An important factor when recommending a medication during pregnancy is a patient’s own history of medication response. Since the past is generally predictive, restarting a medication that was previously effective is the most rapid and direct way to achieve remission. If the medication previously used is one with minimal data in pregnancy, it is worth considering a trial of a more-studied medication, for example an SSRI.On the other hand, a trial with a new SSRI in a patient who has previously failed to respond to another SSRI may only prolong the patient’s depres­sion. Ideally, any medication change should take place prior to pregnancy, since changing medications during pregnancy results in multiple exposures. Thus, for the younger woman (e.g., less than 35years old, who is hoping to become pregnant, and for whom there is time to try another medication), a trial of a more studied medica­tion such as an SSRI is a reasonable approach. However, unlike the younger patient, the woman over 35, perhaps with a history of infertility or multiple pregnancy losses, may not have reproductive time ahead to experiment with a new medication. In these cases, it is prudent to continue with a medication that has been effective, but may have somewhat less data to support its use in pregnancy.