Toludesvenlafaxine significantly reversed depressive-like behaviors in all three paradigms used and increased the density of dendritic spines in the CA1 hippocampal neurons and reduced the hypermethylation of the oxytocin receptor gene (Oxtr) in the hippocampus of mice experiencing the “two hits” stress; therefore, it may reduce depression vulnerability via epigenetic mechanisms involving the Oxtr expression [80]. This evidence concerns the gene OXTR and major depressive disorder.