[Clinical effects of clozapine: effect on negative symptoms]

we have realized an open study in a population of chronic schizophrenic inpatients treated with clozapine. The purpose of this study was to investigate the clinical response and the effect of extrapyramidal symptoms of this atypical antipsychotic.

our sample is composed of 25 chronic hospitalized schizophrenics (18 males, 7 females; average age = 36.57, SD = 8.41) with an initial important symptomatology (average score on BPRS = 64.92, SD = 7.99). The weekly assessment was done using PANSS and EPRS during 9 weeks. After a 15-days period of treatment adjustment, each patient reached a daily dose of 400 mg. Then the dosage was adjusted according to the clinical condition of the patients (average = 429.41 mg per day).

using the PANSS, we identified a statistically significant (p < 0.05) clinical improvement from the fourth week of treatment for global score, positive, negative and general psychopathology sub-score. For EPRS a dramatic improvement (p < 0.01) occurred from the second week. We found no correlation between the improvement of negative symptoms and the improvement of extrapyramidal symptoms. We individualized a sub-group of 7 good responders who showed an improvement of 20% or more on PANSS global score at the ninth week. This group showed a statistically significant (p < 0.01) more intense initial negative symptomatology compared to non-responders.

the improvement of extrapyramidal symptoms precede the improvement of psychotic symptoms; this effect underlines the good neurological tolerance of clozapine. The clinical efficacy concerns both positive and negative symptoms. The efficacy on negative symptoms seems to be primary. In our sample, patients with intense negative symptomatology improve more than others.