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

Psychiatr Serv. 2001 Nov;52(11):1510-4. doi: 10.1176/appi.ps.52.11.1510.


Objective: This study compared the specific antiaggressive effects of clozapine with those of olanzapine, risperidone, and haloperidol.

Methods: A total 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-week trial. The trial was divided into two periods: eight weeks during which the dosage was escalated and then fixed, and six weeks during which variable dosages were used. The hostility item of the Positive and Negative Syndrome Scale (PANSS) was the principal outcome measure. Covariates included the items that reflect positive symptoms of schizophrenia (delusions, suspiciousness or feelings of persecution, grandiosity, unusual thought content, conceptual disorganization, and hallucinations) and the sedation item of the Nurses Observation Scale for Inpatient Evaluation (NOSIE).

Results: Patients differed in their treatment response as measured by the hostility item of the PANSS. The scores of patients taking clozapine indicated significantly greater improvement than those of patients taking haloperidol or risperidone. The effect on hostility appeared to be independent of the antipsychotic effect of clozapine on other PANSS items that reflect delusional thinking, a formal thought disorder, or hallucinations and independent of sedation as measured by the NOSIE. Neither risperidone nor olanzapine showed superiority to haloperidol.

Conclusion: Clozapine has a relative advantage over other antipsychotics as a specific antihostility agent.

Publication types

  • Clinical Trial
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adult
  • Antipsychotic Agents / pharmacology*
  • Antipsychotic Agents / therapeutic use
  • Benzodiazepines
  • Clozapine / pharmacology
  • Clozapine / therapeutic use
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Emotions / drug effects
  • Female
  • Haloperidol / pharmacology
  • Haloperidol / therapeutic use
  • Hostility*
  • Humans
  • Linear Models
  • Male
  • Olanzapine
  • Pirenzepine / analogs & derivatives*
  • Pirenzepine / pharmacology
  • Pirenzepine / therapeutic use
  • Prospective Studies
  • Psychotic Disorders / drug therapy*
  • Psychotic Disorders / psychology
  • Risperidone / pharmacology
  • Risperidone / therapeutic use
  • Schizophrenia / drug therapy*
  • Schizophrenic Psychology
  • Statistics, Nonparametric
  • Survival Analysis


  • Antipsychotic Agents
  • Benzodiazepines
  • Pirenzepine
  • Clozapine
  • Haloperidol
  • Risperidone
  • Olanzapine