Uhm. Mixed I think. My therapeudic dose was 900mg. It kicked in after a few weeks and worked for quite awhile. I did have to change to something else eventually (nothing seems to work forever with me). I didn't mind lithium. It did make me thirsty ALL the time, and I had hand tremors that were pretty annoying, but it was working, so I could live with the side effects. It was NOT my last resort. I'm currently on tegretol. I think working within a week is too quick an estimate, particularly if you aren't on a therapeudic dose yet. Has she had blood levels drawn? Unless it is within therapeudic levels, it isn't going to do much.