I'm not aware of any psychological studies that have been done. I know we have worked with the mental illness associations both in Canada and the United States. In fact, we were endorsed by the national schizophrenic group within British Columbia several years ago as being a good tool to have available to police, again, as another tool in the tool box. But there are no peer-reviewed published studies that I'm aware of on psychological effects.
On January 30th, 2008. See this statement in context.