Children of men who father fathers relatively late in life for the first time may be more likely to develop schizophrenia than children whose fathers were younger, suggest a study by Danish scientists in the American Journal of Psychiatry.
Scientists discovered this dependence by analyzing information on more than 2 million Danes born in the years 1955 – 1992, of which 14,2 thousand was later diagnosed with schizophrenia. Interestingly, a greater risk related to paternal age was observed only in the firstborn.
Among fathers aged 25-29, the percentage of children who developed schizophrenia was 0,5%. In the case of men over 30, it was 0,7%, after 40 – 1,2%, and after 50, 2%. The relationship persisted even after taking into account the family history of mental illness.
The relationship between the age of the parents and the risk of schizophrenia in the child has been shown by many studies conducted so far. However, according to Dr. Liselotte Petersen of Aarhus University in Denmark, current findings suggest that the reason may be that men who are genetically predisposed to schizophrenia but have not developed the disease are more likely to have children later in life.
One of the mysteries is whether there are genetic or environmental factors that negatively affect male fertility and contribute to the risk of schizophrenia in their children, says Dr. Petersen. It is also possible that men with a predisposition to schizophrenia are more likely to have personality traits that affect their relationships and make it more difficult for them to find a partner.
The researcher emphasizes that most children of older fathers are not exposed to schizophrenia, as this disorder affects only about 1 percent. population. A better understanding of the relationship between parental age and schizophrenia may, however, help identify the causes of the disease (PAP).