Schizophrenia And Older Dads
There is growing evidence that men, like women, have a "biological clock" when it comes to having children.
It has long been known that older mothers are at greater risk for delivering children with birth defects. Now researchers have found that children fathered by older men have a higher risk of developing schizophrenia.
A child's risk of developing the mental illness rises steadily as the age of the father increases, say researchers at Columbia University College of Physicians and Surgeons, New York University School of Medicine, and Israel's Ministry of Health.
Reviewing health records of over 87,000 people born in Jerusalem between 1964 and 1976, researchers found that men between 45 and 49 years old were twice as likely as those under 25 to sire offspring who developed schizophrenia. Men aged 50 and older ran three times the risk of the fathers under 25.
According to the study, 26.6 percent of the schizophrenia cases could be attributed to paternal age. Age was responsible for two-thirds of the cases when the father was over 50. Mothers' ages didn't appear to be a factor.
Dr. Dolores Malaspina of Columbia University led the study. She said the findings add to evidence of an increased likelihood for children born to older fathers to develop health problems.
"This is the first psychiatric disease that's been linked to advancing paternal age," she said.
Previously, prostate cancer, nervous system cancer, dwarfism and Marfan syndrome have all been linked to advancing paternal age.
But Malspina says older prospective fathers shouldn't worry too much – most kids are fine. "Most children of older fathers have no sign of any disease whatsoever. So this is not meant to discourage people from having families and I wouldn't want it to be interpreted that way."
The study, appearing in the Archives of General Psychiatry, supports the theory that as men grow older, sperm cells can mutate. Those mutations are then passed on to their children.
"We've always thought of women as having a biological clock and we've been very aware that as women get older, their reproductive capacity falls off and eventually ceases altogether," said New York University's Dr. Susan Harlap.
"We've always thought that men were able to father children basically indefinitely. I don't think anyone had given thought to whether the children would be healthy," she added.
The study also suggested that as a result of the findings, perhaps the age of sperm donors should be lowered.
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