The conclusions of those researching the putative link between schizophrenia and violence changed in the second half of the 20th century. Up until the early 1980s, the general consensus was that those with schizophrenia were no more likely than the general population to be violent. New epidemiological evidence has emerged, however, in recent years that has radically challenged this view. It is now generally accepted that people with schizophrenia, albeit by virtue of the activity of a small subgroup, are significantly more likely to be violent than members of the general population, but the proportion of societal violence attributable to this group is small. This chapter reviews the influential epidemiological studies in this area and provides an appraisal of the difficulties inherent in this type of research, with suggestions of how these might be overcome. We attempt to differentiate those most at risk of behaving violently and identify the likely victims of such acts. We conclude with some estimate of the absolute risk posed to the community by those with schizophrenia.

Review of studies investigating violent behaviour in schizophrenia

Three different approaches have been used to examine the association between schizophrenia and violence:

1 Studies estimating the prevalence of violent acts in those with schizophrenia

2 Studies estimating the prevalence of schizophrenia in individuals who have committed violent acts

3 Community-based epidemiological studies estimating the prevalence of violence in those with and without schizophrenia regardless of involvement with the mental health or criminal justice systems.