TLR4 and major depressive disorder: Sleep disorders activate the NF-κB, AP-1, and STAT signaling pathways, increasing the production of IL-6 and TNF by monocytes stimulated by TLR4, which leads to sustained activation of inflammatory responses and contributes to the development of diseases such as depression, dementia, cardiovascular diseases, and certain cancers (Irwin, 2019, Piber et al., 2022, Manigault et al., 2021).