Children’s Sleep and Development: From Infancy Through Adolescence

Overview

Sleep during childhood and adolescence is not merely a scaled-down version of adult sleep — it is a qualitatively different and developmentally critical process that undergoes profound transformations from birth through the teenage years. The newborn spends approximately 16-17 hours per day in sleep, roughly half of it in active (REM-like) sleep that drives brain development. By adolescence, the teenager requires 8-10 hours but typically obtains far less, as a biologically driven circadian shift toward later timing collides with early school start times — a collision with measurable consequences for academic performance, mental health, and physical safety.

The neuroscience of pediatric sleep has advanced significantly in recent decades, yielding insights that challenge long-held assumptions and inform evidence-based guidance for parents, educators, and clinicians. The co-sleeping debate illustrates the complexity: anthropological and evolutionary perspectives (championed by James McKenna at Notre Dame) emphasize that mother-infant co-sleeping is the biological norm for our species and facilitates breastfeeding and physiological regulation, while the American Academy of Pediatrics (AAP) recommends room-sharing without bed-sharing based on sudden infant death syndrome (SIDS) risk data. Both perspectives hold validity within their frameworks, and the integrative clinician must navigate this tension with nuance.

Sleep problems in children are extraordinarily common — affecting 25-50% depending on age and definition — yet frequently go unrecognized by pediatricians and parents alike. The consequences of inadequate pediatric sleep extend far beyond daytime sleepiness: impaired learning and memory consolidation, behavioral problems that mimic or exacerbate ADHD, emotional dysregulation, metabolic dysfunction, growth impairment, and increased susceptibility to infection. Understanding the unique features of pediatric sleep across developmental stages is essential for supporting the healthy development of the whole child.

Infant Sleep Architecture

The Newborn Sleep Landscape

Newborn sleep is fundamentally different from adult sleep in architecture, timing, and regulation. The newborn sleeps approximately 16-17 hours per day in 2-4 hour bouts distributed across the 24-hour period, reflecting the immaturity of the circadian system (the SCN is functional but not yet entrained to the light-dark cycle) and the dominance of homeostatic sleep pressure driven by rapid metabolic demands.

Newborn sleep consists of two states: active sleep (the developmental precursor to REM sleep) and quiet sleep (the precursor to NREM sleep). Active sleep constitutes approximately 50% of total sleep in the full-term newborn (compared to 20-25% REM in adults), reflecting its critical role in brain development. During active sleep, the immature brain generates enormous amounts of spontaneous neural activity that drives synaptogenesis, neural circuit refinement, and myelination. Premature infants may spend up to 80% of sleep in active sleep, underscoring its developmental importance.

The transition from the polyphasic sleep pattern of newborns to the consolidated monophasic (or biphasic) pattern of adults follows a predictable developmental trajectory. By 3-4 months, the circadian system begins to entrain to the light-dark cycle, and most infants develop a longer nocturnal sleep period. By 6-9 months, most infants are capable of sleeping 6-8 consecutive hours at night, though individual variation is substantial. True sleep stage differentiation (into recognizable N1, N2, N3, and REM) emerges by approximately 6 months of age.

Sleep Milestones

Key developmental milestones in infant sleep include: the emergence of circadian melatonin secretion (approximately 2-3 months), the consolidation of nighttime sleep into a primary block (3-6 months), the reduction from 3-4 naps to 2 (6-9 months), the reduction to 1 nap (12-18 months), and the eventual elimination of napping (3-5 years, with significant cultural and individual variation). Each transition reflects maturation of circadian, homeostatic, and neurodevelopmental systems.

Sleep onset associations — the conditions present when the infant falls asleep (rocking, nursing, being held) — are the primary determinant of nighttime waking patterns. An infant who falls asleep at the breast and is then placed in the crib may wake when the sleep cycle transitions to a lighter stage and find the conditions different from those at sleep onset, triggering a cry for the restoration of those conditions. This is not a sleep disorder but a normal consequence of associative learning.

The Co-Sleeping Debate

The Evolutionary Perspective: James McKenna

James McKenna, director of the Mother-Baby Behavioral Sleep Laboratory at the University of Notre Dame, has spent decades documenting the physiology of mother-infant co-sleeping. His research demonstrates that when mother and breastfeeding infant share a sleep surface, they engage in an intricate nocturnal dance: synchronized arousals, mutual temperature regulation, breastfeeding facilitation (co-sleeping mothers breastfeed approximately three times more frequently at night), CO2 sharing (the mother’s exhaled CO2 may stimulate infant breathing), and reciprocal physiological regulation.

McKenna argues that the solitary infant sleep arrangement common in Western societies represents a radical departure from the biological norm of our species — an evolutionary mismatch with potential consequences. He distinguishes “breastsleeping” (breastfeeding mother sharing a safe sleep surface with her infant) from generic “bed-sharing,” arguing that the breastsleeping context carries different risk profiles due to the mother’s heightened responsiveness and the characteristic C-curl protective position assumed by breastfeeding mothers.

