TNF and major depressive disorder: TNF-α concentrations are known to be increased after acute stress (Marsland et al., 2017), in depression (Dowlati et al., 2010) and anxiety disorders/PTSD (Renna et al., 2018; Yang and Jiang, 2020), and there is also evidence suggesting an involvement of TNF-α in noise-induced hearing loss and tinnitus (Wang et al., 2019; Shulman et al., 2021).