I'm not but I think I know what it can be.
I can feel that life is wonderfull and in a moment I hate it, without any reason for both. Sometimes it happens a few times during an hour. Up-down-up-down.
Mostly I feel depressed(don't want anything, too tired to talk even to write the letters, feel guilty - smth like this), but a few times a year I feel a little bit like maniac: I can get an idea(sometimes weird usually) and forget almost everything else. Or I feel like I should buy smth right now(usually I'm not a shopaholic), so I buy and can give it back in a few days.
This year I made stars on a ceilling(inculding breaking in a shop 5 minutes before closing as I needed a magnet. I bet I woudn't die if I bought it next day but I really though I had to do it immediately), bought 2 guitars(I had one by the time and I hardly can play), booked a vacation and canceled it in a few days. I can't explain it.
I used to think it's normal but now I'm looking at my 3 guitars and I dunno, it's a little bit weird so may be it's smth like bipolar, I think it's not a real one as I still can keep working or don't take any credits, and so on. It just takes some 'life power'. Anyway I don't want any doctors or medicines.