Am J Psychiatry 2014; Advance online publication
medwireNews: The risk for developing schizophrenia is significantly affected by an individual’s IQ, show results of a study of over 1 million Swedish men.
Researchers found that each 1 point decrease in IQ score was associated with a 3.8% increase in the risk of developing schizophrenia.
“The observed IQ-schizophrenia association does not, to any appreciable degree, appear to result from declines in intelligence in individuals undergoing an insidious onset of schizophrenia at the time of testing”, note Kenneth Kendler (Virginia Commonwealth University, Richmond, USA) and co-authors in The American Journal of Psychiatry.
Contrary to previous research, which suggests an association between “genius” and schizophrenia, the current study found no evidence of a link between these two factors. “Risk for schizophrenia in our highest IQ category was lower than that in the next highest group”, the researchers explain.