I had a biploar teacher at high school, and she even got really sick and had a meltdown in class one day and didnt come back for a term.

No one minded. She's still teaching there now. She was great. I work in mental health with bipolar,and I've met loads of teachers who I have worked with when they are unwell. There are people everywhere working who have mental illness! They just don't tell.

If your worried you could tell your boss your early warning signs, if you are concerned you'll act weirdly in front of parents.. That way they could give you a heads up, and if a parent did find out who gave a damn they could be reassured the situation is being well managed by you and your boss.

Personally I think a bipolar teacher would be great - Energy, inspiration, enthusiasm, creativity - just what kids need