The Problem of Diagnostic Criteria in the Study of the Paranoid Subclassification of Schizophrenia*

In describing the history of the diagnostic terms "paranoid" and "paranoia," Lewis (1970) summarized the last half of the 19th century in the following manner: " . . . the words [paranoid and paranoia] and the concept they denoted were given so many shades of meaning that, although the delusional core was always there, the diagnostic implication varied enormously, and there was general discontent" (p. 4). Nearly the same passage has been used to describe recent conditions: "Adequate studies of the interrelationship among the descriptive dimensions [of schizophrenia] have been retarded and confounded . . . by variations in the operational definition of measures" (Eisenthal, Harford, and Solomon 1972, p. 227). Since Kraepelin, subtypes of schizophrenia have emerged and gained various degrees of popularity only to be invalidated by subsequent experience or research. In contrast, the paranoid subclassification has endured and, indeed, has been given increased emphasis by contemporary research. Silverman (1964), Goldstein, Held, and Cromwell (1968), and Tsuang and Winokur (1974), among others, have concluded that the paranoid form is an important distinguishing subtype in schizophrenia.