CRP and major depressive disorder: Such as, interleukin-6 (IL-6) is one of the most important inflammatory biomarker and plays a vital role in the development of IBD.[10] The increase of serum IL-6 level could result in changes in brain structure and lead to neuropsychiatric disorders.[11–13] In addition, high C-reactive protein (CRP) level is associated with regional volume abnormalities, Alzheimer disease, and depression.