title: Validation of "prodromal" criteria to detect individuals at ultra high risk of psychosis: 2 year follow-up.
abstract: BACKGROUND
  Identification of individuals "prodromal" for schizophrenia and other psychotic disorders relies on criteria that predict onset within a brief period. Previous trials and biological research have been predicated on the view that certain "ultra high risk" (UHR) criteria detect "the prodrome", but there is a need to test the validity of these criteria.
  
  
  OBJECTIVE
  To assess the predictive validity of the UHR criteria in a clinical population.
  
  
  METHODS
  The presence of UHR criteria was determined in 292 help-seeking individuals. At 2 year follow-up the number of new cases of psychotic disorder was assessed.
  
  
  RESULTS
  The criteria significantly predicted onset of psychotic disorder within 2 years. The transition rate of 16% was much lower than in initial cohorts (over 40%).
  
  
  CONCLUSIONS
  The predictive validity of UHR criteria depends on the sample to which they are applied. Although young help-seekers meeting these criteria are at greater risk of psychotic disorder than those who do not meet them, caution is needed in their management, since a high transition rate can no longer be assumed.
authors.affiliation: Orygen Research Centre and University of Melbourne, Department of Psychiatry, Parkville 3052, Victoria, Australia. aryung@unimelb.edu.au
authors.forename: Alison R
authors.initials: AR
authors.lastname: Yung
authors.forename: Barnaby
authors.initials: B
authors.lastname: Nelson
authors.forename: Carrie
authors.initials: C
authors.lastname: Stanford
authors.forename: Magenta B
authors.initials: MB
authors.lastname: Simmons
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Cosgrave
authors.forename: Eoin
authors.initials: E
authors.lastname: Killackey
authors.forename: Lisa J
authors.initials: LJ
authors.lastname: Phillips
authors.forename: Andreas
authors.initials: A
authors.lastname: Bechdolf
authors.forename: Joe
authors.initials: J
authors.lastname: Buckby
authors.forename: Patrick D
authors.initials: PD
authors.lastname: McGorry