Some methodological considerations for the clinical evaluation of neuroleptics--comparative effects of clozapine and haloperidol on schizophrenics

Abstract

For the purpose of evaluating objectively the characteristics of clinical effects of clozapine and haloperidol, a double-blind comparative trial was conducted on 91 schizophrenic in-patients. The changes of symptoms were assessed by means of several psychiatric and behavioral rating scales. The results were analyzed by means of nonparametric statistical methods. Furthermore, application of multivariate analysis was considered. After 12 weeks of treatment, though no significant difference in general improvement rate was noted between the two groups, a marked different spectrum of clinical effects was observed according to the rating scales. Clozapine is superior in anti-delusional, contact-promoting and sedative anxiolytic effect, while haloperidol is superior in anti-autistic effect. Among the side-effects, extrapyramidal symptoms appeared significatly more severe in the haloperidol group. The frequency of appearance of fever, was significantly greater in the clozapine group than the other. The four dropout cases of the clozapine group were all caused by fever. Through this clinical trial, clinical availability and validity of various statistical analytical methods were reconsidered.