A study published in the JAMA Psychiatry Journal has revealed that disorders and problems in children of school-going age could be linked to delayed fatherhood.
The study dubbed, “Paternal Age at Childbearing and Offspring Psychiatric and Academic Morbidity” conducted by researchers from the Indiana University in the United States and Sweden’s Karolinska Institute observed that advancing paternal age is associated with increased genetic mutations during spermatogenesis, which research suggested may cause psychiatric morbidity in the offspring.
It said the effects of advancing paternal age at childbearing on offspring morbidity remained unclear because of inconsistent epidemiologic findings and the inability of previous studies to rigorously rule out confounding factors.
The objective of the study which was made available to the Ghana News Agency on Thursday, was to examine the associations between advancing paternal age at childbearing and numerous indexes of offspring morbidity.
The researchers looked at 2.6 million people and at the difference between siblings born to the same father as it accounts for differences in upbringing between families.
The researchers performed a population-based cohort study of all individuals born in Sweden in 1973-2001, with subsets of the data used to predict childhood or adolescent morbidity.
It estimated the risk of psychiatric and academic morbidity associated with advancing paternal age using several quasi-experimental designs, including the comparison of differentially exposed siblings, cousins, and first-born cousins.
The main outcomes and measures of the study included psychiatric problems such as autism, attention-deficit/hyperactivity disorder, psychosis, bipolar disorder, suicide attempt, and substance use problem.
Other outcomes were academic such as failing grades and low educational attainment and morbidity.
In the study population, advancing paternal age was associated with increased risk of some psychiatric disorders such as autism, psychosis, and bipolar disorders but decreased risk of the other indexes of morbidity.
In contrast, the sibling-comparison analyses indicated that advancing paternal age had a dose-response relationship with every index of morbidity, with the magnitude of the associations being as large or larger than the estimates in the entire population.
Compared with offspring born to fathers 20 to 24 years old, offspring of fathers 45 years and older were at heightened risk of autism, attention-deficit/hyperactivity disorder, psychosis, bipolar disorder, suicide attempts, substance use problems, failing a grade, and low educational attainment in within-sibling comparisons.
It said additional analyses using several quasi-experimental designs obtained commensurate results, further strengthening the internal and external validity of the findings.
It said advancing paternal age was associated with increased risk of psychiatric and academic morbidity, with the magnitude of the risks being as large or larger than previous estimates.
The study’s findings are consistent with the hypothesis that new genetic mutations that occur during spermatogenesis are causally related to offspring morbidity.
JAMA Psychiatry (formerly known as Archives of General Psychiatry until 2013) is a monthly, peer-reviewed medical journal published by the American Medical Association.