Lithium and lamictal are not like ADs in that they won't send you higher. They are supposed to be a good combination; lithium helps highs and lamictal helps balance out lows. I've stopped both cold turkey (which I don't recommend; I had to do it medically as I was blessed with the lamictal rash (don't panic, it's really, really rare) and multiple lithium toxicities (also not that common if you are getting your levels checked routinely; I just seem to process it weirdly) and I had no problems with either.

Some people have memory loss with ECT. It is usually temporary and usually only the time before and during treatments but sometimes it is more than that and that's hard to live with. I think it's probably also really hard to handle having gone through it and not getting the results you want since it is a pretty intense experience. There are probably other reasons; those are the ones I've read about.