Month of birth and schizophrenia in Alberta.

Numerous studies have demonstrated that a greater than expected number of schizophrenics are born during the winter months. The present investigation examined this phenomenon in Alberta. The study population consisted of 1,101 schizophrenic patients admitted to either of the two provincial mental hospitals during 1976-1983 and who were born in Canada. After controlling for year of birth, no seasonality effect was found.