Newer antidepressants don’t have the same side effect. While Paxil and
Zoloft do cause some weight gain, other SSRIs, like
Prozac, Celexa and Lexapro, don’t. For Paxil and Zoloft, the weight gain can add up to five to 40 pounds a year. Some people do experience weight gain with Lexapro or Celexa, but most don’t. In this case, it is not a surprise to have idiosyncratic responses, since the chemical structure of all the SSRIs is so similar.