title: Acute and transient psychotic disorders: precursors, epidemiology, course and outcome.
abstract: BACKGROUND
  ICD-10 has introduced the diagnostic group acute and transient psychotic disorders (ATPDs; F23).
  
  
  OBJECTIVE
  To validate the nosological distinctiveness of ICD-10 ATPDs by following up an inception cohort with first-episode psychosis.
  
  
  METHODS
  All patients with first-episode psychosis identified in Nottingham between 1992 and 1994 and diagnosed using ICD-10 criteria were reassessed 3 years later. ATPD outcomes were compared with schizophrenia and affective psychosis. Multivariate analyses were conducted to determine whether acute onset and early remission predicted favourable 3-year outcome in first-episode psychosis.
  
  
  RESULTS
  Of 168 cases of first-episode psychosis, 32 (19%) received an intake diagnosis of ATPD. The diagnosis of ATPD was stable in women over 3 years, but not in men. Outcomes in ATPD were better than in schizophrenia and similar to affective psychosis. In non-affective psychoses, favourable outcomes were a function of gender and premorbid functioning rather than acute onset and early remission.
  
  
  CONCLUSIONS
  The ICD-10 criteria for ATPDs identify a diagnostically unstable group of disorders. Acute onset and early remission do not independently predict favourable outcome over 3 years in first-episode psychosis.
authors.affiliation: Department of Mental Health, Jenner Wing, St George's Hospital Medical School, London SW17 0RE, UK. s.singh@sghms.ac.ac.uk
authors.forename: Swaran P
authors.initials: SP
authors.lastname: Singh
authors.forename: Tom
authors.initials: T
authors.lastname: Burns
authors.forename: Shazad
authors.initials: S
authors.lastname: Amin
authors.forename: Peter B
authors.initials: PB
authors.lastname: Jones
authors.forename: Glynn
authors.initials: G
authors.lastname: Harrison
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D006801:Humans; D008016:Life Change Events; D008875:Middle Aged; D015999:Multivariate Analysis; D010375:Pedigree; D011379:Prognosis; D011618:Psychotic Disorders / Q000175:diagnosis* / Q000453:epidemiology / Q000235:genetics