Friday, March 16, 2007

Paternal Age, Schizophrenia, and Autism

A good chunk of studies have accumulated over the past few years (e.g., 1, 2, 3, 4, 5) that show a strong link between increasing paternal (father’s) age and risk of schizophrenia in children.

One researcher has described the link as follows:

We found that paternal age explained over a quarter of the risk for schizophrenia in the population. At the time, people were skeptical. But the findings have been replicated many times now, and not a single study has failed to find this strong relationship between father's age and the risk for schizophrenia. And at this point, other explanations for the relationship have been ruled out, including social factors in the family, prenatal care, and parental psychiatric ailments. There simply seems to be a relationship between paternal age and schizophrenia risk.

Wow – one quarter of the risk for schizophrenia explained by paternal age? I’ll admit that these types of studies are not my area of expertise, but from my review of some of these studies, I’m willing to buy that paternal age is a significant risk. These findings have indeed been replicated on numerous occasions.

One of the main researchers in the area, Dolores Malaspina (quoted above), has said that findings such as this should not discourage parents from having children at whatever age they choose. I am not in agreement – older parents should be made aware of the risk and make an informed decision.

Why the effect? Here’s what seems to be a decent explanation

"Every cell division makes a copy of DNA," [researcher] Gavrilova says. "And the same thing happens with the next division and this final copy is of less quality. This can introduce a slight risk of error in the genetic material of the new sperm. You can call it a kind of copy error.

The longer a man ages, the greater the chance of sperm mutations that could lead to schizophrenia or other problems in offspring.

There is also research linking autism to older fathers. It appears that such information is not widely known. I was certainly not familiar with it until recently. Consider the trends in Western societies – fathers having children at older ages is likely leading to a decent sized increase in rates of schizophrenia, autism, and perhaps other problems as well. While this is excellent news if one is in the antipsychotic business, is this really good news for everyone else?

Shouldn't this information be more widely discussed?

Hat Tip: Just Noticeable Differences.

3 comments:

Stephany said...

This is a great post; and definitely a topic worth discussing. My children's Father was 38 yrs. old when my youngest was born. I have read various articles regarding schizophrenia/ autism links to the age of the Father.My daughter has a questionable psychiatric diagnosis, along with a "High Functioning" Autistic dx of P.D.D./ it might be interesting to note here, that my daughter was treated for "possible" psychiatric bipolar disorder at age 11-17 yrs; before the P.D.D. dx that she received at age 17.5 years old.

Treating autistic children's behaviors with psychiatric medications is a controversial topic in iteself, and worth looking into further.

I am including a link to an article from 2002 that could be of further interest:

http://info.med.yale.edu/chldstdy/plomdevelop/genetics/02novgen.htm



From the article:

"Future research should include longer-term studies of atypical antipsychotics to gather longitudinal efficacy and safety data."

Dr. Leonid Gavrilov, Ph.D. said...

Thank you for your interesting post!
I thought perhaps you may also find this related scientific study interesting to you:
Human Longevity and Parental Age at Conception
http://longevity-science.org/Parental_Age_2000.pdf

Anonymous said...

Autistic men are more likely to marry older and therefore pass on their genes. Has the study corrected for this?