I'm upfront about my bipolar with a lot of people and all my friends know. However, I'm also openly autistic so people already know I'm not "normal" and I am unable to attend school or go to work and am on disability. So there's less for me to lose by someone being unempathetic. I agree with trying to just apologize without trying to make it sound like you are blaming your bipolar, though having people alert you when they think there is a problem that you might recognize doesn't sound like a bad idea.