It may take days or weeks.

They are not addictive. You might continue to need them, a maximum of two weeks of symptoms after stopping.

The answer to your question involves a number of variables. Another way your question could be asked is "how long am I going to suffer from withdrawal from the antidepressants I took?" This depends on the type of antidepressant you took and how long you took it. A very good guide to answering these questions is found in the book called "The Antidepressant
Solution" by Joseph Glenmullen MD. This is a clear description of the pros and cons of using antidepressants and a guide to safely withdrawing from them.

Antidepressants usually aren't addictive but you can become dependent on them. If you taper off of them you may feel withdrawal symptoms for weeks to months depending on how long you were taking them.

If SSRI should be tapered down.