It's worth mentioning that there's some evidence (and a brouhaha over those who are trying to publish about it) that the chief measure of psychopathy - the PCL - merely measures recidivism. Could it be that a "psychopath" is simply a recidivist or does this just beg the question?

Practically the only accurate depiction of mental illness (autism) was that of Dustin Hoffman in Rainman. It got him an Oscar.

Most actors inaccurately depict mental illness by acting silly. Mania cannot be physically duplicated by any human being (loud rapid speech, infectious jocularity, sleeplessness without fatigue). The real sociopath can be charming, and criminals have above average social skills. For example, the defendant who was not executed because of mental retardation. He started in the drug business at age nine. What were the Justices of the Supreme Court doing when they were nine? His functioning was superior to theirs.