The authors describe the results of a blind rediagnosis, with DSM-III
criteria, of psychotic siblings who were originally diagnosed as
schizophrenic when reported by Zehnder in 1940. The distribution in sibling
pairs of patients meeting criteria for affective illness and schizophrenia
differed significantly from chance expectation, suggesting that, from a
familial perspective, the two disorders were not closely related. However,
the distribution of patients diagnosed as having schizoaffective disorder
resembled that found for schizophrenia and not affective illness. Using
several sets of diagnostic criteria, the authors found a moderate degree of
familial independence for paranoid and nonparanoid schizophrenia.Abstract Teaser