Comparative evaluation of research diagnostic criteria for schizophrenia.

Criteria for establishing a diagnosis of schizophrenia have been proposed by several different authors. This study compared six different research diagnostic criteria (RDC) in a series of 166 patients who received a clinical diagnosis of schizophrenia in a multicenter study. The alternative criteria differed in the proportion of clinical diagnoses that were confirmed, with the Washington University (Feighner) criteria accepting only 26%. The criteria also disagreed concerning which particular patients qualified for the diagnosis. The Washington University and New York RDC disagreed 50% of the time, and some other disagreement rates were even higher. More evaluative research is needed before arbitrary criteria are permitted to redefine the concept of schizophrenia.