I've been on lamictal (250 mg) for several years & experienced no weight gain until I went on seroquel & zyprexa at the same time (talk about ballooning up!). Most of the literature suggests that lamictal is fairly weight neutral. It's been an effective mood stabilizer for me. I think everyone's weight can fluctuate 5-10 pounds, but I gained 60 pounds in 6 months on the seroquel & zyprexa. I've only been off of them for a few months, so it's too early to tell how much of the weight gain was metabolic & how much was the increased appetite these meds caused.