IL10 and major depressive disorder: Serum inflammatory cytokine levels are elevated in patients with depression, and antidepressant drugs, such as SSRIs, can decrease the pro-inflammatory cytokines IL-6, IL-1β, TNF-α, and IFN-γ, or increase the anti-inflammatory cytokines, such as IL-10, IL-4, IL-13 (46, 47).