Explaining variation in the premorbid adjustment of schizophrenia patients: the role of season of birth and family history.
Several studies have shown that patients with schizophrenia are more likely to be born in the winter and early spring than at any other time of the year. Furthermore, some studies have reported that winter-born patients differ from non-winter-born patients in terms of risk factors, symptoms, sensory abnormalities and brain morphology. Associations between season of birth and premorbid adjustment (PMA), however, are still unclear.


OBJECTIVE
The main purpose of this study was to determine whether winter-born and non-winter-born schizophrenia patients differ in terms of PMA and to examine how family history of schizophrenia-spectrum disorders may influence the association.


METHODS
Data on four PMA dimensions (attention, internalizing, externalizing and social problems) and family history were gathered from 37 schizophrenia patients (26 males and 11 females) and their mothers.


RESULTS
Non-winter-birth and a positive family history of schizophrenia-spectrum disorders were associated with worse PMA. Results suggest that, although no significant interaction was found, season of birth and family history appear to work together in explaining distinct dimensions of PMA.
St-Hilaire
Annie
A
Kent State University, Department of Psychology, P.O. Box 5190, Kent, OH 44242, USA.
Holowka
Darren
D
Cunningham
Helen
H
Champagne
Frances
F
Pukall
Monica
M
King
Suzanne
S
D000293:Adolescent; D000328:Adult; D001288:Attention; D005190:Family; D005260:Female; D014644:Genetic Variation; D006801:Humans; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000453:epidemiology* / Q000235:genetics*; D012621:Seasons; D012919:Social Behavior