Dose related response to clozapine in a state psychiatric hospital population: a naturalistic study.

After noting a striking difference in the dosing practices of two treating psychiatrists, each responsible for the operation of a clozapine unit in a state psychiatric hospital, the authors conducted a retrospective chart review to assess the clinical efficacy of low dose x = 294 mg. per day) versus high dose (x = 525 mg. per day) clozapine treatment for a cohort of 31 inpatients. Levels of psychopathology, behavior, and social functioning were assessed six months pre and during clozapine treatment for 16 patients who received low dose clozapine treatment and 15 patients who received high dose clozapine treatment. Patients on both units demonstrated significant reductions in their levels of psychopathology, improved social functioning and improvement in their behavior following six months clozapine treatment. This naturalistic study suggests that the use of low dose clozapine provides effective treatment for chronic, severely treatment resistant inpatients with schizophrenia or schizo-affective illness, at the same time reducing the potential for significant side effects.