How long can i be on ssri antidepressants if i have autism?

No definite answer : At this point in time there are no clear guidelines in any patient population defining the upper limit of years they can be used. Just as with any medication the continued use should be based on the risk/benefit profile. These meds have been around long enough that there are patients who have been using them for 20 plus years. You should always be able to say that there is iimproved functioning.

As Needed: As long as needed. If the side effects are monitered and you have no problems.