Welbutrin is usually best paired with another anti-depressant as it tends to augment the effects and sometimes helps the main med work better. As far as Zoloft being a weight gainer, most anti-depressants or ADs have this possibility. I take 60mg Prozac, 20gm Propranolol BID (twice a day), Xanax .5mg TID (three times a day) and 100mg Topamax BID for MDD, OCD, and anxiety disorder. I used to be on Welbutrin XL 150mg a day but I noticed it was making me too jittery and my sleep was unrestfull while on it so we stopped it. While I don't know your exact diagnosis it sounds like you could benefit from another AD along with the bupropion although this is my personal opinion and SHOULD NOT be taken as a professional or medical opinion. Do you smoke by chance? Sometimes docs will prescribe the Welbutrin to help with that along with it's anti-depressant effects, sort of the kill two birds with one stone approach.