Children of Older Fathers Have Higher Risk of Bipolar Disorder

Children with older fathers are more likely to develop bipolar disorder, a mental illness once known as manic depression, as genetic errors become more frequent with age, Swedish and British researchers said in a study.
The examination of Swedish health records found that children born to fathers ages 30 to 34 were 11 percent more likely to be diagnosed as adults with the condition than those born to men 20 to 24. The diagnosis was 37 percent more likely in offspring of fathers 55 and older.

The research, published in September Archives of General Psychiatry, is the first to link paternal age and bipolar disorder, the scientists said. Prior research has found a connection between a father's age and schizophrenia and autism. The association between parental age and the mental conditions in children points to a ``genetic influence.''

``Most men will have healthy children,'' said Emma M. Frans, a scientist at the Karolinska Institutet in Stockholm, who led the research team, in an e-mail last week. While the age at which parents are having children has increased in Sweden and other developed countries, ``very few men are having children at the ages when the risk for bipolar offspring is highest.''

Men continue to produce sperm throughout their lifetime. Still, the chance of DNA errors when sperm cells replicate increases as men age, researchers said.

Older Mothers

Children born to older mothers also were more likely to develop bipolar disorder, although the impact was not as great as that of older fathers. A strong association existed between older fathers and an increased risk of the condition in people 19 years or younger, so-called early onset bipolar disorder.

People with bipolar disorder can undergo swings in their mood between elation and depression. Patients may take excessive risks and even try to kill themselves. In the U.S., 5.7 million adults suffer from the disorder, according to the Web site of the National Institute of Mental Health, a U.S. agency.

The number of people 19 and younger in the diagnosed as bipolar grew to 800,000 from 20,000 between 1994 and 2003, a study published last year found.

The Swedish study took into account socioeconomic status and a family history of severe mental disorders. It was based on a review of health records of 13,428 people with the diagnosis who were born between 1932 and 1991.