Sorry, but there's no specific, general answer --- it depends on many factors. What antidepressant you are taking, at what dose, how long you have been taking it for, and whether your depression is chemically over, for instance. The safest answer is indeed to go back to see the doctor who has been prescribing it all along, for re-assessment. If one stops too soon, there's a significant risk of the return of the depression, and if one stops too suddenly, some symptoms may arise, so one generally wants to stop gradually. Let your doctor re-assess the situation, and then, if he/she thinks this is indeed a good idea to stop, he/she will recommend a plan for stopping more comfortably.