title: Health service registry data in psychiatric epidemiology: challenges for definition and interpretation: an editorial comment to: Okkels et al.'s 'changes in the diagnosed incidence of early onset schizophrenia over four decades' (1).
authors.forename: Kelly K
authors.initials: KK
authors.lastname: Anderson
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D012042:Registries / Q000706:statistics & numerical data*; D012559:Schizophrenia / Q000453:epidemiology*