Recent studies suggest that patients with psychotic illness alone have a modest increase in risk for violent behaviour, but the greatest risk is associated with personality disorder, substance abuse, say the authors. Variables such as male sex, young age, and lower socioeconomic status contribute a much higher proportion to societal violence than the modest amount attributable to mental illness.
If a person with mental illness is violent, however, it does not necessarily mean that this is due to the illness; it may be due to other coexisting risk variables, add the authors. Overall, it seems that less than 10% of serious violence, including homicide, is attributable to psychosis.
The evidence also contradicts the theory that the closing of large psychiatric institutions over the past 30 years have meant that a greater proportion of societal violence is attributable to those with mental disorder.
Fear and stigma of mentally ill people have been exaggerated by high profile and occasionally sensationalist reporting of rare, albeit tragic, violent acts. Yet the scientific literature refutes the stereotyping of all patients with severe mental illness as dangerous, say the authors. It is inappropriate that mental health policy and legislation should be driven by preoccupation with risk of violence, rather than the delivery of effective treatments in the community, they conclude.