title: Heterogeneity in incidence rates of schizophrenia and other psychotic syndromes: findings from the 3-center AeSOP study.
abstract: BACKGROUND
  Convention suggests uniformity of incidence of schizophrenia and other psychoses; variation would have implications for their causes and biological characteristics.
  
  
  OBJECTIVE
  To investigate variability in the incidence of psychotic syndromes in terms of place, ethnicity, age, and sex.
  
  
  METHODS
  Three-center, prospective, comprehensive survey of clinically relevant first-onset psychotic syndromes over a 2-year period (1997-1999). Census data provided the denominator.
  
  
  METHODS
  Southeast London, Nottingham, and Bristol, England.
  
  
  METHODS
  One million six hundred thousand person-years yielded 568 subjects aged 16 to 64 years with clinically relevant psychotic syndromes.
  
  
  METHODS
  The World Health Organization Psychosis Screen and the Schedules for Clinical Assessment in Neuropsychiatry to classify, blind to ethnicity, all DSM-IV psychotic syndromes and the subclasses of schizophrenia, other nonaffective disorders, affective disorders, and substance-induced psychosis.
  
  
  RESULTS
  All syndromes showed a characteristic age distribution. Schizophrenia was significantly more common in men (incidence rate ratio [IRR], 2.3 [95% confidence interval (CI), 1.7-3.1]); affective disorders occurred equally in men and women (IRR, 1.0 [95% CI, 0.7-1.3]). All psychoses were more common in the black and minority ethnic group (crude IRR, 3.6 [95% CI, 3.0-4.2]). Differences in age, sex, and study center accounted for approximately a quarter of this effect (adjusted IRR, 2.9 [95% CI, 2.4-3.5]) in each psychosis outcome. The age-sex standardized incidence rate for all psychoses was higher in Southeast London (IRR, 49.4 [95% CI, 43.6-55.3]) than Nottingham (IRR, 23.9 [95% CI, 20.6-27.2]) or Bristol (IRR, 20.4 [95% CI, 15.1-25.7]). Rates of all outcomes except affective disorders remained significantly higher in Southeast London when the model was expanded to control for ethnicity.
  
  
  CONCLUSIONS
  There is significant and independent variation of incidence of schizophrenia and other psychoses in terms of sex, age, ethnicity, and place. This confirms that environmental effects at the individual, and perhaps neighborhood level, may interact together and with genetic factors in the etiology of psychosis.
authors.affiliation: Department of Psychiatry, University of Cambridge, Cambridge, England. jbk25@cam.ac.uk
authors.forename: James B
authors.initials: JB
authors.lastname: Kirkbride
authors.forename: Paul
authors.initials: P
authors.lastname: Fearon
authors.forename: Craig
authors.initials: C
authors.lastname: Morgan
authors.forename: Paola
authors.initials: P
authors.lastname: Dazzan
authors.forename: Kevin
authors.initials: K
authors.lastname: Morgan
authors.forename: Jane
authors.initials: J
authors.lastname: Tarrant
authors.forename: Tuhina
authors.initials: T
authors.lastname: Lloyd
authors.forename: John
authors.initials: J
authors.lastname: Holloway
authors.forename: Gerard
authors.initials: G
authors.lastname: Hutchinson
authors.forename: Julian P
authors.initials: JP
authors.lastname: Leff
authors.forename: Rosemarie M
authors.initials: RM
authors.lastname: Mallett
authors.forename: Glynn L
authors.initials: GL
authors.lastname: Harrison
authors.forename: Robin M
authors.initials: RM
authors.lastname: Murray
authors.forename: Peter B
authors.initials: PB
authors.lastname: Jones
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D016022:Case-Control Studies; D003710:Demography; D004739:England / Q000453:epidemiology; D005006:Ethnicity / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D016012:Poisson Distribution; D011446:Prospective Studies; D011618:Psychotic Disorders / Q000453:epidemiology* / Q000208:ethnology; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology* / Q000208:ethnology; D012737:Sex Factors; D012931:Social Environment; D014505:Urban Population