It's hard to know for me 100% whether going on the drugs caused weight gain (I believe and so do my parents that it did, since when my dose was raised to a high dose at around 10 years old I pretty quickly went from normal weight to overweight. However, I also loved eating as a kid haha). I know that I was able to lose weight when I put in the effort, very easily/normally even on high doses of both Zoloft and celexa. It did take effort in terms of eating healthy and smaller amounts and exercise