Potential value of slow‐wave sleep in management of chronic insomnia disorder

Chronic insomnia disorder (CID), acknowledged as the most common sleep disorder, has traditionally been diagnosed and managed with a focus on reducing sleep onset latency and extending total sleep duration. However, the critical importance of slow‐wave sleep (SWS), a key indicator of objective sleep quality, has been largely overlooked in clinical practice. This review consolidates recent advances in the understanding of SWS. It begins by elucidating the physiological roles and regulatory mechanisms of SWS, with an emphasis on its neurorestorative and homeostatic functions. Building on this foundation, we then delineate SWS abnormalities and their associations with adverse clinical outcomes in CID. Finally, we discuss pharmacological and non‐pharmacological interventions that effectively enhance SWS. This review summarizes existing research on SWS in CID and outlines the clinical relevance of SWS for CID management, and offers tentative perspectives for evaluating therapeutic outcomes.