People with a genetic predisposition to schizophrenia may be
protected against the disease if they have a high IQ, finds a new study
conducted by scientists at Virginia Commonwealth University and Lund University
This contradicts the popular myth that schizophrenia is
directly linked to brilliance.
"If you're really smart, your genes for schizophrenia don't
have much of a chance of acting," says lead author Kenneth S. Kendler, who is a
professor of psychiatry and human and molecular genetics at the VCU School of
In the study, the researchers gauged the IQ of 1.2 million
Swedish males born between 1951 and 1975.
Hospitalization due to schizophrenia was tracked for 24
years and ended in 2010.
"What really predicted risk for schizophrenia is how much
you deviate from the predicted IQ that we get from your relatives. If you're
quite a bit lower, that carries a high risk for schizophrenia. Not achieving
the IQ that you should have based on your genetic constitution and family
background seems to most strongly predispose for schizophrenia," noted Kendler.
While the effect is fairly robust, it does not completely
rule out the possibility of schizophrenia in highly intelligent people.
"The question is, might we see some upward bump at
that high level of intelligence where really brilliant people have increased
risk for the disease and we show no such trend," added Kendler.