Season of birth and schizophrenia in Tasmania.
OBJECTIVE
The purpose of the present study was to determine whether there was a significant seasonal variation in the birth dates of patients with schizophrenia born in Tasmania.


METHODS
The season of birth in Tasmanian-born patients with schizophrenia (n = 1412), born between 1919-1970, was compared with general population data.


RESULTS
No significant variation in month or quarter of birth was detected for the subjects with schizophrenia. Neither was there any significant seasonal excess when data from different decades were analysed separately, nor for subsidiary analyses of gender or paranoid/non paranoid subtype.


CONCLUSIONS
These results are compared with those of six other published studies of Australasian-born subjects identified through registers in different States. While both positive and negative results are reported, no clear pattern emerges. The relevance of season of birth to the development of schizophrenia in Australia remains an open question.
Jones
I H
IH
Division of Clinical Sciences, University of Tasmania, Hobart, Australia.
Hay
D A
DA
Kirkby
K C
KC
Daniels
B A
BA
Mowry
B J
BJ
D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010343:Patient Admission / Q000706:statistics & numerical data; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology* / Q000209:etiology; D012621:Seasons; D013648:Tasmania / Q000453:epidemiology