FIRST OF 2 PARTS
A thorough evaluation can identify modifiable factors and guide treatment
Sleep problems are common among children and adolescents,1 with prevalence rates of 25% to 40%.2-4 Young children most commonly exhibit what is referred to as bedtime problems and night wakenings, whereas children in middle childhood (age 4 to 12) through adolescence (age 13 to 17) report insomnia. For many children, these problems persist.3 Insufficient sleep in children and adolescents worsens inattention, daytime fatigue, and cognitive and behavioral deficits.5 Assessment and treatment of sleep problems in children and adolescents is critical because poor sleep among youth increases the risk for depression, self-harm, and suicide,6,7 increases family stress, and decreases parental well-being.1
This 2-part article describes the assessment, diagnosis, and treatment of sleep problems among children and adolescents. In part 1, we focus on:
- sleep architecture (circadian rhythms, stages of sleep)
- sleep in healthy youth (age 6 to 17) and those with attention-deficit/hyperactivity disorder (ADHD), depressive disorders, and anxiety
- how to assess sleep, and the differential diagnosis of behavioral sleep problems in pediatric patients.
In Part 2, we will cover psychotherapeutic and psychopharmacologic interventions for youth with insomnia, and describe an effective approach to consultation with pediatric sleep medicine specialists.
How much sleep do children and adolescents need?
Throughout their development, children spend 40% to 50% of their time asleep. Sleep schedules are based on circadian rhythms, which are physical, mental, and behavioral changes that follow an approximately 24-hour cycle. Human circadian rhythm varies between 24 and 25 hours and is vital in determining our sleep patterns. Exposure to sunlight drives our circadian rhythm, sending signals to our bodies to “turn on” melatonin production at night (ie, 9 pm melatonin secretion starts) and “turn off” melatonin secretion in the morning (ie, 7:30 am) in adults. Exposure to sunlight also drives circadian rhythms for children, and melatonin secretion production occurs earlier in the evening for children. Families are encouraged to expose children to bright light in the morning by taking an early walk, eating breakfast in a sunny room, or having adolescents open up the window shades rather than keeping their eyes shielded from the sun.2 How sleepy or alert a child could be is determined by the duration and quality of a child’s previous sleep, and how long they have been awake (“sleep drive”).2 The 3 states of sleep architecture are wake; non-rapid eye movement sleep; and rapid eye movement sleep (“dreaming” sleep) (Box2).
Box
Sleep architecture: An overview
Sleep architecture consists of 3 states: wake; non-rapid eye movement (NREM) sleep; and rapid eye movement (REM) sleep (“dreaming” sleep).2 These stages have distinct polysomnographic features of electroencephalographic EEG patterns, eye movements, and muscle tone.2 NREM sleep can be further divided into 3 stages: stage 1 (N1), stage 2 (N2), and stage 3 (N3). Stage 1 is the lightest stage and lasts for 30 seconds to 5 minutes; it is easy to wake up from stage 1 sleep. During stage 2 sleep, the body moves into a deeper sleep stage that is considered “true” sleep. This sleep stage is characterized by bursts of rhythmic rapid EEG activity known as spindles, as well as high-amplitude slow-wave spikes called K complexes.2 Stage 2 sleep lasts for 10 to 45 minutes. Stage 3, better known as “deep sleep,” slow-wave sleep, or delta sleep, is the most restorative sleep.2 Respiration is low and parasympathetic activity is high.2 It is difficult to be awakened during deep sleep, and if aroused, the person likely will feel confused or groggy. Deep sleep is followed by a return to lighter stage of sleep before the first REM sleep period begins.
REM sleep is the active stage of sleep. Breathing and heart rate become irregular, and the body experiences muscle atonia, or temporary paralysis, of arms and legs. When in REM sleep, individuals have the highest brain metabolic rates, and periodic bursts of eye movements.2 Most individuals move through stages of NREM and REM sleep in predicable ways, meaning they experience NREM sleep, return to a lighter stage of sleep after deep sleep, then move into REM sleep before the cycle repeats. It takes approximately 90 minutes for most adults to complete the NREM sleep cycle, and then REM sleep occurs before returning to NREM sleep.
In children, especially in infants and babies, sleep cycles are closer to 50 to 60 minutes. Newborns spend approximately 50% of their sleep in REM sleep, whereas adults spend 20% to 25% of their sleep in REM sleep. Children will spend more time in REM sleep until the third and fourth years of life, at which point REM gradually decreases to 20% to 25% by adulthood.
Sleep needs also change predictably throughout the lifespan. The National Sleep Foundation guidelines for sleep duration provide clinicians and parents with a range of recommended sleep for each stage of development. Infants require 14 to 17 hours of sleep, whereas adolescents need 8 to 10 hours by age 14 to 17.8 The key for clinicians is to determine if the child is within the recommended range, and how they are functioning on the number of hours of sleep they report. This allows for variation in how much sleep an individual child might need while acknowledging that some children within a specific age group might need more or less sleep than other children of the same age.
Sleep in healthy youth: Middle childhood
School-age children (age 6 to 12) typically need 9 to 10 hours of sleep over a 24-hour period.2 This developmental period is especially important for children to develop healthy sleep habits; however, developmentally appropriate cognitive and social/emotional factors might interfere with the quality and quantity of sleep. Middle childhood is a time when children can understand the dangers of the outside world (ie, violence, health problems) and resulting anxiety can disrupt sleep. Parents usually are less involved in bedtime as children approach adolescence, which leads to later bedtimes. At this stage, many children begin to take on more serious roles in their academics and extracurricular activities, peer relationships become more important, and use of electronics (eg, television, video games, internet, and handheld devices) increases—all of which compete with sleep.9 Frequent sleep issues during middle childhood include:
- irregular sleep-wake schedules
- later bedtimes
- decreased nighttime sleep
- increased caffeine intake
- reduced parental presence at bedtime
- daytime sleepiness.3
In school-age children, regular napping, falling asleep during short car rides, and daytime fatigue at school or home are cause for concern. When these symptoms are present, an evaluation is warranted.
Sleep in healthy youth: Adolescence
The National Sleep Foundation recommends adolescents obtain 8 to 10 hours of sleep per night; for some adolescents, as much as 11 hours of sleep per night might be appropriate.8 However, this contrasts with findings from the National Sleep Foundation’s Sleep in America Poll, which revealed that 75% of 12th graders report <8 hours of sleep nightly.10 Many adolescents experience delayed sleep phase syndrome or delayed sleep-wake phase disorder, which involves a persistent phase shift of >2 hours in the sleep-wake schedule that conflicts with the adolescent’s school, work, or lifestyle demands.11 Such circadian rhythm disorders typically result from a poor match between the sleep-wake schedule and the demands of the adolescent’s life, or a failure to synchronize their internal clock with a 24-hour circadian clock.12 Children typically become tired after sunset, but puberty is associated with reduced slow-wave sleep and changes in circadian rhythms. As a result, a 3-hour delay (delayed phase preference) is common among adolescents. At approximately age 20, people start to become tired after sunset and awaken earlier in the morning—a pattern driven by sunlight and the timing of melatonin release that will remain stable until the sixth decade of life.
Continue to: Effects of chronic sleep deprivation...