To play devil's advocate a bit, perhaps the challenge isn't to rid ourselves of psychos, but to find a mechanism for ensuring a healthy mix of personalities in power. It takes different strokes to move the world.
Lets make it into a normal job. 40 hrs per week, an expectation of privacy for those in the role and their families, and remove the cameras from the debating chambers so they can actually speak their minds instead of grandstanding for the home audience. Reduce the length of elections to 2 months max so that campaigning isn't a full time job in itself too