[Exploring mechanism of "treating different diseases with the same method" for depression and Alzheimer's disease based on "liver-spleen-kidney" axis and advances in traditional Chinese medicine intervention].

Depression(major depressive disorder, MDD) and Alzheimer's disease(AD) are two highly prevalent neuropsychiatric disorders. With the aging population, their comorbidity rate continues to rise. The pathogenesis of MDD and AD is complex, and modern medicine still lacks strategies that can simultaneously intervene in the core processes of both diseases. The theory of "treating different diseases with the same method" in traditional Chinese medicine(TCM) is an important therapeutic principle, which means that different diseases showing identical syndromes during their development can be treated with the same approach. This provides a TCM perspective for the diagnosis and treatment of their comorbidity. Based on the theory of the "liver-spleen-kidney" axis, this study identified that MDD and AD shared common pathogenesis: liver dysfunction in free coursing, spleen dysfunction in transportation, and kidney essence deficiency. It further connected this pathogenesis with the dysregulation of the neuroendocrine-immune(NEI) network in modern medicine, revealing common pathological mechanisms in neuroinflammation, dysfunction of the "hypothalamic-pituitary-adrenal"(HPA) axis, and gut microbiota dysbiosis. Meanwhile, it also reviewed specific mechanisms of TCM herbs such as Bupleuri Radix(Chaihu), Paeoniae Radix Alba(Baishao), and Astragali Radix(Huangqi), as well as their active components, in treating MDD and AD by regulating the NEI network through multiple targets and pathways. This may provide evidence for the application of the "treating different diseases with the same method" theory and broaden the perspective for the treatment of MDD and AD.