The First Experimental Study on Transference work - In Teenagers (FEST-IT) will be a randomized clinical trial, which will be designed to explore effects of transference work in dynamic psychotherapy in adolescents with major depressive disorder (MDD). The design of the study is a so-called dismantling design, in which a single component is added and/or varied to an existent treatment method (psychodynamic psychotherapy). Thus, the efficiency of a specific technique (transference interventions) can be identified.