I'm on Depakote (which is semi-sodium valproate). I was put on it for agitation and I take it alongside olanzapine and venlafaxine. I didn't think it was helping at all and it was added at the same time as the olanzapine/increase in venlafaxine, so I couldn't be sure which medication was doing what, but I really noticed a difference when I tried to reduce the dosage.
I've heard that the side effects can be pretty difficult to manage, but I haven't had any that I can definitely put down to the Depakote. I was told by my psychiatrist that it's important not to conceive whilst you're on it as it can cause abnormalities in the baby.
I hope it helps you.