title: Duration of untreated psychosis: Impact of the definition of treatment onset on its predictive value over three years of treatment.
abstract: BACKGROUND
  While reduction of DUP (Duration of Untreated Psychosis) is a key goal in early intervention strategies, the predictive value of DUP on outcome has been questioned. We planned this study in order to explore the impact of three different definition of "treatment initiation" on the predictive value of DUP on outcome in an early psychosis sample.
  
  
  METHODS
  221 early psychosis patients aged 18-35 were followed-up prospectively over 36 months. DUP was measured using three definitions for treatment onset: Initiation of antipsychotic medication (DUP1); engagement in a specialized programme (DUP2) and combination of engagement in a specialized programme and adherence to medication (DUP3).
  
  
  RESULTS
  10% of patients never reached criteria for DUP3 and therefore were never adequately treated over the 36-month period of care. While DUP1 and DUP2 had a limited predictive value on outcome, DUP3, based on a more restrictive definition for treatment onset, was a better predictor of positive and negative symptoms, as well as functional outcome at 12, 24 and 36 months. Globally, DUP3 explained 2 to 5 times more of the variance than DUP1 and DUP2, with effect sizes falling in the medium range according to Cohen.
  
  
  CONCLUSIONS
  The limited predictive value of DUP on outcome in previous studies may be linked to problems of definitions that do not take adherence to treatment into account. While they need replication, our results suggest effort to reduce DUP should continue and aim both at early detection and development of engagement strategies.
authors.affiliation: Service of General Psychiatry, Treatment and Early Intervention in Psychosis Program (TIPP-Lausanne), Lausanne University Hospital (CHUV), Switzerland; Service of Community Psychiatry, Department of Psychiatry, Lausanne University Hospital (CHUV), Switzerland. Electronic address: Philippe.Golay@chuv.ch.
authors.forename: Philippe
authors.initials: P
authors.lastname: Golay
authors.affiliation: Service of General Psychiatry, Treatment and Early Intervention in Psychosis Program (TIPP-Lausanne), Lausanne University Hospital (CHUV), Switzerland; Unit for Research in Schizophrenia, Center for Psychiatric Neuroscience, Lausanne University Hospital (CHUV), Switzerland.
authors.forename: Luis
authors.initials: L
authors.lastname: Alameda
authors.affiliation: Service of General Psychiatry, Treatment and Early Intervention in Psychosis Program (TIPP-Lausanne), Lausanne University Hospital (CHUV), Switzerland; Unit for Research in Schizophrenia, Center for Psychiatric Neuroscience, Lausanne University Hospital (CHUV), Switzerland.
authors.forename: Philipp
authors.initials: P
authors.lastname: Baumann
authors.affiliation: Mobile Psychiatry Unit, Department of Psychiatry, Prangins Psychiatric Hospital (CHUV), Switzerland.
authors.forename: Julien
authors.initials: J
authors.lastname: Elowe
authors.affiliation: Service of General Psychiatry, Treatment and Early Intervention in Psychosis Program (TIPP-Lausanne), Lausanne University Hospital (CHUV), Switzerland.
authors.forename: Pierre
authors.initials: P
authors.lastname: Progin
authors.affiliation: Orygen Youth Health Clinical Program, Centre for Youth Mental Health, University of Melbourne, Australia.
authors.forename: Andrea
authors.initials: A
authors.lastname: Polari
authors.affiliation: Service of General Psychiatry, Treatment and Early Intervention in Psychosis Program (TIPP-Lausanne), Lausanne University Hospital (CHUV), Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Conus
mesh_terms: D000293:Adolescent; D000328:Adult; D014150:Antipsychotic Agents / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D055118:Medication Adherence; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000453:epidemiology* / Q000523:psychology / Q000628:therapy*; D012559:Schizophrenia / Q000453:epidemiology / Q000628:therapy; D012565:Schizophrenic Psychology; D061665:Time-to-Treatment; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D014150:Antipsychotic Agents
keywords: Duration of untreated psychosis; Early psychosis; First episode psychosis; Treatment adherence