ABSTRACT
One of the most striking features of schizophrenia is its phenotypic heterogeneity. Schizophrenics differ so markedly among themselves in terms of their presenting clinical symptoms that the usefulness of the concept has been questioned for both clinical practice (e.g., Kanfer & Saslow, 1969) and research purposes (e.g., Bannister, 1968). One suggested alternative, going back to Bleuler (1911/1950), is to subdivide the schizophrenic population into more homogeneous subgroups. In addition to the traditional subtypes, schizophrenics have been divided into process versus reactive, paranoid versus nonparanoid, and most recently, positive versus negative subtypes. Since it is not yet clear whether these or any other divisions accurately “carve nature at its joints” (Meehl, 1979), viewing schizophrenia as an open scientific construct (Meehl, 1972; Neale & Oltmanns, 1980; Pap, 1958) remains a useful approach to the problem.
