I agree with the others. I would tread lightly when disclosing you have a mental illness. It came out at my last job, I ended up in the hospital and the place is a gossip factory, so there was no avoiding it. Some people were very supportive, but others were skeptical, downright mean and resentful that I got time off while others just treated me differently or avoided me altogether. You shouldn't be ashamed of your illness, but having everyone around you know is different and I doubt it will stay under wraps very long. In my case, you don't "have" bipolar disorder, you are bipolar. It's the same with depression and other mental illnesses and they will use it to explain everything. I found I could no longer just have a good or bad day like anyone else. If I had one it meant I was about to go nuts.