Clinical outcome to clozapine treatment in chronic psychiatric inpatients.

1. A review of the medical records in a state psychiatric hospital was conducted to evaluate the clinical efficacy of the atypical antipsychotic, clozapine. 2. Using the Brief Psychiatric Rating Scale (BPRS), four groups of schizophrenic inpatients (n = 59) were operationally defined: Nonresponders (< 20% decrease from pre-drug baseline); Short-term Pharmacological Responders (20% decline, but not sustained); Long-term Pharmacological Responders (maintained a 20% decline) and Clinical Responders (maintained a 20% decline and achieved a BPRS < or = 36; the criterion of Kane et al. 1988). 3. There were 7 NRs, 13 STPRs, 21 LTPRs and 18 CRs 4. The STPR, LTPR and CR groups improved significantly within the first month of treatment and reached a 20% decrease in BPRS by 3 months. CRs required 5 months to attain a BPRS < or = 36. These criteria were reached at the same average doses (about 300-400 mg/day). 5. The proportion of CRs (30%) in this retrospective, naturalistic study, is remarkably close to the results of the definitive study by Kane et al. 1988. These results are also consistent with many of the controlled research studies of clozapine in hospitalized, treatment refractory psychiatric patients.