[Ketamine's fast-acting antidepressant mechanisms: state of the art and new research perspectives].

About a third of patients with major depressive disorder (MDD) do not have an adequate response to first-line antidepressant treatment, i.e., develop a treatment-resistant depression (TRD). The partial understanding of MDD pathophysiology currently constitutes the major barrier to clinical and research progress on this topic. However, recent advances in genome editing techniques as well as in induced pluripotent stem cells (iPSC) technology are offering unprecedented opportunities in both human disease modelling and drug discovery. These technology progresses have been enabling to set up disease-relevant patient-specific in vitro disease modeling for various mental disorders. The resulting models have the potential to significantly improve pathophysiologic understanding of MDD and then overcome some limitations inherent to animal and post-mortem models. More recently, psychiatry started to deal with the fast acting antidepressant ketamine and its derivates. Although ketamine appears to have the potential to transform the treatment of depression, its specific mechanisms of action are only partially known. Such knowledge is necessary to develop a model to understand the mechanisms behind fast-acting antidepressants, which may enable the discovery of novel glutamatergic compounds for the treatment of MDD. After discussing both the current understanding of ketamine's mechanisms of action, and the state of the art of human iPSC technology, the authors will introduce the implementation of a TRD model based on iPSC human technology and aimed at studying the ketamine's fast acting antidepressant mechanisms of action.