The authors examined the reliability, frequency, concordance, and
demographic characteristics of subtypes of schizophrenia in patients from
the Iowa 500 study as defined by four major diagnostic systems: DSM-III,
Research Diagnostic Criteria (RDC), ICD-9, and the Tsuang- Winokur
criteria. Reliability was higher in diagnostic systems with operationalized
than in those with unoperationalized criteria and consistently higher for
the paranoid subtype. The frequency of individual subtypes varied widely
for the different systems. Concordance for subtype diagnoses between
systems ranged from quite high to quite low. Demographic characteristics of
the individual subtypes were similar according to all systems.Abstract Teaser