In the course of the international development of tianeptine (T), depressed patients were recruited by 15 centres from Belgium, Italy, Portugal, Spain and Switzerland in a double-blind parallel group study versus placebo (P) and imipramine (I). Efficacy and safety of tianeptine are evaluated in the treatment of major depressions (single episode or recurrent) and depressed bipolar disorders. The initial severity of the depression is controlled by a MADRS score equal to or greater than 25. Rapid placebo responded are excluded during a placebo pre-inclusion period (duration: 1 week). After an increasing daily dose period (3 days), depressed patients are treated, until the 14th day (D14), at a constant daily dose (T: 37.5 mg; I: 150 mg; P: 3 capsules). After D14 and until the end of the 6th week, a flexible dosage can be used in accordance with the therapeutic efficacy and/or the potential adverse events (T: 25–50 mg; I: 100–200 mg; P: 2–4 capsules). The antidepressant efficacy is regularly evaluated by rating scales (MADRS, HSCL). Anxiety linked to depression is evaluated by the Hamilton Anxiety Rating Scale. The safety is controlled by clinical examination, laboratory parameters and a check-list of side-effects. Preliminary results are presented and discussed showing the interest of surveillance of trials in progress.