Narcisstic Personality Disorder, where the patient believes they are the center of te world and no one else matters, is diagnosed both to find psychopaths (I discovered the disease after reading an article on a guy who killed both his parents then used his Dad's credit card to buy himself a £30,000 holiday for him and his girlfriend) and business managers! And Tom Tew.

OK, so that wasn't very interesting - I'm not good with random facts.