The Healthspan Map · Sleep (Ch6)

Sleep hygiene - Clock & light

What this is linked to

Where Sleep hygiene - Clock & light is linked — 8 sources.In the order the Map holds them: strongest evidence first. That is a statement about the evidence, not about what matters most.
Nutrient or lever	Direction	Strength	Evidence type	What was found	Source
Sleep hygiene - Clock & light	Do this	Emerging	RCT / meta-analysis	Poor/short sleep and anxiety are bidirectionally linked; better sleep lowers physiological arousal.	De Nys et al. 2022 (opens in a new tab)
Sleep hygiene - Clock & light	Do this	Emerging	Systematic review	Sleep deprivation impairs attention and working memory; 7-8 h is optimal for cognition.	Sleep-cognition overview 2023 (opens in a new tab)
Sleep hygiene - Clock & light	Do this	Emerging	Cohort / observational	Consistent light/dark timing anchors the circadian clock and next-day alertness.	Morning light & sleep/alertness field study (PubMed 36058557) (opens in a new tab)
Sleep hygiene - Clock & light	Do this	Emerging	RCT / meta-analysis	Insomnia roughly doubles the risk of developing depression (OR 2.60); a core modifiable risk factor.	Baglioni et al. 2011 (opens in a new tab)
Sleep hygiene - Clock & light	Do this	Emerging	RCT / meta-analysis	Irregular sleep is a major migraine trigger; consistent sleep-wake schedules are a cornerstone of prevention.	Robblee & Starling 2019, Cleveland Clinic J Med; lifestyle-migraine meta 2024 (opens in a new tab)
Sleep hygiene - Clock & light	Do this	Emerging	Review / narrative	Irregular sleep is a major migraine trigger; consistent sleep-wake schedules are a cornerstone of prevention.	Robblee & Starling, "SEEDS for success: Lifestyle management in migraine", Cleve Clin J Med 2019 (opens in a new tab)
Sleep hygiene - Clock & light	Do this	Strong	RCT / trial	Light is the dominant melatonin synchronizer; blue/bright evening light suppresses melatonin, dim light and a dark room preserve it.	Evening light-melatonin studies (opens in a new tab)
Sleep hygiene - Clock & light	Do this	Emerging	RCT / meta-analysis	Poor sleep and elevated stress are bidirectionally linked; better sleep associates with lower cortisol.	De Nys et al. 2022 (physical activity, cortisol & sleep) (opens in a new tab)