Sleep disorders are a global public health problem. The Lancet 2023 data shows approximately 10-20% of global adults suffer from chronic insomnia; China’s rate is higher due to work stress, excessive electronic device use, and irregular schedules. Insufficient sleep is significantly associated with improve risks of cardiovascular disease, type 2 diabetes, depression, cognitive decline, and immune dysfunction.
## Biological Foundations of Sleep
**Circadian rhythm**: the body’s built-in 24-hour biological clock, regulated by the suprachiasmatic nucleus (SCN) and influenced by light (blue light suppresses melatonin secretion) and temperature. Melatonin is the chemical messenger of the circadian rhythm, secreted by the pineal gland in darkness to signal “time to sleep” — but it’s not a sleeping pill itself; it’s a timing calibrator.
**Sleep pressure (Process S)**: the longer one stays awake, the more adenosine accumulates in the brain, generating sleepiness. Caffeine works by blocking adenosine receptors to reduce sleepiness signals — but cannot reduce adenosine accumulation itself; caffeine metabolism leads to “adenosine rebound” (sleep debt).
**REM sleep**: the critical stage for memory consolidation and emotional processing, comprising 20-25% of normal sleep. Alcohol and benzodiazepine sleep aids significantly suppress REM sleep, damaging sleep quality while helping with initial sleep onset.
## Evidence-Based Intervention Ranking
**First-line recommendation — CBT-I**: both the American Academy of Sleep Medicine (AASM) and the European Sleep Research Society (ESRS) list CBT-I as the first-choice treatment for chronic insomnia. Core techniques: sleep restriction therapy (temporarily reducing time in bed to intensify sleep pressure), stimulus control (rebuilding the “bed = sleep” conditioned response), and cognitive restructuring (eliminating catastrophizing about insomnia). CBT-I can be delivered through digital platforms (Sleepio, sleep diary apps), with lasting effects and no side effects.
**Melatonin**: effective for sleep phase delay disorder (jet lag, shift workers); direct hypnotic effects for ordinary insomnia are limited; recommended dose is 0.5-1mg (far below the 3-10mg in most commercial products); long-term safety is good.
**TCM interventions**: Suanzaoren Decoction (Sour Jujube Seed Decoction) has shown improved sleep quality in multiple RCTs; primary active compounds jujubosides have sedative and 5-HT modulating effects — one of the relatively better-evidenced TCM sleep interventions.
See [Gut Microbiome and Health](https://sunqi.org/gut-microbiome-health-en/) and [AASM insomnia clinical practice guidelines](https://aasm.org/).
