I agree with JonLaw about being able to spot people who need to be monitored and/or helped.

I knew a guy who ended up killing himself and his child while the police were outside his house with his wife. This guy was wound up way, way, way more tightly than anyone else I've ever met. I don't mean that he was just a really intense person. I mean that many things in his life went to extremes: he was way too intense about work, about politics, about women--- lots of stuff. I don't think he was a psychopath. Not at all. But I do think he was mentally ill and not treated (or not treated properly).