Interestingly, one study in Wistar-Kyoto rats, a putative animal model of depression, found that chronic administration of ketamine for 11 days at very low doses (0.25 or 0.5 mg/kg) did elevate phosphorylated mTOR in the hippocampus, yet did not affect autophagy markers (Akinfiresoye and Tizabi, 2013). Here, MTOR is linked to major depressive disorder.