET scans also show changes in the schizophrenic human brain (DR MONTY BUSCHBAUM, PETER ARNOLD INC/ SCIENCE PHOTO LIBRARY)
The findings from the Institute of Psychiatry indicate that
brain changes are evident while
the illness is in its earliest stages,
and the study raises the possibility of using brain imaging to prevent schizophrenia at some time
in the future.
There were 68 people in the
study; 37 were experiencing
their first episode of psychosis
and the rest were healthy volunteers. Magnetic resonance imaging (MRI) scans identified
differences in the structure of
key regions, such as the temporal lobe, between the healthy
volunteers and those experiencing psychosis.
Dr Tonmoy Sharma, who led
the study, thinks that in future
brain imaging may provide a
way of identifying early signs of
schizophrenia and could fundamentally alter the approach to
the condition. "From this study,
we can see that characteristic
brain differences are present at a
very early stage and also shows
the promise that brain imaging
may become a powerful predictor of future illness."
While previous research has
shown that there are differences
in the brains of people with
schizophrenia and healthy volunteers, these studies have often
involved people who have had
schizophrenia for many years.
So it is difficult to identify
whether brain changes are due
to the ageing process, a result of
the illness, or the side effects of
the medication.
In the new study all the participants had experienced psychosis for only three months or
less, and some had never taken
antipsychotic drugs. The MRI
scans showed quite distinct brain
changes in key regions, suggesting that by the time someone
started to show signs of psychotic behaviour, their brains were
already structurally different.
Researchers are now starting
to focus on the prodrome phase,
the stage before psychosis
becomes apparent, in an
attempt to prevent schizophrenia. Dr Sharma said, "In cancer,
we've seen that screening people
at risk can have a great effect on
treatment success. With a suit-
able schizophrenia screening
method, for the first time, preventive psychiatry becomes a
realistic possibility.
Tracey Maher, London
studentBMJ 2000;08:435-476 December ISSN 0966-6494
