I'm taking a psychology class at school and I need to write a paper on a public figure. Can somebody confirm for me that RDJ has Bipolar Disorder or is this just a rumor. Any info. to the degree of his diagnoses is appreciated.

Yes he does

Yes, he's got Bipolar.
I read quote by Mel Gibson, who is a close friend of Robert, who said something like:
"One second he can be up and smiling, the next he gets depressed by something that crosses his mind, but deep down he's a good man."

Also in an interview the journalist was seated with Robert and Susan, and there's a fly in the room. Robert then puts it on himself to free the insect out the window, and he gets so agitated that he runs around the room with cup in hand chasing the tiny fly.

I found the last example quite funny when I read it.
He truly is something unique.

Ok. WOW!!! Sorry to say, but that's a definite rumor. Where did you hear that?