E. Agerbo et al., Household crowding in early adulthood and schizophrenia are unrelated in Denmark: a nested case-control study, SCHIZOPHR R, 47(2-3), 2001, pp. 243-246
A number of studies have found that being born in an urban area is a risk f
actor for developing schizophrenia. It has been hypothesized that increased
exposure to infectious agents through household crowding might account for
this association. Using Danish longitudinal registers, we have established
a population-based sample of 191 cases of schizophrenia where the first ad
mission occurred between 1981 and 1993. These cases were compared with 17 4
13 individually matched controls of the same gender and age. Information re
garding parents' and siblings' psychiatric history, urbanization, season an
d place of birth, and square meter per dweller were included in a condition
al logistic regression model. We found square meter per dweller to be insig
nificant and without any trend when included as a risk factor for schizophr
enia, whereas previous findings of schizophrenia associated with being born
in an urban area and with schizophrenia in parents and siblings were repli
cated. (C) 2001 Elsevier Science B.V. All rights reserved.