RESUMEN
OBJECTIVE: The purpose of this study was to identify the predictors of one-year clozapine treatment in refractory schizophrenic patients. METHODS: We defined treatment response as the reduction of total PANSS scores by 20% or more and as the total PANSS scores below 60, or as the CGI severity score below 3, after one-year of clozapine treatment. We compared age, duration of illness, number of hospitalization, plasma monoamine metabolites, ventricle-brain ratio, and short-term treatment response between treatment response group and treatment non-response group. RESULTS: Among the total patients of 26, 12(46%) were categorized as treatment response group. In comparing between treatment response group(N=12) and treatment non-response group (N=14), there were no differences in age, onset age, duration of illness, but the number of hospitalization was significantly more frequent in treatment non-response group. There was no significant difference in total PANSS scores between the two groups before clozapine treatment. After 4 weeks of clozapine treatment, the changes of PANSS positive score was more higher in treatment response group. The baseline plasma HVA levels and HVA/5-HIAA ratio were significantly higher in treatment response group than in non-response group, but there was no significant difference in baseline plasma 5-HIAA levels between the two groups. No difference existed in ventricle-brain ratio between the two groups. CONCLUSION: This study suggests that number of hospitalization and short-term treatment response rate may be useful as the clinical predictors, and that plasma HVA levels also as a biological predictor of long term clozapine treatment.