title: Schizophrenia is not disappearing in south-west Scotland.
abstract: BACKGROUND
  Recent work has reported a decline in the incidence of schizophrenia, but it is unclear if these findings reflect a true decrease in its incidence or are an artefact arising from methodological difficulties.
  
  
  OBJECTIVE
  To take account of these methodological difficulties and report service-based incidence rates for schizophrenia in Dumfries and Galloway in south-west Scotland for 1979-98.
  
  
  METHODS
  Using both clinical diagnoses and diagnoses generated from the Operational Checklist for Psychotic Disorders (OPCRIT) computer algorithm for ICD-10 and DSM-IV schizophrenia, we measured change in the incidence rates over time. We used indirect standardisation techniques and Poisson models to measure the rate ratio linear trend.
  
  
  RESULTS
  There was a monotonic and statistically significant decline in clinically diagnosed schizophrenia. The summary rate ratio linear trend was 0.77. However, using OPCRIT-generated ICD-10 and DSM-IV diagnoses, there was no significant difference over time.
  
  
  CONCLUSIONS
  OPCRIT-generated consistent diagnoses revealed no significant fall in the incidence of schizophrenia. Changes in diagnostic practice have caused the declining rates of clinically diagnosed schizophrenia in Dumfries and Galloway.
authors.affiliation: Department of Clinical Research, Crichton Royal Hospital, Dumfries, Scotland, UK. j.allardyce@clinmed.gla.ac.uk
authors.forename: J
authors.initials: J
authors.lastname: Allardyce
authors.forename: G
authors.initials: G
authors.lastname: Morrison
authors.forename: J
authors.initials: J
authors.lastname: Van Os
authors.forename: J
authors.initials: J
authors.lastname: Kelly
authors.forename: R M
authors.initials: RM
authors.lastname: Murray
authors.forename: R G
authors.initials: RG
authors.lastname: McCreadie
mesh_terms: D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology*; D012606:Scotland / Q000453:epidemiology