I think 'manic-depressive' is a better description of it, at least my own experience of it. I use the term 'bipolar' because that's what people know, and if I hear it tossed around casually, I have no problem educating the offender(s) about the disorder. What's funny is their reaction; I don't "look" mentally ill (whatever that looks like) and I don't act "crazy", so when I talk about being/having bipolar it tends to make people go "Oh, wow, I didn't know that, I'm sorry!!" I like that.