Older Fathers More Likely to Have Offspring with Bipolar Disorder
In a huge study of Swedish siblings, a sibling was 24.7 times more likely to have bipolar disorder if the father was older (over age 45) at the time of the birth than younger (younger than 24). Older paternal age was also associated with other risks of mental disorders, such as autism, attention deficit hyperactivity disorder (ADHD), suicide attempts, substance abuse and psychosis, but the strongest finding was of a relationship with bipolar disorder.
Mutations that occur during the production of sperm may be responsible for the increased risk of illness in the offspring of older fathers.
The population-based cohort study published by Brian M. D’Onofrio et al. in the journal JAMA Psychiatry included all individuals born in Sweden between 1973 and 2001.
