Researchers from New York and Israel have examined the relationship between the age of fathers at conception and the risk of schizophrenia in their offspring. Their study, published in the April 2001 Archives of General Psychiatry, found a strong relationship between advancing paternal age on the incidence of schizophrenia and other related psychosis among their offspring. The researchers examined the father's age at conception because of the increased risk of mutations with age. Starting at puberty, male germ cells begin to produce sperm through cell division, a process that continues throughout a man's lifetime.
Germ cells are the cells in the testes that make sperm and in the ovaries make eggs.
Male germ cells can undergo hundreds of cell divisions. The more a cell divides, the more opportunity for a mutation to occur. In the study, data were collected from the Jerusalem Perinatal Study, a population-based research database and a national registry of psychiatric illness. Comparisons of the father's age at conception for all the individuals revealed that schizophrenia increased with advancing paternal age. By the time a father was over age 50, there was a threefold increase in schizophrenia in his offspring.