A prospective study of clozapine in treatment-resistant schizophrenic patients. I. Preliminary report.

Preliminary results of a non-blinded prospective study of the effect of clozapine on symptomatology and social function in 51 treatment-resistant schizophrenic patients are reported. The mean duration of treatment at the time of this report was 10.3 +/- 8.1 months, median 7.6 months. Overall, 3/51 patients (60.8%) showed at least a 20% decrease in total BPRS, a criterion of improvement in the study of Kane et al. (1988). Four of 51 (7.8%) had at least a 50% decrease in total BPRS. Improvements in both positive and negative symptoms were noted. Marked improvements in social function were noted within the first 6 months of treatment. Improvement was first noted at all time points, with only 45.2% of improvers being identified after 6 weeks of treatment. These results suggest a 6-12-month trial may be desirable before deciding to discontinue clozapine because of insufficient response. Higher total Brief Psychiatric Rating Scale (BPRS) score and higher ratings on the Paranoid Disturbance subscales of the BPRS were factors which discriminated clozapine responders from non-responders.