Since the discovery of psychopharmacological treatments in the early 1950s, followed by the development of second-generation antidepressants, biological psychiatry has not achieved much progress. Recent technological advances in the field of non-invasive brain stimulation open new perspectives in the treatment of depressive disorders (MDD). Amongst them, transcranial direct current stimulation (tDCS) modulates cortical excitability and induces long-lasting effects. Here, we aimed at evaluating whether tDCS has potential to be developed as an innovative treatment in psychiatry. We conducted several studies in humans and animal models, exploring clinical and cognitive effects, especially in MDD. Our findings indicated beneficial clinical effects of tDCS. The data published to date are promising and supports the use of tDCS as a treatment for MDD. However, its place regarding other treatments still has to be determined before becoming a routine clinical treatment.