Association between schizophrenia and social inequality at birth: case-control study.
BACKGROUND
The association between social inequality at birth and subsequent risk of schizophrenia is uncertain.


OBJECTIVE
To investigate the relationship between adult-onset schizophrenia and two indicators of social inequality at birth: social class and area of residence.


METHODS
A matched case-control design was used with data from birth certificates of first-episode cases and age- and gender-matched controls.


RESULTS
Risk increased with increasing levels of deprivation at birth. Subjects whose fathers were social class IV-V or who were born in deprived areas were at increased risk of schizophrenia (odds ratio=2.1; 95% Cl=0.8-5.5). Risk was greater in those with both of these indicators (odds ratio=8.1; 95% Cl=2.7-23.9). There was some evidence that associations were stronger in older subjects. Exclusion of African-Caribbeans or cases with positive family history somewhat attenuated the association.


CONCLUSIONS
Indicators of social inequality at birth are associated with increased risk of adult-onset schizophrenia, suggesting that environmental factors are important determinants of schizophrenic disorders.
Harrison
G
G
Division of Psychiatry, University of Bristol, 41 St Michael's Hill, Bristol BS8 3JT, UK.
Gunnell
D
D
Glazebrook
C
C
Page
K
K
Kwiecinski
R
R
D000367:Age Factors; D016022:Case-Control Studies; D006801:Humans; D016017:Odds Ratio; D011610:Psychosocial Deprivation; D012306:Risk; D012559:Schizophrenia / Q000208:ethnology / Q000209:etiology*; D012923:Social Class