title: Comparing schizophrenia symptoms in the Iban of Sarawak with other populations to elucidate clinical heterogeneity.
abstract: BACKGROUND
  The symptom profile of schizophrenia can vary between ethnic groups. We explored selected symptom variables previously reported to be characteristic of schizophrenia in the Iban of Sarawak in transethnic populations from Australia, India, and Sarawak, Malaysia. We tested site differences to confirm previous research, and to explore implications of differences across populations for future investigations.
  
  
  METHODS
  We recruited schizophrenia samples in Australia (n = 609), India (n = 310) and Sarawak (n = 205) primarily for the purposes of genetic studies. We analyzed seven identified variables and their relationship to site using logistic regression, including: global delusions, bizarre delusions, thought broadcast/insertion/withdrawal delusions, global hallucinations, auditory hallucinations, disorganized behavior, and prodromal duration.
  
  
  RESULTS
  We identified a distinct symptom profile in our Sarawak sample. Specifically, the Iban exhibit: low frequency of thought broadcast/insertion/withdrawal delusions, high frequency of auditory hallucinations and disorganized behavior, with a comparatively short prodrome when compared with Australian and Indian populations.
  
  
  CONCLUSIONS
  Understanding between-site variation in symptom profile may complement future transethnic genetic studies, and provide important clues as to the nature of differing schizophrenia expression across ethnically distinct groups. A comprehensive approach to subtyping schizophrenia is warranted, utilizing comprehensively ascertained transethnic samples to inform both schizophrenia genetics and nosology.
authors.affiliation: The Park - Centre for Mental Health, Queensland Centre for Mental Health Research, Wacol, QLD, Australia.
authors.forename: Duncan
authors.initials: D
authors.lastname: McLean
authors.forename: Robert
authors.initials: R
authors.lastname: Barrett
authors.forename: Peter
authors.initials: P
authors.lastname: Loa
authors.forename: Rangaswamy
authors.initials: R
authors.lastname: Thara
authors.forename: Sujit
authors.initials: S
authors.lastname: John
authors.forename: John
authors.initials: J
authors.lastname: McGrath
authors.forename: Jake
authors.initials: J
authors.lastname: Gratten
authors.forename: Bryan
authors.initials: B
authors.lastname: Mowry
mesh_terms: D000328:Adult; D001315:Australia; D003702:Delusions / Q000175:diagnosis* / Q000208:ethnology; D005260:Female; D006212:Hallucinations / Q000175:diagnosis* / Q000208:ethnology; D006801:Humans; D008296:Malaysia; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000175:diagnosis* / Q000208:ethnology; D063189:Symptom Assessment
keywords: culture; diagnosis; population characteristic; psychotic disorder; schizophrenia
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