Schizophrenia and violence

The relationship between schizophrenia and violence is studied from a psychiatric and a public health perspective.

All epidemiological studies which have been published since 1990 are reviewed.

Despite differences in the methodological approaches chosen the studies reviewed concur in supporting the assumption that there is a moderate but significant association between schizophrenia (or more generally psychotic disorders) and violence. However, compared with the magnitude of risk associated with substance abuse and personality disorders, that associated with schizophrenia or other major mental disorders is small. In addition, the elevated risk to behave violently appears to be limited to particular symptom constellations. The evidence available so far suggests that the proportion of violent crimes committed by people suffering from a severe mental disorder is small. There is no unambiguous evidence of an increase of violent acts committed by severely mentally ill people in general and people suffering from schizophrenia in particular during recent years. Strangers appear to be at an even lower risk of being violently attacked by someone suffering from severe mental disorder than by someone who is mentally healthy.

While the assessment of relative risk is of great interest for psychiatric researchers who are trying to identify factors which may increase or decrease the risk of violent behaviour among the mentally ill, which in turn may provide some clues as to how to intervene best in order to reduce the risk, the attributable risk is of special interest for the public since it informs about the risk of becoming victim of a violent act committed by someone who is suffering from a mental disorder.