I'm not bipolar, but I do have depression. I can have long spans of being "normal" and then land in a funk for a week or more, greatly affecting my production.

At those times, I tell my account manager that I'm struggling so she knows why my numbers aren't up to par or why I'm rejecting some of the more difficult reports that are in queue (I do medical transcription, and when I'm fighting a down phase, it's really hard to muddle through some of the ESL doctors' work).

Of course it probably helps that I'm in Wisconsin and the head office is in California. I don't have to disclose any of this face to face.