Certainly the evidence is clear that people with mental health problems are not more violent than the general population in general. It is important to remember that, because while we are talking about great need in the correctional system for services for people with mental illness and addiction problems, I think that saying they are there because of those problems is a dangerous way to go. Then we conflate two things.
On this question, I think we really have to separate mental illness and substance use. Many people are in the correctional system because of their substance use, which may or may not be an addiction issue. We know that alcohol is implicated in many crimes in the sense that violence tends to result from alcohol. Alcohol causes huge social problems, which is one of the reasons the CAMH does a lot of work on alcohol policy and lowering blood alcohol levels and those kinds of things.
We know that there is a great connection between alcohol, violence, and people being in correctional facilities. There are other people who are there because of the consequence of their drug use. So it may not be a violence issue. It tends to be people on harder drugs, who have stolen to support those habits. They're not as prevalent as alcohol-related problems. When it comes to mental illness, I would not say that mental illness causes people to be criminal.