Late-onset schizophrenia and very-late-onset schizophrenia-like psychosis:An international consensus

Objective: Although schizophrenia is generally regarded as an illness with onset in late adolescence or early adult life, a sizeable minority of patie nts first become ill in middle or old age. Inconsistencies in diagnostic sy stems and nomenclature, coupled with a tendency among most schizophrenia re searchers to ascribe late-onset psychoses to organic factors, have led to s uch cases occupying an ambiguous position in relation to schizophrenia. Thr ough systematic review of the literature and publication of a consensus sta tement from an international group of experts in the field, this article ai ms to clarify the positions of late-onset schizophrenia and very-late-onset schizophrenia-like psychosis. Method: The authors conducted a MEDLINE lite rature review and developed a consensus statement summarizing the findings from 2 days of debate and discussion by members of the International Late-O nset Schizophrenia Group. Results: The group achieved consensus on diagnosi s, nomenclature, treatment guidelines, and future research directions. Conc lusions: In terms of epidemiology, symptom profile, and identified pathophy siologies, the diagnoses of late-onset schizophrenia (illness onset after 4 0 years of age) and very-late-onset schizophrenia-like psychosis (onset aft er 60 years) have face validity and clinical utility. General adoption of t hese categories will foster systematic investigation of such patients.