title: Obstetric adversity and age at first presentation with schizophrenia: evidence of a dose-response relationship.
abstract: OBJECTIVE
  The purpose of the study was to determine if a dose-response relationship exists between obstetric adversity and age at first presentation with schizophrenia.
  
  
  METHODS
  The Dublin Psychiatric Case Register was used to identify subjects with schizophrenia. Data on obstetric complications, social class of origin, and family history of psychiatric illness were obtained for those subjects.
  
  
  RESULTS
  A total of 409 patients with ICD-9 schizophrenia were identified. Patients with a history of obstetric complications presented earlier to psychiatric services. As the number of complications increased, the mean age at first presentation decreased. This effect was independent of social class of origin and family history of psychiatric illness.
  
  
  CONCLUSIONS
  Obstetric adversity exerts an independent influence on the age at first presentation with schizophrenia, in a dose-response manner. This finding supports the existence of a causal relationship between obstetric adversity and age at first presentation with schizophrenia.
authors.affiliation: Stanley Research Unit, Department of Adult Psychiatry, Hospitaller Order of St. John of God, Cluain Mhuire Service, Newtownpark Avenue, Blackrock, Co. Dublin, Ireland.
authors.forename: Brendan D
authors.initials: BD
authors.lastname: Kelly
authors.forename: Larkin
authors.initials: L
authors.lastname: Feeney
authors.forename: Eadbhard
authors.initials: E
authors.lastname: O'Callaghan
authors.forename: Roy
authors.initials: R
authors.lastname: Browne
authors.forename: Majella
authors.initials: M
authors.lastname: Byrne
authors.forename: Niamh
authors.initials: N
authors.lastname: Mulryan
authors.forename: Ann
authors.initials: A
authors.lastname: Scully
authors.forename: Mary
authors.initials: M
authors.lastname: Morris
authors.forename: Anthony
authors.initials: A
authors.lastname: Kinsella
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Takei
authors.forename: Thomas
authors.initials: T
authors.lastname: McNeil
authors.forename: Dermot
authors.initials: D
authors.lastname: Walsh
authors.forename: Conall
authors.initials: C
authors.lastname: Larkin
mesh_terms: D000328:Adult; D000367:Age Factors; D015984:Causality; D005190:Family; D005260:Female; D006801:Humans; D038801:International Classification of Diseases; D007494:Ireland / Q000453:epidemiology; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology / Q000235:genetics; D015233:Models, Statistical; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011569:Psychiatric Status Rating Scales; D012042:Registries; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology; D012923:Social Class