Methods/Design: The investigators propose to evaluate the first French psychoeducational program for depression named "ENVIE" in a multicenter randomized controlled trial. Its aim is to educate patients on the latest knowledge on depression and effective treatments through didactic and interactive sessions. Patients will experiment the latest innovating psychological skills (from acceptance and commitment therapy) to cope with depressive symptoms and maintain motivation in behavioral activation. In total, 332 unipolar non-chronic (< 2 years) outpatients with moderate to severe depression, without psychotic features, will be randomly allocated to the add-on ENVIE program (N=166) or to a waiting list (N=166). The follow-up will last 15 months and include 5 assessment visits (enrollment, 3, 6, 9, 12, 15 months).