TNF and major depressive disorder: For example, elevated levels of inflammatory biomarkers CRP, IL-1β and TNF-α have been linked to poor antidepressant treatment response in depressed patients (Cattaneo et al., 2013, Uher et al., 2014), indicating that inflammatory molecules may have role as predictive biomarkers in depression treatment, for example in estimating the efficacy or suitability of a treatment before the trial.