Birth Dates and Admission Dates in Schizophrenia and Bipolar Disorder

The well established phenomenon 0/ seasonality 0/ birth dates (winter excess) and admission dates (summer excess) o/patients with schizophrenia and bipolar disorder was re-examined in a Southern A/rican study 0/ ill-patients. Monthly and seasonal analyses relpectively resulted in a May (late autumn and winter) excess o/schizophrenic male births and a March (late summer and autumn) excess among schizophrenic f emales, which revealed a gender difference. Bipolar births peaked in May (autumn). Admission rates peaked in May (late autumn) f or schizophrenic patients and in March (early autllmn) for bipolar patients. Birth rates peaked one season earlier but admission rates olle season later Ihan in previous studies. The apparent coincidence of the birth and admission peaks among patients with schizophrenia and bipolar disorder m ggests that these pah'ents are more often admitted around their birthdays, This concurrence remains to be tested,