For all classes of antidepressants, people must take regular doses for at least 3 to 4 weeks, sometimes longer, before they are likely to experience a full effect. They should continue taking the medication for an amount of time speciied by their doctor, even if they are feeling better, to prevent a relapse of the depression. he decision to stop taking medication should be made by the person and her doctor together, and should be done only under the doc tor’s supervision. Some medications need to be gradually stopped to give the body time to adjust. Although they are not habit-forming.