Negative v Positive Schizophrenia

TLDR

Schizophrenia can be divided into positive, negative, and mixed subtypes, distinguished by delusions, hallucinations, affective flattening, alogia, avolition, anhedonia, and attentional impairment, with mixed cases showing either or neither symptom set. The study aimed to develop criteria for classifying schizophrenia into positive, negative, and mixed subtypes. The authors examined the validity of these criteria through multiple analyses. The subtypes differed significantly on premorbid adjustment, cognitive dysfunction, ventricular brain ratio, and hospitalization course, and symptom correlations further supported the subtyping.

Abstract

• We developed criteria for dividing the schizophrenic syndrome into three subtypes: positive, negative, and mixed schizophrenia. Positive schizophrenia is characterized by prominent delusions, hallucinations, positive formal thought disorder, and persistently bizarre behavior; negative schizophrenia, by affective flattening, alogia, avolition, anhedonia, and attentional impairment. In mixed schizophrenia either<i>both</i>negative and positive symptoms are prominent, or<i>neither</i>is prominent. We explored the validity of these criteria in a variety of ways. Significant differences between the three types were noted using external validators such as premorbid adjustment, indices of cognitive dysfunction, ventricular brain ratio, and course in hospital. The correlational structure of the symptom complexes also provided further support for our approach to subtyping.