Many research studies reported that C-reactive protein (CRP) and high-sensitivity CRP (hs-CRP) markers of chronic inflammation have been associated with numerous clinical conditions, including cognitive decline and depression in old age [16–21]; the causative effects of higher CRP or hs-CRP inflammatory markers on cognitive impairment speculatively occurred via promoting vascular disease or as a result of the inflammatory process linked with disorders in many lifestyle factors including obesity, physical inability, and smoking [22]. The gene discussed is CRP; the disease is major depressive disorder.