MY younger brother can be the KINDEST loving person and brother in the world (he is 15) or he can be the most selfish, mean and cruel person with his words and actions. He likes to think that he is "on top of the world" and that everyone else is lower than him and that it is an "Honor" for anyone to know him. He seems to have two different personalities....do you think these may be signs of bipolar disorder? I have ADHD/OCD and my dad has OCPD (even though he is in denial) but OCD/ADHD run in my dad's side of the family.....thanks for your input.