Michelle, in general, extended-release versions of medications do tend to keep kids more even throughout the day. We've never used either Lithobid or Depakote ER, but we have trialed ER versions of other medications. Right now my son is trialing Seroquel XR (switched from regular Seroquel) to see if his morning fatigue improves. It's only been a few days so the jury is still out.
Unfortunately, the only way you'll know if it's better, worse or about the same for Abbey is if you try it. If things do improve, I personally think it's worth the higher cost. We recently had to switch from generic Zonegran to brand Zonegran because the generic just wasn't as effective. Our psychiatrist and neuro said this is very common with anticonvulsants. So we are paying more, but it is worth it for efficacy.
You might want to make one change at a time instead of switching both medications at the same time. That way you'll know for certain what the effect of each medication switch is.
