This is not only what my psychiatrist told me, but something I have also read. When I was being weaned off my Lithium by my psychiatrist, he did so slowly. I recall I was on 900 mg. He reduced my Lithium by 300 mg every two months, so it took four months, and that was done even though kidney damage was discovered. Even the nephrologist (kidney doctor) I had started to see, at pdoc's suggestion) thought that reduction plan was smart. Of course my psychiatrist did consult with the nephrologist before implementing the plan. The whole process went extremely well!