Haha, this is what happened to me! After usually staying up till somewhere between 3-5:00am, I got a job and had to be UP(!) at 5! I tried dialing it back, but... not easy! I do manage these days to not put it past midnight or 1, but yeah, it's usually 11:30 or midnight. And it's not because I'm tired, it just feels like an obligation. (Now, the schedule's a little lighter, and I don't have to get up till 5:45). Just the other night I loudly declared, "I hate normal people hours!" Lol.

Had to check mood chart, as it's not particularly consistent on number of hours. Looks like 5-6 1/2 is a pretty populated range. But 4 is fine too. I hate mornings regardless of how much sleep I've gotten. Though I don't typically get less than those 5 - 6 1/2, nights of less are no problem. No one would know. To the question of how one does not go manic... for me, if we start talking 0-2 hours, then yes, I'll be off to the races. Especially if the lack of sleep is connected with a trip or something I want to do.

On the other hand, depression usually means hypersomnia for me.