title: The epidemiology of late-onset schizophrenia.
abstract: We report an analysis of a large catchment area sample of patients with nonaffective functional psychoses presenting across all ages at onset. The male:female ratio was 1.56:1 in the 16-25-year age group; it reached unity around 30 years of age and declined to 0.38:1 in the 66-75-year group. Contrary to expectation, a higher proportion of patients with onset of illness after 45 years than of younger onset patients fulfilled DSM-III-R criteria for schizophrenia (52% vs. 38%). The distribution by age at onset was much the same irrespective of stringency of diagnosis. The highest rates were in the 16-25-year age group, with a slight second peak in the 46-55-year group, and a third (more emphatic) peak in the over-65 group. A closer analysis of demographic and phenomenologic variables revealed distinct differences between patients with early and late (after 44 years) onset of illness.
authors.affiliation: Institute of Psychiatry, De Crespigny Park, London, United Kingdom.
authors.forename: D J
authors.initials: DJ
authors.lastname: Castle
authors.forename: R M
authors.initials: RM
authors.lastname: Murray
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003431:Cross-Cultural Comparison; D003430:Cross-Sectional Studies; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000175:diagnosis / Q000453:epidemiology*; D012565:Schizophrenic Psychology; D014481:United States / Q000453:epidemiology