The AAP Position: Risk Reduction

The AAP recommends that infants sleep on their backs, on a firm, flat surface, in the parents’ room but not the parents’ bed, for at least the first 6 months (ideally 12 months). This recommendation is based on epidemiological data showing an association between bed-sharing and SIDS, particularly in the presence of modifiable risk factors: maternal smoking, alcohol or sedative use, sleeping on a sofa or soft surface, formula feeding, and prematurity.

However, the AAP acknowledges the complexity. The association between bed-sharing and SIDS is heavily confounded by these co-occurring risk factors, and when all modifiable risk factors are eliminated, the independent contribution of bed-sharing to SIDS risk is debated. The UK’s NICE guidelines and other international bodies take a more permissive stance, recognizing that exhausted parents who fall asleep unintentionally while feeding in a chair or on a sofa face far greater risks than those who plan a safe co-sleeping arrangement.

Navigating the Middle Ground

The integrative perspective honors both the evolutionary logic of co-sleeping and the real (if confounded) safety data. For families who choose co-sleeping, harm reduction is paramount: firm mattress (not a sofa, waterbed, or recliner), minimal blankets and pillows, no smoking by either parent, no alcohol or sedating medications, breastfeeding (which reduces SIDS risk and positions the baby safely), and placing the baby away from the bed edge. Sidecar bassinets that attach to the bed provide a compromise, allowing proximity without surface-sharing.

For families who choose separate sleeping, the arrangement should be in the parents’ room (room-sharing reduces SIDS risk by approximately 50%), on a firm mattress with no soft bedding, on the baby’s back, with a pacifier (associated with reduced SIDS risk).

Sleep Training Approaches

The Spectrum of Methods

Sleep training — the process of teaching an infant to fall asleep independently and self-soothe during nighttime awakenings — is among the most emotionally charged topics in parenting. The evidence supports its safety and efficacy, while the emotional intensity reflects genuine parental instinct and attachment concerns.

Graduated extinction (Ferber method): Parents put the child to bed drowsy but awake and respond to crying at progressively increasing intervals (3 minutes, then 5, then 10, etc.) with brief reassurance visits. The method typically produces significant improvement in sleep onset and nighttime waking within 3-7 days. Mindell et al. (2006), in a large meta-analysis, found strong evidence supporting graduated extinction.

Unmodified extinction (“cry it out”): Parents put the child to bed and do not respond to crying until the desired wake time. This method is the most rapid but the most emotionally difficult for parents. Gradisar et al. (2016) demonstrated that graduated extinction did not cause elevated cortisol, behavioral problems, or attachment insecurity at 12-month follow-up — addressing the primary concern of critics.

Gentle methods (chair method, pick up/put down, fading): These approaches minimize crying by maintaining parental presence while gradually reducing involvement. The chair method involves sitting in a chair next to the crib and progressively moving it farther away over days/weeks. Fading involves gradually reducing the amount of parental assistance at sleep onset. These methods are slower but more palatable for parents who cannot tolerate infant crying.

Bedtime fading: Temporarily delaying bedtime to increase sleep pressure, ensuring rapid sleep onset, and then gradually advancing bedtime to the desired time. This method is gentle and effective but requires patience and consistent scheduling.

The Safety Data

The most important message regarding sleep training is its demonstrated safety. The Gradisar et al. (2016) randomized controlled trial, published in Pediatrics, found no differences in cortisol levels, behavioral or emotional problems, or parent-child attachment at 12-month follow-up between graduated extinction, bedtime fading, and control groups. A 5-year follow-up study (Price et al., 2012) of a large sleep training trial found no adverse effects on child emotional, behavioral, or psychological functioning — and no adverse effects on parent-child relationship quality.

Conversely, chronic sleep disruption in both child and parents carries well-documented risks: maternal depression (which itself impairs attachment), parental relationship strain, accidental injury from exhausted parents, and impaired child development from fragmented sleep.

School Start Times and Adolescent Circadian Shift

The Biology of Adolescent Sleep Timing

Beginning around puberty and continuing through the late teens, a biological shift occurs in the circadian system: the timing of melatonin onset, the core body temperature rhythm, and the subjective alertness rhythm all delay by approximately 1-3 hours. This shift is driven by pubertal hormonal changes (gonadal steroids affect the SCN) and changes in the homeostatic sleep system (adenosine accumulation slows, meaning teenagers can sustain wakefulness longer before feeling sleepy).

