When I started on lithium, I initially gained about 5 pounds. Two months after that I lost 30 pounds in an extremely unhealthy way. I realized I couldn't live like that, and last summer my weight returned to my original set point. Lithium seems to be weight neutral for me. I didn't permanently gain any weight at all, the initial 5 pounds evened out. No loss of libido, no sedation. But it didn't help my mood either, and I'm currently being tapered off of it because it may have damaged my kidneys, but for some people, it really works.

I'm having good luck right now combining Seroquel and Abilify. I'm not sure if the seroquel caused weight gain - initially I was on Seroquel and Risperidone and the Risperidone definitely caused weight gain, but I lost it all when I went off of it. I've only been on the Abilify for 2 weeks or so, so I'm not sure about weight gain with that one. My psychiatrist picked it because she said it was good for depression and relatively weight-neutral.

Don't give up, you'll find the right combination eventually. Like psychehedone said, it's trial and error. When you hit that right combination, it's all worth it.