A review of neurophysiological relationships between sleep disorders and depression

This review critically synthesizes current neurophysiological findings on the comorbidity between depression and sleep disorders. Drawing upon a multidisciplinary body of literature, the paper delineates overlapping neurochemical, hormonal, and inflammatory mechanisms. Further, it explores the role of astrocytic dysfunction and glutamate-GABA imbalance in reinforcing pathological feedback loops. By adopting an integrative framework, this review underscores the bidirectional and systemic nature of sleep disorder-depression comorbidity, offering insights into shared pathophysiological substrates and potential therapeutic targets for future research. • The neurophysiological mechanisms of sleep-depression comorbidity are systematically reviewed. • A framework integrating monoamine, HPA axis, and inflammatory factor dysregulation is proposed. • Astrocytic dysfunction and GABA/glutamate imbalance are identified as key novel mechanisms. • Clarifying these shared targets provides direct pathways for novel therapeutic development. • Treating sleep disorders is posited as a viable strategy for improving depression outcomes.