Are highly intelligent people more prone to mental illness? OR --?

[KHAAAAN!]

No, but highly intelligent people tend to think and process information differently, and are known for displaying eccentricities in their behavior. This doesn't make them mentally ill, though.

U.S. presidents are not highly intelligent people, despite what they would have you believe. Though yes, most of them (including our current president) are narcissists and may even be psychopathic.

Psychopaths are not nearly as logical as you think. Due to their inability to empathize and correctly relate with other members of their own species, their thought process is incredibly skewed, typically involving delusions of grandeur. Their decision-making process is not based on intelligence, but impulse. Most cannot plan ahead, hold down jobs, or maintain social relationships for very long. Most have extensive criminal records that indicate they are anything but highly intelligent.

A psychopath's success in the corporate or political world is due entirely to stepping on everybody around them, and having no qualms with lying, cheating, and stealing to get to the top. Do not mistake this for intellect, this is behavior most of us grow out of by the time we're 8. Their success is based on who they bribe, who gives them money, who fixes the media to pain them in a better or worse light, and what connections they have socially that they by some miracle have not burned yet. Narcissists and psychopaths do not rise high politically because of intellect, they rise up with a lot of @ss kissing and lying. Do -not- mistake these simpletons for intelligent. They are pseudo-intellectuals, just because they are good at public speaking and like to think they are super smart doesn't make it true.

Many of these people frequently remind us that they are incapable of functioning without a team of aides.