Violence and phases of illness: differential risk and predictors.

This study tested the hypothesis that among patients with schizophrenia the risk and correlates of aggressive behavior differ depending on the level of positive symptoms. Two hundred and fifty-one adults with schizophrenia who were living in the community were assessed by psychiatrists using validated instruments. Patients and collaterals reported aggressive behavior. In a final multivariate model, aggressive behavior was significantly and positively associated with childhood conduct disorder, current use of illicit drugs, positive, threat-control-override (TCO), and depression symptoms. While 16% of the patients with two or fewer positive symptoms engaged in aggressive behavior in the previous six months, this was true of 28.4% of those with three or more positive symptoms (X2 (n=251,1)=5.48, P=0.019). Among patients with high positive symptoms, even univariate analyses failed to detect any factors associated with aggressive behavior other than medication non-compliance, typical antipsychotic medication, and clozapine. By contrast, among patients with few positive symptoms, aggressive behavior was associated with TCO and depression symptoms, young age, male sex, the number of childhood conduct disorder symptoms, prior aggressive behavior, and current illicit drug use. In phases of illness characterized by different levels of positive symptoms, the risk of aggressive behavior and the associated factors differ.