From every account I’ve heard (including my own) it depends on how high the dose and for how long you were taking them. In my experience going cold turkey was pretty similar to quitting nicotine, the first two weeks being the worst but everything after that being much easier. You can expect to get occasional zaps for a long ass time after that. I will occasionally feel something and go “wait was that an ssri zap?” even two and a half years off lexapro.