Overt Aggression and Psychotic Symptoms in Patients with Schizophrenia Treated with Clozapine, Olanzapine, Risperidone, or Haloperidol

Jan Volavka, Pal Czobor, Karen Nolan, Brian Sheitman, Jean Pierre Lindenmayer, Leslie Citrome, Joseph P. McEvoy, Thomas B. Cooper, Jeffrey A. Lieberman

Research output: Contribution to journalArticle

138 Scopus citations


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.

Original languageEnglish (US)
Pages (from-to)225-228
Number of pages4
JournalJournal of Clinical Psychopharmacology
Issue number2
Publication statusPublished - Apr 1 2004
Externally publishedYes


ASJC Scopus subject areas

  • Psychiatry and Mental health
  • Pharmacology (medical)

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