Scientists link low IQ with genetic risk for Schizophrenia

May 22, 2013

As per a new study, it has been found that both the decline in cognitive ability with age and schizophrenia have some common genetic variants that link both the conditions. However, reduced cognitive ability may not necessarily be an indicator of the problem. The study provides new evidence that there may be a genetic risk for schizophrenia that is associated with lower IQ among people who do not develop the disorder.
What is the study?
The researchers analyzed data from 937 individuals in Scotland who first completed IQ testing in 1947, at age 11. Around age 70, they were retested and their DNA was analyzed to estimate their genetic risk for schizophrenia.
It was found that individuals with a higher genetic risk for schizophrenia had a lower IQ at age 70 but not at age 11. Having more schizophrenia risk-related gene variants was also associated with a greater decline in lifelong cognitive ability.
What does it suggest?
These findings suggest that common genetic variants may underlie both cognitive aging and risk of schizophrenia. Although the study does not show that these common gene variants produce schizophrenia per se, it elegantly suggests that these variants may contribute to declines in intelligence, a clinical feature linked with schizophrenia. The finding, however, still needs the support from more studies to establish how the gene variants contribute to the development of the disorder.