title: Beyond the critical period: longitudinal study of 8-year outcome in first-episode non-affective psychosis.
abstract: BACKGROUND
  The critical period hypothesis proposes that deterioration occurs aggressively during the early years of psychosis, with relative stability subsequently. Thus, interventions that shorten the duration of untreated psychosis (DUP) and arrest early deterioration may have long-term benefits.
  
  
  OBJECTIVE
  To test the critical period hypothesis by determining whether outcome in non-affective psychosis stabilises beyond the critical period and whether DUP correlates with 8-year outcome; to determine whether duration of untreated illness (DUI) has any independent effect on outcome.
  
  
  METHODS
  We recruited 118 people consecutively referred with first-episode psychosis to a prospective, naturalistic cohort study.
  
  
  RESULTS
  Negative and disorganised symptoms improved between 4 and 8 years. Duration of untreated psychosis predicted remission, positive symptoms and social functioning at 8 years. Continuing functional recovery between 4 and 8 years was predicted by DUI.
  
  
  CONCLUSIONS
  These results provide qualified support for the critical period hypothesis. The critical period could be extended to include the prodrome as well as early psychosis.
authors.affiliation: Stanley Research Unit, Cluain Mhuire Family Centre, St John of God Adult Psychiatric Service, Dublin, Ireland.
authors.forename: Niall
authors.initials: N
authors.lastname: Crumlish
authors.forename: Peter
authors.initials: P
authors.lastname: Whitty
authors.forename: Mary
authors.initials: M
authors.lastname: Clarke
authors.forename: Stephen
authors.initials: S
authors.lastname: Browne
authors.forename: Moayyad
authors.initials: M
authors.lastname: Kamali
authors.forename: Maurice
authors.initials: M
authors.lastname: Gervin
authors.forename: Orfhlaith
authors.initials: O
authors.lastname: McTigue
authors.forename: Anthony
authors.initials: A
authors.lastname: Kinsella
authors.forename: John L
authors.initials: JL
authors.lastname: Waddington
authors.forename: Conall
authors.initials: C
authors.lastname: Larkin
authors.forename: Eadbhard
authors.initials: E
authors.lastname: O'Callaghan
mesh_terms: D000293:Adolescent; D000328:Adult; D000341:Affective Disorders, Psychotic / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003423:Critical Period, Psychological; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007494:Ireland / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000175:diagnosis / Q000523:psychology / Q000628:therapy*; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult