This report presents a rare case of adolescent patient treated by novel antidepressant vortioxetine for depressive disorder comorbid to narcolepsy type 1 (NT1) and newly diagnosed REM behavior disorder (RBD) and describes the overall clinical improvement of the conditions. Additionally, we discuss effect of vortioxetine on sleep architecture by evaluating objective polysomnographic studies before and on the treatment. We propose a possible efficacy of this multimodal serotoninergic agent in treatment of RBD associated with NT1.