Have you tried a SAD lamp? I have one that is adjustable in intensity so that I control how much light I get which lets me prevent mania. I don't use it if I am manic or mixed so some years it doesn't get used at all but when I am depressed this time of year it really can help. Like I said, it's adjustable so I usually use it at 5-10% (I think they recommend 50%) and for 8-15 minutes (they recommend 15 minutes). It really does help.