FTO and major depressive disorder: Tricyclic antidepressants increase FTO expression and activate its epigenetic function in the VTA; eliminating m6A modification in the VTA is postulated to cause an antidepressant effect.372 Moreover, activation of FTO in the hippocampus relieves depression-like behaviors and reduces the density of dendritic spines and the number of branches in mice induced by chronic restraint stress, improving the synaptic plasticity.373 In contrast, only a few studies reported the association between the writer and the eraser protein and effects of antidepressants.