Lyrica (pregabalin) has caused significant
weight gain over 18 months or so, but in two very
rapid bursts - the first time I started on it and reached a stable dose, and the second time I started using it again, on 450 - 600 mg/day. Weight gain started even at lower doses, however I was substantially underweight prior to using lyrica, so it didn't bother me initially. Fortunately at least some of that is water retention and it disappears fairly quickly.