A randomized trial comparing clozapine and typical neuroleptic drugs in non-treatment-resistant schizophrenia

Clozapine has been shown to be superior to typical neuroleptic drugs for treating positive symptoms in treatment-resistant (TR) schizophrenia. Long-term data from randomized clinical trials comparing clozapine with typical neuroleptics in non-TR schizophrenia are rare. We previously reported that clozapine was superior to typical neuroleptic drugs in some domains of cognition in recent onset non-TR schizophrenia. We now present data on psychopathology and quality of life from this randomized, flexibly dosed, 24-month study of clozapine vs. typical neuroleptics in non-TR schizophrenia patients. Both treatments produced significant improvement in measures of psychopathology, quality of life, and global function, with minor exceptions. There was no difference in extrapyramidal side effects between the patients treated with clozapine or typical neuroleptics. However, significantly more relapse/rehospitalization drop-outs occurred in the typical neuroleptic group. Two patients treated with typical neuroleptics, but none treated with clozapine, became non-responsive to treatment. Clozapine was associated with significantly greater weight gain. Clozapine and typical neuroleptic drugs appear to produce equivalent improvement in psychopathology in patients with non-TR schizophrenia. Clozapine may be more effective than typical neuroleptics for treatment retention and prevention of relapse, but it produces more severe metabolic side effects. These considerations should be taken into account in decisions of how best to utilize clozapine in the treatment of schizophrenia.