Paternal age and schizophrenia: a population based cohort study

Objective To investigate the association of paternal age at conception with the risk of offspring developing schizophrenia. Design A population based cohort study. socioeconomic factors, family history of psychosis, and early parental death. We also investigated whether any associations differed in relation to family history, sex, birth weight, and Apgar score. We investigated the latter two because they have been identified as possible environmental risk factors, 13 14 and it has been hypothesised that in the presence of genetic predisposition, exposure to such factors may lead to the clinical manifestation of schizophrenia. 15 16