The relationship between the heritable risk for
schizophrenia and low intelligence (IQ) has not been clear. Schizophrenia is
commonly associated with cognitive impairments that may cause functional
disability. There are clues that reduced IQ may be linked to the risk for
developing schizophrenia. For example, reduced cognitive ability may precede
the onset of schizophrenia symptoms. Also, these deficits may be present in
healthy relatives of people diagnosed with schizophrenia.
In a remarkable new study published in Biological Psychiatry,
Dr. Andrew McIntosh and his colleagues at the University of Edinburgh provide
new evidence that the genetic risk for schizophrenia is associated with lower
IQ among people who do not develop this disorder.