TNF and major depressive disorder: Consistently, altered expression of multiple inflammatory cytokines and chemokines including IL‐1β, TNF‐α, IL‐6, IL‐8, IFNα, CXCL4, CXCL7, and CCL4, and other inflammatory factors, such as CRP and MCP‐1, in the cerebrospinal fluid and/or peripheral blood are observed in patients with stress‐related psychiatric disorders such as depression, whereby high stress environments may exacerbate their perturbed regulation [8, 9, 10, 11, 12, 13, 14].