Have you tried an MAOI? Emsam is awesome for me and I failed everything else before I went on it. It is a patch so it isn't absorbed through the stomach which decreases the food restrictions that other MAOIs have. At the lowest dose you have no restrictions and honestly the restrictions aren't so bad once you are used to them (no cheese but mozarella and no Chinese food sucks but you get used to even those; for me I got used to it really quickly because it was so effective).

It can be agitating at first but that levels off and it's non-sedating, weight neutral/slight weight loss (for me I lost a good bit but gained it back when I had increased seroquel and then especially when I went on clozaril).

I really can't recommend it enough and as I said, I've been on nearly everything at some point.

My other thought was rTMS? I know my pdoc thinks it can be pretty effective and she's done research on it. It's not an option for me because Medicare doesn't cover it for bipolar and even if they did the co-pay would be too much for me to ever afford. But I did look into it when I was trying to avoid clozaril (which is also a really effective med when you are at the end of the line of meds).