A new study by a team of researchers has found that advancing paternal age at childbearing can lead to higher rates of psychiatric and academic problems in offspring than previously estimated.
Examining an immense data set- everyone born in Sweden from 1973 until 2001- the researchers documented a compelling association between advancing paternal age at childbearing and numerous psychiatric disorders and educational problems in their children, including autism, ADHD, bipolar disorder, schizophrenia, suicide attempts and substance abuse problems.
Academic problems included failing grades, low educational attainment and low IQ scores.
The Indiana University study in collaboration with medical researchers from Karolinska Institute in Stockholm found that when compared to a child born to a 24-year-old father, a child born to a 45-year-old father is 3.5 times more likely to have autism, 13 times more likely to have ADHD, two times more likely to have a psychotic disorder, 25 times more likely to have bipolar disorder and 2.5 times more likely to have suicidal behavior or a substance abuse problem.
For most of these problems, the likelihood of the disorder increased steadily with advancing paternal age, suggesting there is no particular paternal age at childbearing that suddenly becomes problematic.
"The specific associations with paternal age were much, much larger than in previous studies. In fact, we found that advancing paternal age was associated with greater risk for several problems, such as ADHD, suicide attempts and substance use problems, whereas traditional research designs suggested advancing paternal age may have diminished the rate at which these problems occur," lead researcher Brian D'Onofrio said.
The study was published in JAMA Psychiatry.