18 Apr 2019 Weight gain is a possible side effect of many antidepressant drugs. paroxetine (Paxil, Pexeva, Brisdelle); sertraline (Zoloft); fluoxetine (Prozac); citalopram (Celexa) Mirtazapine is less likely to make people gain weight compared with escitalopram (Lexapro, Cipralex), an SSRI;...