High IQ could protect against schizophrenia amongst those at genetic risk from developing the condition, a new study finds.
The findings are in stark contrast to the conventional wisdom that those with high intelligence are at increased risk of developing schizophrenia.
The largest study of its kind to date found that intelligence actually had a protective effect.
The study’s lead author, Dr. Kenneth S. Kendler, said:
“If you’re really smart, your genes for schizophrenia don’t have much of a chance of acting.”
Published in the American Journal of Psychiatry, the study was conducted by researchers at Lund University in Sweden and Virginia Commonwealth University (Kendler et al., 2014).
It included data from 1.2 million Swedish males born between 1951 and 1975 whose IQ and any hospitalisations for schizophrenia were tracked over 24 years.
Dr. Kendler explained the results:
“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.”
It may be that factors which reduce intelligence, such as childhood trauma, can also contribute to the risk of schizophrenia.
There was no evidence that, for the most intelligence people, there was a higher risk of schizophrenia:
“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.”
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