Antidepressants don't usually make people gain weight, and definitely not the ones that people will prescribe you as your first few antidepressants
. (Some people don't respond to some antidepressants
, and have to try several). Weight gain is on
the list of possible symptoms of pretty much every psychiatric medication out there, but then so is suicidal thoughts, and that doesn't happen to lots of people who take the drugs otherwise they wouldn't be called antidepressants.