A recent study done by the Copenhagen Centre for Social Evolution showed that parents who have kids later in life are more likely to have children with autism disorders. However, the link between later reproduction and schizophrenia in children was disproved.
The study was published in Evolution, Medicine and Public Health and analyzed a comprehensive single population sample from Denmark. Analysis was drawn from data that compared maternal and paternal age, as well as age difference.
The sample of 1.7 million children was used. In this cohort, 6.5 percent were diagnosed with autistic or schizophrenic disorders. Researchers also statistically controlled for confounding medical and socioeconomic factors in their sample.
Older mothers and fathers had an association with increased risk of most autistic disorders in offspring. Furthermore very old fathers showed an more magnified association. In addition, children of young parents were shown to have reduced risks of autism.
As for schizophrenia, there did not seem to be a correlation between age and risk. However, very young mothers seemed to have children with an increased risk.
The study also showed that parents who differed greatly in ages tended to have offspring who had a higher risk of autism and schizophrenia.
“The magnitude of these increases and decreases in statistical risk need to be scaled against the fortunately rather modest absolute risks of being diagnosed with a mental disorder in Denmark, which is 3.7 percent for all autistic disorders and 2.8 percent for all schizophrenic disorders up to 30 years of age,” Sean Byars, first author of the study, said in a press release.
