Try reducing Depakote to lose weight. Given that you are on the highest FDA-approved dose of Geodon and on Lithium, you should not need that much Depakote (Divalproex). Depakote is causing your weight gain, most likely.

Another option if he is so conservative is to lower Depakote to, say, 1000-1250 but raise Lithium by 300 mg.

So what do you take for depression?