In addition, mTOR signaling is involved in the antidepressant effects of some clinical antidepressants used as the first choice for treating patients with depression, including ketamine, escitalopram, paroxetine, and tranylcypromine (Table 4) (Zanos and Gould, 2018; Pham and Gardier, 2019). This evidence concerns the gene MTOR and major depressive disorder.