Narcissism is a common catchphrase these days. It seems many of us hear it almost daily, and in all sorts of contexts, and applied to all sorts of people. But what is NPD, and how is it different from narcissistic personality traits (or for that matter, how's it different from just being a selfish jerk)? Narcissistic Personality Disorder NPD is a personality disorder that is diagnosed by a mental health professional based on a set of specific criteria outlined in the Diagnos