“…many narcissists see the world as a chess game in which they must think ahead in order to maintain the advantage they feel they deserve. For this reason, impulsivity is not considered a classic trait of narcissism. Trump’s obvious rashness, then, allows for an unfortunate combination of traits. “The impulsivity and the lack of deliberate forethought about things,” warns Miller, “paired with the overconfidence, are the most troubling parts for me.”
The best article I’ve seen on Trump’s mental health…
http://www.rollingstone.com/politics/features/trump-and-the-pathology-of-narcissism-w474896