I found Zyprexa to be a miracle drug. It helped with everything. But, I gained 25 pounds while on it. I'm not sure, though, if it was the Zyprexa or thyroid issues. My doctor feels it's Zyprexa. Zyprexa and Seroquel are very similar in their chemical structure and both tend to cause weight gain (quoting doctor). Seroquel never did anything for me, though, that's why I went on to Zyprexa.
Since then, I've switched to Risperdal, which also does some great things, it really seems to help with agitation for me, although since I'm bipolar II, I don't get extreme manias. It has completely fixed my insomnia problem (I take it at night). My doctor says it's more weight-neutral than Zyprexa. Risperdal isn't as dramatic of a change for me, but it seems to be a great alternative to Zyprexa (and Seroquel), and is helping with a lot.