IL6 and depressive symptom measurement: Large-scale cohort studies and meta-analysis provide the strong evidence that the high levels of IL-6 and CRP are closely related to the poor outcomes due to various causes, including cancer, cardiovascular disease and the metabolic syndrome.[60] High CRP level is associated with regional volume abnormalities,[61–63] Alzheimer disease,[64,65] and depression.[66,67] IL-6 exerts important functions in integrating behavioral phenotypes, neurobiology, and immunology.