Season of birth of schizophrenics in Mississippi, USA.
Prior reviews indicate that schizophrenics tend to be born in the winter, relative to non-psychiatric controls. This conclusion has been criticized, however, as the association between birth seasonality and schizophrenia may be the result of a statistical artifact, the age-incidence effect. To examine this possibility, we studied the birth seasonality of 2892 schizophrenics, controlling for the age-incidence effect. Both before and after instituting these controls, we found excesses for the months of December and March. We conclude that the age-incidence hypothesis does not provide any general explanation of the season-of-birth effect in schizophrenia.
Rodrigo
G
G
Department of Family Medicine, University of Mississippi Medical Center, Jackson.
Lusiardo
M
M
Briggs
G
G
Ulmer
A
A
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D005260:Female; D006801:Humans; D007743:Labor, Obstetric; D008922:Mississippi / Q000453:epidemiology; D011247:Pregnancy; D012559:Schizophrenia / Q000453:epidemiology*; D012621:Seasons