TNF and major depressive disorder: MDD is characterized by broad cytokine dysregulation, including elevated levels of IL - 1β, IL - 2, IL - 4, IL - 6, IL - 8, IL - 10, IL - 12, IL - 13, IL - 15, and TNF-α, alongside decreased IL - 5, IL - 12 p70, and TNF-β (25).