title: Late-onset schizophrenia and very-late-onset schizophrenia-like psychosis: an international consensus. The International Late-Onset Schizophrenia Group.
abstract: OBJECTIVE
  Although schizophrenia is generally regarded as an illness with onset in late adolescence or early adult life, a sizeable minority of patients first become ill in middle or old age. Inconsistencies in diagnostic systems and nomenclature, coupled with a tendency among most schizophrenia researchers to ascribe late-onset psychoses to organic factors, have led to such cases occupying an ambiguous position in relation to schizophrenia. Through systematic review of the literature and publication of a consensus statement from an international group of experts in the field, this article aims to clarify the positions of late-onset schizophrenia and very-late-onset schizophrenia-like psychosis.
  
  
  METHODS
  The authors conducted a MEDLINE literature review and developed a consensus statement summarizing the findings from 2 days of debate and discussion by members of the International Late-Onset Schizophrenia Group.
  
  
  RESULTS
  The group achieved consensus on diagnosis, nomenclature, treatment guidelines, and future research directions.
  
  
  CONCLUSIONS
  In terms of epidemiology, symptom profile, and identified pathophysiologies, the diagnoses of late-onset schizophrenia (illness onset after 40 years of age) and very-late-onset schizophrenia-like psychosis (onset after 60 years) have face validity and clinical utility. General adoption of these categories will foster systematic investigation of such patients.
authors.affiliation: International Late-Onset Schizophrenia Group, London, UK.
authors.forename: R
authors.initials: R
authors.lastname: Howard
authors.forename: P V
authors.initials: PV
authors.lastname: Rabins
authors.forename: M V
authors.initials: MV
authors.lastname: Seeman
authors.forename: D V
authors.initials: DV
authors.lastname: Jeste
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000368:Aged; D014150:Antipsychotic Agents / Q000627:therapeutic use; D001921:Brain / Q000000981:diagnostic imaging; D002648:Child; D002986:Clinical Trials as Topic; D005260:Female; D005544:Forecasting; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D017410:Practice Guidelines as Topic; D011859:Radiography; D011877:Radionuclide Imaging; D012107:Research Design / Q000639:trends; D012307:Risk Factors; D012559:Schizophrenia / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology*; D009626:Terminology as Topic; D016896:Treatment Outcome
chemical_list: D014150:Antipsychotic Agents