Neighbourhood variation in the incidence of psychotic disorders in Southeast London.
BACKGROUND
Urbanicity is a risk factor for schizophrenia, but it is unclear whether this risk is homogenous across urban areas.


OBJECTIVE
To determine whether the incidence of psychotic disorders varied within an urban area, beyond variation attributable to individual-level characteristics.


METHODS
All incident cases of ICD-10 psychoses from a large, 2-year, epidemiological study of first-episode psychoses in Southeast London were identified. Incidence rates for 33 wards were standardised for age, sex and ethnicity. Bayesian models produced accurate relative risk estimates that were then mapped.


RESULTS
295 cases were identified during 565,000 person-years of follow-up. We observed significant heterogeneity in relative risks for broad and non-affective psychoses (schizophrenia), but not for affective psychoses. Highest risks were observed in contiguous wards.


CONCLUSIONS
Neighbourhood variation in the incidence of non-affective psychoses could not be explained by individual-level risk, implicating neighbourhood-level socioenvironmental factors in their aetiology. The findings are consistent with classical sociological models of mental disorders.
Kirkbride
James B
JB
Dept. of Psychiatry, University of Cambridge, Box 189, Cambridge CB2 2QQ, UK. jbk25@cam.ac.uk
Fearon
Paul
P
Morgan
Craig
C
Dazzan
Paola
P
Morgan
Kevin
K
Murray
Robin M
RM
Jones
Peter B
PB
D000293:Adolescent; D000328:Adult; D000341:Affective Disorders, Psychotic / Q000453:epidemiology* / Q000208:ethnology; D001499:Bayes Theorem; D016000:Cluster Analysis; D003156:Community Mental Health Services / Q000706:statistics & numerical data; D004641:Emigration and Immigration; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D038801:International Classification of Diseases; D008131:London / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000453:epidemiology* / Q000208:ethnology; D012111:Residence Characteristics; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology* / Q000208:ethnology; D012931:Social Environment; D014504:Urban Health