Hi I can't say about zoloft as I could not take it it made me rather sick. But I will let you know that I take a low dose of lamictal for my mood swings and anxiety and it helps. Does not get ridof it 100% but sure reduces it. MY issue is more about a slow metabolism causing weight gain. However I know the lamictal has not contributed to any weight gain.
Good luck. Hope this might be of help to you.