Matthew Gallant said:
So:
1. Most mentally ill people never commit a violent crime.
2. The percentage of mentally ill in prison for violent crime is 2-3x higher than the general population.
No, the percentage of people with
severe mental disorders for
any crime was found
in one study to be 2-3x higher than the general population.
Matthew Gallant said:
A maximum of 15% of prisoners being seriously mentally ill compared to 5% out of prison (
http://www.nimh.nih.gov/statistics/SMI_AASR.shtml ) to me just means that the mentally ill aren't as good at getting away with it. But objectively, 85% of violent crimes cannot be explained in terms of mental illness. How could that possibly in any sense make mental illness a baseline factor?
Your inference that 85% of violent crimes cannot be explained in terms of mental illness is false. First, the study referenced did not focus on violent crimes, but just looked at a jail population in toto. Second, the study referenced is woefully inadequate for many reasons, not the least of which was its superficial methodolgy of detecting even what it described as "severe" mental disorders--administration of a single NIMH Diagnostic Interview Schedule. A competent and professional diagnostic assessment would require much more data and observation. This was a rough screening device from which the researchers attempted to identify the most obvious and apparent cases of mental illness.
Additionally, as I previously said, most incidence of mental illness and disorders by people who commit violent crimes goes completely undetected in trial (where it is often completely ignored--most crimes result in pleas and receive very little individual attention from lawyers and judges) and in subsequent incarceration (where mental health services to identify and treat mental disorders are severely inadequate and underfunded). Second, there is no reason to limit attention to "severe" mental illness. Mental disorders that cannot be classified as "severe" do play a substantial role in the commission of violent crime. It is important to understand this if we care to understand violent crime. And we should care to understand violent crime, because most believe it would be good to reduce it. The failure to understand the substantial connection between mental health and violent crime renders us unable to see how, e.g., providing universal and robust access to health care for all can have benefits to the society beyond its general health.
BobsRevenge said:
Its also important to note that commiting a violent crime can be part of a diagnoses for several illnesses, chiefly antisocial personality disorder. Since its part of a diagnoses its hard to separate out violent crime from some mental disorders, and that sort of messes with the statistics a bit. Violent individuals with antisocial personality disorder really ought to be in prison, imo. You can't really do too much there.
While it is true that the commission of crimes is a diagnostic criteria for ASPD, it is important to note that ASPD is very controversial within the psychiatric community. Also, ASPD isn't typically what we are referring to when we talk about mental illness/disorders being factors in crime. We are talking about things like bipolar disorder, post-traumatic stress disorder, mental retardation, depression, schizophrenia and other psychotic disorders, etc.
