SYMPTOMS OF SCHIZOPHRENIA - METHODS, MEANINGS, AND MECHANISMS

Background: The ''group of schizophrenias,'' normally referred to with a single nominative, is phenomenologically heterogeneous. Its symptom s represent multiple psychological domains, including perception, infe rential thinking, language, attention, social interaction, emotion exp ression, and volition. Studies of psychopathology have simplified this complex array in several ways, one of which is a subdivision into pos itive and negative symptoms. Methods: This study examined the positive vs negative distinction in a sample of 243 patients with schizophreni a or schizophreniform disorder who were evaluated with the Scale for t he Assessment of Negative Symptoms and the Scale for the Assessment of Positive Symptoms. A two-stage factor analysis was applied, beginning with a principal components analysis applying varimax rotation, follo wed by an extension analysis. The purpose of these analyses was to eva luate the correlational relationships of the various symptoms of schiz ophrenia. Results: The results confirmed previous reports by our group and others suggesting that the symptoms of schizophrenia fall into th ree natural dimensions, as assessed by the correlational interrelation ships: positive symptoms subdivide into psychotic and disorganized dim ensions, while a third negative dimension also emerges. Conclusion: Be cause these dimensions have impressive consistency across studies, fut ure work must examine their relationship to clinically relevant concep ts such as prognosis or etiology and examine four different aspects: l ongitudinal course, neural mechanisms, relationship to treatment, and interrelationships in other pathological conditions.