If you want to decrease your risks of having a child with mental disorder, you might as well have children at a young age.
Results of a new study have shown that older dads have increased risks of having children with mental health problems and learning disabilities.
In the study "Paternal Age at Childbearing and Offspring Psychiatric and Academic Morbidity" published in JAMA Psychiatry Feb. 26, researchers analyzed the data of more than 2 million children who were born in Sweden from 1973 to 2001. They also compared offsprings of the same fathers in terms of academic measures and mental health.
The researchers found that children whose fathers were 45 years old or older were 13 times more at risk of ADHD and three times more likely to have autism than children whose fathers were between 20 and 24 years old. They were also more likely to get lower grades in school and develop substance abuse problems.
"We were shocked by the findings," said study author Brian D'Onofrio, an associate professor at the Department of Psychological and Brain Sciences of Indiana University in Bloomington. "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."
The researchers also involved siblings and cousins as this allowed them to compare children who live in the same house or have similar background and found that the father's age indeed makes a difference.
"The findings in this study are more informative than many previous studies," D'Onofrio said. "First, we had the largest sample size for a study on paternal age. Second, we predicted numerous psychiatric and academic problems that are associated with significant impairment. Finally, we were able to estimate the association between paternal age at childbearing and these problems while comparing differentially exposed siblings, as well as cousins. These approaches allowed us to control for many factors that other studies could not."
Avraham Reichenberg, a professor of psychiatry at the Mount Sinai School of Medicine in New York, however, pointed out that although the study found an association between the father's age and the child's mental health, it did not prove a cause and effect relationship. Reichenberg said that other factors may also be at play such as kids with an older father may tend to grow up in a different environment than children with a younger father.
Still, the researchers said it is important to consider the possible consequences of delaying childbearing.
"The implications of the study is that delaying childbearing is also associated with increased risk for psychiatric and academic problems in the offspring," D'Onofrio said. "The study adds to a growing body of research, that suggests families, doctors, and society as a whole must consider both the pros and cons of delaying childbearing."