The result is that the average adolescent cannot fall asleep before 11 PM and, requiring 8-10 hours of sleep, cannot wake alert before 7-8 AM. When school starts at 7:30 AM and the alarm rings at 6:30 AM, the teenager is chronically sleep-deprived by 1-2 hours per night — not due to poor choices (though screens and social media compound the problem) but due to biological timing that is fundamentally misaligned with the school schedule.

The Evidence for Later Start Times

The evidence supporting later school start times is robust and consistent. The American Academy of Pediatrics, the American Medical Association, and the CDC have all recommended that middle and high schools start no earlier than 8:30 AM. Studies of schools that have delayed start times consistently demonstrate: increased total sleep time (approximately 25-45 minutes per night), improved academic performance (grades and standardized test scores), reduced absenteeism, reduced car accidents among teen drivers (Danner and Phillips, 2008, documented a 16.5% decrease in teen car crashes following a 1-hour delay in start times), and improved mental health (reduced depression, anxiety, and suicidal ideation).

Despite this evidence, as of 2025, the average high school start time in the United States remains approximately 8:00 AM, with many schools starting at 7:15-7:30 AM. Barriers to change include bus scheduling logistics, after-school sports and activities, parental work schedules, and institutional inertia. California became the first state to mandate later start times (8:30 AM for high schools) in 2019, with implementation beginning in 2022.

Screen Time and Sleep

Mechanisms of Disruption

Screen use before bed disrupts pediatric sleep through multiple pathways: (1) blue light emission suppresses melatonin and delays the circadian clock; (2) content stimulation (social media, gaming, engaging videos) increases cognitive and emotional arousal, counteracting the wind-down process needed for sleep onset; (3) displacement — time spent on screens replaces time spent sleeping; and (4) notification-driven awakenings fragment sleep in children who keep devices in the bedroom.

A meta-analysis by Carter et al. (2016) found that bedtime screen use was consistently associated with reduced sleep duration, delayed sleep onset, and poor sleep quality in children and adolescents, with a dose-response relationship. The association was strongest for interactive media (social media, gaming) compared to passive viewing (television).

Evidence-Based Guidelines

The AAP recommends: no screen time for children under 18 months (except video chatting); limited, high-quality screen time (1 hour/day) for ages 2-5; and consistent limits for ages 6 and older, with particular attention to ensuring screens do not interfere with sleep, physical activity, or social interaction. For sleep specifically: all screens should be removed from the bedroom, screen use should cease at least 30-60 minutes before bed, and the blue light component should be minimized in the evening.

Sleep and ADHD

The Diagnostic Overlap

The relationship between sleep and ADHD is complex and bidirectional. Approximately 25-50% of children with ADHD have clinically significant sleep problems, including difficulty falling asleep, restless sleep, frequent awakenings, and daytime sleepiness. Conversely, sleep deprivation produces symptoms in children that closely mimic ADHD: inattention, hyperactivity (paradoxically, sleep-deprived children often become more active, not less), impulsivity, and emotional dysregulation.

This overlap creates a diagnostic challenge: some children diagnosed with ADHD may actually have primary sleep disorders (sleep apnea, restless legs, delayed sleep phase) whose symptoms mimic or exacerbate ADHD. Gruber et al. (2012) demonstrated that extending sleep by just 27 minutes per night in healthy school-age children significantly improved teacher-rated behavioral and emotional regulation, while restricting sleep by a similar amount produced deterioration equivalent to a clinically meaningful difference.

Sleep-disordered breathing (snoring, mouth breathing, sleep apnea due to adenotonsillar hypertrophy) is particularly important to screen for in children with ADHD-like symptoms. Adenotonsillectomy can dramatically improve behavioral symptoms in these children, sometimes eliminating the need for stimulant medication.

ADHD medications (methylphenidate, amphetamines) can themselves disrupt sleep, particularly when taken later in the day. Careful medication timing, melatonin supplementation (which has strong evidence in pediatric ADHD-related insomnia), and sleep hygiene optimization are essential components of ADHD management.

Clinical and Practical Applications

Pediatric sleep assessment should be routine at every well-child visit. The BEARS screening tool (Bedtime problems, Excessive daytime sleepiness, Awakenings during the night, Regularity and duration of sleep, Sleep-disordered breathing) provides a quick framework. Red flags requiring referral include: habitual snoring, witnessed apneas, severe behavioral problems with sleep disruption, suspected narcolepsy, or parasomnias with injury risk.

Age-appropriate sleep recommendations (AAP/National Sleep Foundation consensus): newborns 14-17 hours, infants 12-15 hours, toddlers 11-14 hours, preschoolers 10-13 hours, school-age children 9-11 hours, teenagers 8-10 hours. These include naps where appropriate.

Parent education is the primary intervention for most pediatric sleep problems. Consistent bedtime routines (bath, book, bed), age-appropriate bedtimes, and a screen-free bedroom solve the majority of behavioral sleep problems without formal sleep training. For persistent problems, behavioral interventions (graduated extinction or gentle methods, depending on parental preference and child temperament) are safe, effective, and should be offered before medication.

