Overt aggression and psychotic symptoms in patients with schizophrenia treated with clozapine, olanzapine, risperidone, or haloperidol

J Clin Psychopharmacol. 2004 Apr;24(2):225-8. doi: 10.1097/01.jcp.0000117424.05703.29.


The subjects were 157 treatment-resistant inpatients diagnosed with chronic schizophrenia or schizoaffective disorder. They were randomly assigned to treatment with clozapine, olanzapine, risperidone, or haloperidol in a 14-week, double-blind trial. Incidents of overt aggression were recorded and their severity was scored. The Positive and Negative Syndrome Scale was administered. Atypical antipsychotics showed an overall superiority over haloperidol, particularly after the first 24 days of the study when the dose escalation of clozapine was completed. Once an adequate therapeutic dose of clozapine was reached, it was superior to haloperidol in reducing the number and severity of aggressive incidents. Patients exhibiting persistent aggressive behavior showed less improvement of psychotic symptoms than the other patients. There was an interaction between aggressiveness, medication type, and antipsychotic response: risperidone and olanzapine showed better antipsychotic efficacy in patients exhibiting less aggressive behavior; the opposite was true for clozapine. Clozapine appears to have superior antiaggresive effects in treatment-resistant patients; this superiority develops after the patient has been exposed to an adequate dose regimen.

Publication types

  • Clinical Trial
  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Aggression / psychology*
  • Antipsychotic Agents / adverse effects
  • Antipsychotic Agents / therapeutic use*
  • Benzodiazepines / therapeutic use
  • Clozapine / therapeutic use
  • Double-Blind Method
  • Haloperidol / therapeutic use
  • Humans
  • Olanzapine
  • Psychiatric Status Rating Scales
  • Psychometrics
  • Psychotic Disorders / psychology*
  • Risperidone / therapeutic use
  • Schizophrenia / complications*
  • Schizophrenia / drug therapy*
  • Schizophrenic Psychology*


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