I think it comes down to both of the people's personalities. Patience, understanding of illness, and genuine companionship are very necessary.

I was diagnosed about a year ago, and my current girlfriend, who I had just met, was incredibly supportive. She stuck by my side through an extreme psychotic episode, including 3 months of jail time and 6 months of house arrest. I think I learned more from her about love than anybody else I've ever met, and I couldn't be more thankful.

Very ironically, she was diagnosed last month. We are both at the age that it seems to surface, and we both certainly have our individual issues. It may even be the reason our personalities work so well in the first place. She's BP2 and I'm BP1. The last 4 months or so, I've been "stable" and she has been all over the place. As short of a tolerance for irrationality and rudeness that I have, I have learned to be extremely patient with her, as she was with me (just in different ways).

The way I see it, it comes down to how hard the individuals are both willing to work. I don't think having the illness is a sole reason to avoid a serious relationship. I do think, however, many people with the illness left untreated are nowhere near stable enough on their own to try and manage the feelings of another person on a daily basis. This is just my opinion.