Four Directions Integration

• Serpent (Physical/Body): Children’s bodies are in a state of extraordinary growth and development, and sleep is the primary anabolic state during which growth hormone is secreted, neural circuits are refined, and immune memory is consolidated. The serpent’s wisdom reminds us that a child’s physical needs for sleep are not optional or negotiable — they are biological imperatives that override convenience, scheduling, and cultural pressure.

• Jaguar (Emotional/Heart): The emotional dimension of pediatric sleep is deeply embedded in attachment. The infant’s cry at bedtime is a call for connection; the parent’s response shapes the developing attachment system. Whether through co-sleeping or gentle sleep training, the emotional goal is the same: communicating to the child that they are safe, loved, and held — even in the dark, even when alone. The jaguar’s courage applies equally to the parent who must tolerate brief crying and to the parent who must resist cultural pressure to enforce independent sleep.

• Hummingbird (Soul/Mind): Sleep is the scaffold upon which children build their understanding of the world. Memory consolidation during sleep transforms the day’s experiences into lasting knowledge. The hummingbird’s journey of learning and exploration depends on adequate sleep for encoding, consolidation, and creative integration. When we sacrifice children’s sleep to academic pressure, we paradoxically undermine the very learning we seek to promote.

• Eagle (Spirit): From the eagle’s vantage, the modern crisis of pediatric sleep — screens in bedrooms, early school start times, overscheduled families — reflects a cultural disconnection from the natural rhythms that children’s developing brains and bodies require. The eagle’s transcendent perspective calls us to question a society that systematically deprives its children of sleep in pursuit of productivity, and to advocate for structural changes (later school start times, reduced screen exposure, protected rest periods) that honor the developmental process.

Cross-Disciplinary Connections

Pediatric sleep intersects with developmental neuroscience (sleep-dependent brain development, synaptic pruning, myelination), pediatrics (growth, immune development, SIDS prevention), education (school start times, learning optimization, ADHD management), psychology (attachment theory, behavioral modification, sleep training safety data), anthropology (cross-cultural sleeping arrangements, evolutionary perspectives), public health (screen time policies, school scheduling policy), otolaryngology (adenotonsillar hypertrophy and sleep-disordered breathing), and family medicine (parental sleep deprivation, postpartum depression, family systems).

Key Takeaways

• Infant sleep is qualitatively different from adult sleep, with ~50% active (REM-like) sleep serving critical brain development functions
• The co-sleeping debate requires nuanced navigation: evolutionary biology supports proximity, safety data supports risk factor management
• Sleep training (graduated extinction, gentle methods) is safe and effective, with no long-term adverse effects on attachment or emotional development
• The adolescent circadian shift is biological, not behavioral — school start times should accommodate this reality
• Screen use before bed disrupts pediatric sleep through light, stimulation, displacement, and notification-driven arousal
• Sleep deprivation symptoms in children closely mimic ADHD; sleep disorders should be screened before or alongside ADHD diagnosis
• Sleep-disordered breathing (snoring, apnea) in children may present as behavioral problems and responds to adenotonsillectomy
• Consistent bedtime routines and age-appropriate bedtimes solve most pediatric sleep problems without medication
• Adequate sleep is not a luxury for children — it is the primary substrate for healthy brain development

References and Further Reading

• McKenna, J. J., & Gettler, L. T. (2016). There is no such thing as infant sleep, there is no such thing as breastfeeding, there is only breastsleeping. Acta Paediatrica, 105(1), 17-21.
• Gradisar, M., et al. (2016). Behavioral interventions for infant sleep problems: A randomized controlled trial. Pediatrics, 137(6), e20151486.
• Mindell, J. A., et al. (2006). Behavioral treatment of bedtime problems and night wakings in infants and young children. Sleep, 29(10), 1263-1276.
• Owens, J., & Adolescent Sleep Working Group. (2014). Insufficient sleep in adolescents and young adults: An update on causes and consequences. Pediatrics, 134(3), e921-e932.
• Gruber, R., et al. (2012). Short sleep duration is associated with teacher-reported inattention and cognitive problems in healthy school-age children. Nature and Science of Sleep, 4, 33-40.
• Carter, B., et al. (2016). Association between portable screen-based media device access or use and sleep outcomes: A systematic review and meta-analysis. JAMA Pediatrics, 170(12), 1202-1208.
• Danner, F., & Phillips, B. (2008). Adolescent sleep, school start times, and teen motor vehicle crashes. Journal of Clinical Sleep Medicine, 4(6), 533-535.
• Price, A. M., et al. (2012). Five-year follow-up of harms and benefits of behavioral infant sleep intervention: Randomized trial. Pediatrics, 130(4), 643-651.