Significance of the positive-negative distinction in schizophrenia.

This article reviews the cumulative research on positive and negative syndromes in schizophrenia undertaken at the Albert Einstein College of Medicine. A strictly operationalized and standardized syndrome scale was applied in multidimensional, cross-sectional, prospective, longitudinal, phasic, and drug-free studies. The following conclusions about positive and negative syndromes were reached: they can be reliably assessed; they are normally distributed and theoretically independent, thus representing dimensions rather than coexclusive subtypes of schizophrenia; they differ in their association with premorbid functioning, family history of illness, cognitive profile, and neurological signs; their significance appears phase-specific, however, with ominous implications for a negative syndrome found only in the chronic stage; their magnitude is comparably high in all stages of the illness, challenging the view of a progressive negative state; they are stable under drug-free conditions and across months of drug therapy; they both improve with neuroleptics, with marginally better response for positive syndrome; worse long-range outcome is predicted by positive syndrome, especially by disorganized thinking, whereas worse short-term outcome is predicted by both syndromes; the positive-negative distinction, though valid, is incomplete as a model of schizophrenic phenomenology, which must include unrelated depressive and excited components; and Kraepelinian subtypes of schizophrenia seem to comprise not single pathological processes but a hybrid of unrelated, co-occurring syndromes.