Lithium was my worst weight gain drug, probably just because it was first. Most people don't gain so much on it but I gained 60 lbs in the first 6 months. After that I don't think it ever caused more weight gain (depakote and Seroquel took care of that) but lithium made me go from XS scrubs to medium ones in a matter of weeks which was horrifying (medium not being big, just a big change from what I had been wearing and expensive to change all at once). I know people wondered but nobody asked me, they probably just talked behind my back which was fine with me.