Stability of psychopathology dimensions in chronic schizophrenia: response to clozapine treatment.

Current models of schizophrenia postulate that different symptom complexes, including the positive and negative, may relate to fundamental underlying neurobiological distinctions. However, the premise of an underlying stability to the psychopathological profile has not been systematically investigated, particularly in response to pharmacological intervention. The present work aimed to study this issue in 14 chronic schizophrenic inpatients by comparing their symptom clusters before and after a 20-week course of clozapine treatment. The results indicated significant improvement on all eight symptom dimensions, as well as in severity of general psychopathology. Despite the clinical gains, most dimensions remained highly stable, with correlations between prestudy and clozapine week 20 ranging up to .91 (P less than .0001) for the positive-negative composite score. These findings of stability over time, even in response to potent treatment, support the validity and importance of schizophrenic psychopathology dimensions, which appeared to possess fundamental traitlike characteristics.