MTOR and major depressive disorder: The rapidity and relatively long-term efficacy of ketamine for depression (and potentially SUDs) have been linked, like ibogaine/noribogaine and classic psychedelics, to a rapid synthesis of brain- and/or glial-derived growth factors along with the activation of the mTOR signaling pathway, leading to synaptogenesis (Li et al., 2010; Autry et al., 2011; Ly et al., 2018; Aleksandrova and Phillips, 2021).