The association between psychotic symptoms and violence is unclear, due in part to methodological features of investigations that have examined this question, and in part to the fact that the association likely differs by disorder and treatment conditions. Using data from The Comparative Study of the Prevention of Crime and Violence by Mentally Ill Persons, we examined 128 men with schizophrenia or schizoaffective disorder discharged from general and forensic psychiatric hospitals in Canada, Finland, Germany, and Sweden. The association between symptoms and aggressive behavior was studied during two 6 month periods when the patients lived in the community. Severe positive and negative symptoms of psychosis, depression, and anxiety were measured at the beginning of each of the 6 month periods. In addition, at the beginning of the second 6 month period changes in symptoms in the previous period were indexed. Aggressive behavior was measured in each 6 month period by reports from patients and from collaterals. During the first 6 months post-discharge, after controlling for the presence of antisocial personality disorder or PCL score and past diagnoses of alcohol/drug abuse/dependence, the presence of a severe positive symptom significantly increased the risk of aggressive behavior. During the second 6 month period, after controlling for antisocial personality disorder or PCL score and self-reported alcohol/drug use, the presence of a severe positive symptom, a TCO symptom, and an increase in TCO symptoms significantly increased the risk of aggressive behavior. Neither depot medications nor obligatory community treatment reduced the risk of aggressive behavior after controlling for the presence of a severe positive symptom and/or TCO symptoms. These findings suggest that, among men with schizophrenia being treated in the community, the presence of severe psychotic symptoms and the development of TCO symptoms are antecedents of aggressive behavior.
Copyright 2003 John Wiley & Sons, Ltd.