In our review, we noticed that IFN-γ decreased with the administration of the SSRIs escitalopram (one study, moderate depression) [191], sertraline (one study, patients with unipolar depression) [204], and fluoxetine (one study, depressed patients, week 4) [193], as well as ketamine (one study, patients with treatment-resistant depression) [195] (Table 1 and Figure 2). The gene discussed is IFNG; the disease is major depressive disorder.