I developed hypothyroidism about 11 years ago and took Lithium for a good 6 years while taking Synthroid. My thyroid will never recover, but it's just one little pill to take. I think some doctors believe that if Lithium is very helpful without too many side effects that it can be worth it to continue even with thyroid issues, if they can be managed. That would be something to discuss with your prescriber.

I'm a fan of Tegretol XR, but I doubt a person would take that with Trileptal. I've read Tegretol can be more efficacious than Trileptal for some people. Tegretol does have more medication reactions than Trileptal and usually does require blood tests, though I've had many fewer than I did Lithium, and I don't believe there is as much of a risk of toxicity as Lithium.

Many people take antipsychotics as moodstabilizers. That's always an option. Not all moodstabilizers are weight gainers.