I tell everybody that I'm bipolar now that I'm on a mission here in Colorado to force our state judicial system to comply with the Americans with Disabilities Act and the U.S. Constitution Amendment 14 requiring our courts to be fully accessible to those with mental illnesses. But this doesn't answer your question.

Before my activist stance, I would only tell others of my bipolar disorder when I felt they had a need to know. Obviously, you're not going to go out with a potential partner and announce on the first couple of dates that you're bipolar. You might chase them away by their own fears of the dreaded BP. But don't keep it a secret either. Use your intuition to be your guide in informing others of your condition. If, at that point, they choose to disassociate with you, then they are not good friend or companion material anyway.

You ask what do you say to introduce the subject. Just whatever feels most comfortable to you. For example, I wouldn't advise anyone to list off each and every visit to the psyche ward, or how you took off to New York City to get a part on a Broadway musical. Stick to the basics.