Season of birth in schizophrenia and neurosis.

National studies in Scandinavia and in England and Wales have shown that schizophrenic patients are born significantly more often in the early months of the year than would be expected from comparison with the general population. The author examines additional evidence from England and Wales and discusses possible sources of technical error. Although there is currently no evidence of a causal association between season of birth and schizophrenia, he suggests that this possibility should be given consideration.