No significant association between prenatal exposure poliovirus epidemics and psychosis.
OBJECTIVE
To examine the association between prenatal exposure to poliovirus infection and later development of schizophrenia or affective psychosis in a Southern Hemisphere psychiatric register.


METHODS
We calculated rates of poliomyelitis cases per 10 000 background population and rates for schizophrenia(n = 6078) and affective psychosis (n = 3707)per 10 000 births for the period 1930-1964. Empirically weighted regression was used to measure the association between a given psychosis birth-rate and a poliomyelitis epidemic during gestation.


RESULTS
There was no statistically significant association between exposure to a poliomyelitis epidemic during gestation and subsequent development of schizophrenia or affective psychosis.


CONCLUSIONS
The lack of a consistent statistically significant association between poliovirus epidemics and schizophrenia suggests that either poliovirus may have a small effect which is only detectable with large data-sets and/or the effect may be modified by location. Further investigation of such inconsistencies may help elucidate candidate risk-modifying factors for schizophrenia.
Cahill
Matthew
M
Queensland Centre for Schizophrenia Research, Wolston Park Hospital, Wacol, Australia.
Chant
David
D
Welham
Joy
J
McGrath
John
J
D000341:Affective Disorders, Psychotic / Q000209:etiology*; D001315:Australia; D005260:Female; D006801:Humans; D008297:Male; D011051:Poliomyelitis / Q000150:complications*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012559:Schizophrenia / Q000209:etiology*