 In the present research project, we plan on conducting an enriched maintenance study of the use of tianeptine as an adjunctive therapy in bipolar depression. All participants will receive tianeptine in an open label manner for a period of two months, following which they will be assigned randomly to the treatment with tianeptine or placebo in a double-blind fashion for six months. All patients will remain on treatment as usual for the duration of the trial. This trial will allow the investigation of the efficacy and tolerability of tianeptine 37.5mgday as an adjunctive treatment of bipolar depression and its impact on clinical variables associated with the aftermath of a bipolar depression episode. Considering that tianeptine is approved to be used orally in humans and has been on the market for depression, a low risk intervention using a novel approach may be provided by this clinical trial. Along with clinical response, we will prospectively evaluate the improvement in working and declarative memory, two cognitive prefrontal- and hippocampus-dependent processes, respectively, and the effects of tianeptine on serum BDNF levels. 