Effects of clozapine, olanzapine, risperidone, and haloperidol on hostility among patients with schizophrenia

Objective: This study, compared the specific antiaggressive effects of cloz apine with those of olanzapine, risperidone, and haloperidol. Methods: A to tal of 157 inpatients with schizophrenia or schizoaffective disorder and a history, of suboptimal treatment response were randomly assigned to receive clozapine, olanzapine, risperidone, or haloperidol in a double-blind 14-we ek trial. The trial was divided into two periods: eight weeks during which the dosage was escalated and then fixed, and six weeks during which variabl e dosages were used. The hostility, item of the Positive and Negative Syndr ome Scale (PANSS) was the principal outcome measure. Covariates included th e items that reflect positive symptoms of schizophrenia (delusions, suspici ousness or feelings of persecution, grandiosity, unusual thought content, c onceptual disorganization, and hallucinations) and the sedation item of the Nurses Observation Scale for Inpatient Evaluation (NOSIE). Results: Patien ts differed in their treatment response as measured by the hostility, item of the PANSS. The scores of patients taking clozapine indicated significant ly, greater improvement than those of patients taking haloperidol or risper idone. The effect on hostility appeared to be independent of the antipsycho tic effect of clozapine on other PANSS items that reflect delusional thinki ng, a formal thought disorder, or hallucinations and independent of sedatio n as measured by the NOSIE. Neither risperidone nor olanzapine showed super iority, to haloperidol. Conclusion: Clozapine has a relative advantage over other antipsychotics as a specific anti-hostility agent.