title: Obstetric complications and transition to psychosis in an "ultra" high risk sample.
abstract: OBJECTIVE
  An association between birth and pregnancy complications and the later development of schizophrenia has been described for decades and obstetric complications (OCs) have been proposed as a vulnerability marker for psychosis in line with the neurodevelopmental hypothesis of psychotic disorders. Previous studies of OCs have focused on established schizophrenia. In this study, the association between OCs and the development of psychotic disorder was studied in a group of 74 young people identified as being at very high risk for the first onset of psychosis.
  
  
  METHODS
  The "ultra" high risk (UHR) cohort was identified by the presence of subthreshold psychotic symptoms, or a combination of first-degree relative with a psychotic disorder and recent functional decline. Thirty-eight per cent of the cohort developed an acute psychotic episode over the 12-month period after recruitment. As a component of a larger research study, the level of OCs experienced by the UHR cohort was assessed at intake.
  
  
  RESULTS
  Obstetric complications were not associated with the later development of psychosis in the UHR group included in this study.
  
  
  CONCLUSIONS
  This study does not support a role for OCs as a risk factor for the later development of psychosis; however, we cannot conclude that they should be completely ignored as a candidate risk factor for onset of psychosis. A number of weaknesses of the study suggest that it may be premature to dismiss OCs as a risk factor for the development of psychosis and further research is urged in this area.
authors.affiliation: Mental Health Center, West China Hospital, Sichuan University, 7 Xiaoxue Road, Chengdu, Sichuan Province 610044, China. yunyang100@hotmail.com
authors.forename: Yang
authors.initials: Y
authors.lastname: Yun
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Phillips
authors.forename: Sue
authors.initials: S
authors.lastname: Cotton
authors.forename: Alison R
authors.initials: AR
authors.lastname: Yung
authors.forename: Shona M
authors.initials: SM
authors.lastname: Francey
authors.forename: Hok Pan
authors.initials: HP
authors.lastname: Yuen
authors.forename: Patrick D
authors.initials: PD
authors.lastname: McGorry
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D007744:Obstetric Labor Complications / Q000453:epidemiology; D049590:Postpartum Period / Q000523:psychology*; D011247:Pregnancy; D011618:Psychotic Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology*; D012307:Risk Factors; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology / Q000209:etiology; D012720:Severity of Illness Index