Schizophrenia, Violence, Clozapine and Risperidone: a Review

There is no longer much doubt that there is a small but real association between psychosis and violence directed at others, as well as between psychosis and self-directed violence, including suicide. Schizophrenia and the affective psychoses appear to have a similar order of association with suicide (Caldwell & Gottesman, 1990), but schizophrenia is more likely to be associated with serious other-directed violence. The evidence for the effect of schizophrenia comes from three main directions. There are two substantial cross-sectional USA community studies (Swanson et al, 1990; Link et al, 1992), respectively showing a significant quantitative association between schizophrenia and violence. Comparative studies of illness and offending careers (Lindqvist & Allebeck, 1990; Hodgins, 1992; Coid et al, 1993; Taylor, 1993; Wessely et al, 1994), all show different patterns of violent offending by people with schizophrenia compared with those without a psychotic illness, the 1993 studies confirming that the onset of violence is almost invariably after the onset of illness. The third type of evidence is from phenomenology. Taylor (1985) and Link & Stueve (1994) have shown a strong association between delusions and serious violence, the former demonstrating a specific effect of acting on delusions. (For a more extended discussion see Taylor, 1995.)