title: Prediction of psychosis in adolescents and young adults at high risk: results from the prospective European prediction of psychosis study.
abstract: BACKGROUND
  Indicated prevention is currently regarded as the most promising strategy to attenuate, delay, or even avert psychosis. Existing criteria need improvement in terms of specificity and individual risk assessment to allow for better targeted and earlier interventions.
  
  
  OBJECTIVE
  To develop a differential predictive clinical model of transition to first-episode psychosis.
  
  
  METHODS
  Prospective multicenter, naturalistic field study with a total follow-up time of 18 months.
  
  
  METHODS
  Six early-detection outpatient centers in Germany, Finland, the Netherlands, and England.
  
  
  METHODS
  Two hundred forty-five help-seeking patients in a putatively prodromal state of psychosis according to either ultra-high-risk (UHR) criteria or the basic symptom-based criterion cognitive disturbances (COGDIS).
  
  
  METHODS
  Incidence of transition to psychosis.
  
  
  RESULTS
  At 18-month follow-up, the incidence rate for transition to psychosis was 19%. Combining UHR and COGDIS yielded the best sensitivity. A prediction model was developed and included positive symptoms, bizarre thinking, sleep disturbances, a schizotypal disorder, level of functioning in the past year, and years of education. With a positive likelihood ratio of 19.9, an area under the curve of 80.8%, and a positive predictive value of 83.3%, diagnostic accuracy was excellent. A 4-level prognostic index further classifying the general risk of the whole sample predicted instantaneous incidence rates of up to 85% and allowed for an estimation of time to transition.
  
  
  CONCLUSIONS
  The prediction model identified an increased risk of psychosis with appropriate prognostic accuracy in our sample. A 2-step risk assessment is proposed, with UHR and cognitive disturbance criteria serving as first-step criteria for general risk and the prognostic index as a second-step tool for further risk classification of each patient. This strategy will allow clinicians to target preventive measures and will support efforts to unveil the biological and environmental mechanisms underlying progression to psychosis.
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Cologne, Kerpener Strasse 62, 50924 Cologne, Germany. stephan.ruhrmann@uk-koeln.de
authors.forename: Stephan
authors.initials: S
authors.lastname: Ruhrmann
authors.forename: Frauke
authors.initials: F
authors.lastname: Schultze-Lutter
authors.forename: Raimo K R
authors.initials: RK
authors.lastname: Salokangas
authors.forename: Markus
authors.initials: M
authors.lastname: Heinimaa
authors.forename: Don
authors.initials: D
authors.lastname: Linszen
authors.forename: Peter
authors.initials: P
authors.lastname: Dingemans
authors.forename: Max
authors.initials: M
authors.lastname: Birchwood
authors.forename: Paul
authors.initials: P
authors.lastname: Patterson
authors.forename: Georg
authors.initials: G
authors.lastname: Juckel
authors.forename: Andreas
authors.initials: A
authors.lastname: Heinz
authors.forename: Anthony
authors.initials: A
authors.lastname: Morrison
authors.forename: Shôn
authors.initials: S
authors.lastname: Lewis
authors.forename: Heinrich Graf
authors.initials: HG
authors.lastname: von Reventlow
authors.forename: Joachim
authors.initials: J
authors.lastname: Klosterkötter
mesh_terms: D000328:Adult; D000553:Ambulatory Care; D018450:Disease Progression; D042241:Early Diagnosis; D005060:Europe / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008137:Longitudinal Studies; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000517:prevention & control; D018570:Risk Assessment; D012307:Risk Factors; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology; D055815:Young Adult