It depends on the context, I guess. In more formal situations, such as going to a new doctor or having my med list reviewed, it's "I have bipolar disorder". But if I'm talking to somebody casually (and the subject happens to come up), I'll say "I'm bipolar". It doesn't matter, I learned awhile back that the illness was part of me (though not ALL of me) and not just a red-headed bastard child who followed me into the house. LOL