Opportunities1) Sleep plays a fundamental role in humanphysiology. Knowledge about sleep can poten-tially improve pain management, chronic dis-ease treatment, and cognitive outcomes inneurodegenerative disorders, along with co-ordinating drug bioavailability. For these in-dications and others, a new technology modelcan be envisioned for the bedroom as a treat-ment site within the home that becomes op-erational as we fall asleep. Applied sleepneuroscience should explore how sleep-wakerhythms can empower individuals to betterrespond to clinical interventions, as well ashelp individuals recover from each day’s pres-sures, thereby preparing them for tomorrow’sdisease risk.2) Sleep is associated with many aspects ofmental and physical well-being. Althoughsleep is acknowledged as a major contribu-tor to mental and physical health outcomes,this growing understanding has yet to becodified into NIH and other federal guidelinesthat would encourage clinical trial designersto incorporate sleep as a common variable ofinterest and to formalize the scheduling, col-lection, and reporting of biosample collectionwith respect to time of day and an individual’ssleep phase. With such mandates in placealong with open science practices, biomedicalresearch could synthesize information frommultiple levels of analysis to provide insightsinto the fundamental contributions of sleepto individual organ systems and emergentphysiology, as well as how sleep modifies thecourse of disease and response to experimen-tal treatments.3) Sleep health itself is multidimensional.Many investigations concerning human sleepare limited by an overly narrow focus on sleepdeprivation and primary sleep disorders, thuscreating a false dichotomy between typicaland atypical sleep. The very concept of sleephealth, which moves beyond clinical disor-ders to emphasize the positive contributionsof sleep to mental and physical well-being,suggests that all sleep gradations are rele-vant to health outcomes. To the extent that thisis the case, each aspect of sleep can become a“lever arm” in neuroscience to perpetuate goodhealth or improve disease-related outcomes.4) Sleep health may represent a pathway forreducing health disparities. Structural bar-riers, working independently or collectively, areknown to have adverse effects on sleep, withlikely effects on mental and physical health out-comes that enhance racial and ethnic dis-parities in health care. Reductions in healthdisparities may be aided with community-level engagement, investments in social ser-vices, and data-driven policies that (i) increaseawareness of the importance of sleep, (ii) creategreater vigilance for primary sleep disorders,and (iii) encourage discussion of sleep prob-lems with medical professionals. Public cam-paigns such as these offer the opportunity forsleep neuroscience to make a tangible differ-ence in the day-to-day lives of people in greatestneed of help.5) Sleep is becoming easier and less expen-sive to assess in the real world. The evolutionof sleep measurement outside the confines ofthe laboratory presents many opportunities toharness an individual’s own data in the serviceof personalized medical approaches that canimprove the ease with which a person’s sleepis conceptualized in relation to their health.Artificial intelligence and other big-data ana-lytics can also examine sleep at the cohort orpopulation scale, thus improving the availa-bility and utility of data gathered across multi-ple naturalistic contexts (104).

Clarify the neuroscientific mechanismsthat underlie different facets of sleep health.Although many studies have linked differentaspects of sleep to outcomes, there is relativelylittle work that delineates the specific path-ways by which this occurs. Perhaps answerslie in genetic studies. For example, peoplewith an autosomal dominant mutation in theb1-adrenergic receptor gene (ADRB1-A187V)(106), a missense mutation in the DEC2 gene(BHLHE41) (107), or a point mutation in neuro-peptide S receptor 1 gene (NPSR1) (108) seemto require less sleep than those in the generalpopulation. Further characterization of thesegenes may help uncover presently unknownmechanistic pathways for sleep duration andincrease the impetus to identify genes thatinfluence other dimensions of sleep health,such as sleep efficiency and satisfaction. Im-proved understanding of the overarching “ge-netics of sleep health” would enable clinicalinvestigators to develop genetic (along withsocial-environmental) profiles for the sleephealth of trial participants and patients, aswell as to consider when stronger or weakerassociations might be expected between sleepand health outcomes of interest.

Societal-level factorsSocietal-level factors are built from social-levelfactors. Societal factors include technology,public policy (91), geography (92), racism anddiscrimination (93), globalization and “24/7”society (i.e., general lifestyles of work and lei-sure in which people may be active at any hourand do not necessarily sleep consistently atnight). Although these factors are not readilymanipulable, recognizing their influence onsleep health can inform our understanding ofhow sleep is shaped and how this influencehas the potential to shape other health- anddisease-related outcomes.

Mental healthInsomnia is a well-established risk factor fordepression and is implicated across severalneuropsychiatric conditions, including anxiety,psychotic, and attention-deficit/hyperactivitydisorders (39). Elevated suicide risk is associ-ated with increased insomnia, nightmares, andhabitual sleep duration outside of the norma-tive range (40). Nocturnal wakefulness—simplybeing awake in the middle of the night—mayalso represent a risk factor for suicide (41, 42).In general, sleep disruption produces basicfunctional impairments in emotion regula-tion, recognition, reasoning, and memory(43). This may be driven by neurophysiologicchanges to cortical and subcortical structuresthat are unduly affected by acute or chronicsleep loss

Many studies have describedthe neurophysiology that contributes to sleepregulation, including the neuroanatomy of sleepand arousal-promoting circuitry (1); the dif-fuse, interconnected neurotransmitter systemsthat transition between non–rapid eye move-ment sleep (NREM), REM sleep, and wakefulness(2); and the core molecular clock mechanismand circadian pacemaker activity within thebrain (3). Additional work has delineated howsleep serves as a prerequisite for optimizingthe performance of critical biological func-tions, including those related to memory (4),waste clearance from the brain (5), and nu-trient metabolism (6).