随着社会节奏加快及作息模式改变，抑郁与失眠共病患病率呈显著上升趋势。临床数据显示，共病 患者存在药物不良反应显著、缓解率低及复发率高等局限性。近年研究揭示，昼夜节律系统可能通过“生物 钟基因-神经环路-行为表型”多级调控网络同时影响睡眠结构与情绪调节。本文从昼夜节律介导下的睡眠 结构出发，探讨抑郁失眠共病机制，通过对生物钟基因层面、神经通路机制、抑郁失眠临床表型等多层面的 深入探究，揭示其与睡眠-觉醒、情绪调节之间的双向关联，为理解抑郁失眠共病的内在机制提供关键线索， 也为开发新型双靶点药物及个体化疗法提供理论框架，为突破当前临床治疗瓶颈探寻新方向。

With the acceleration of social pace and changes in daily routines, the prevalence of comorbid depression and insomnia has shown a significant upward trend. Clinical data indicate that comorbid patients face limitations such as notable drug adverse reactions, low remission rates, and high recurrence rates. Recent studies have revealed that the circadian rhythm system may simultaneously influence sleep architecture and emotional regulation through a multilevel regulatory network of "circadian clock genes-neural circuits-behavioral phenotypes". Starting from the sleep architecture mediated by circadian rhythms, this article explores the mechanisms underlying the comorbidity of depression and insomnia. Through in-depth investigations at multiple levels, including circadian clock genes, neural pathway mechanisms, and clinical phenotypes of depression and insomnia, it uncovers the bidirectional associations between these factors and sleep-wake cycles and emotional regulation. This provides crucial clues for understanding the intrinsic mechanisms of the comorbidity of depression and insomnia, as well as a theoretical framework for developing novel dual-target drugs and individualized therapies, and explores new directions for overcoming current clinical treatment bottlenecks.