I spent so much time in the nurse's office that I probably missed more than half the year at school. I was always getting "sick" with stomach aches, headaches, etc. I think this is how I showed depression. I also was extremely creative and I am pretty sure I suffered from delusions of grandeur. It was as if my play were real. I used to get very upset when kids would leave whatever game I was playing and go do something else. I took piano lessons and although I didn't like practicing, I knew that I would be discovered at a recital and would become a famous piano player.
I used to get so angry that I would stomp my feet as hard as I could hoping that I would either break through the floor or break my foot. I used to throw myself to the ground while running to try to get hurt so the other kids would pay attention to me. I used to picture tornadoes or dinosaurs tearing my neighborhood down whenever I got angry. I used to want to destroy things and I would often trash my room. I would immediately feel guilty and cry while I picked up all my toys and apologized to each one, kissing it before I put it away.
I think that pretty much fits the bipolar child description. I am sure there is more, but that is all I can remember at the moment.