Scientists found that there was no difference at age 11, but people with a greater genetic risk of schizophrenia had slightly lower IQs at age 70.
Those people who had more genes linked to schizophrenia also had a greater estimated fall in IQ over their lifetime than those at lower risk.
"With further research into how these genes affect the brain, it could become possible to understand how genes linked to schizophrenia affect people's cognitive functions as they age," said Andrew McIntosh, professor at the Edinburgh Centre for Clinical Brain Sciences.
