6 - PEDIATRICS
Sleep and the unique
features of physical, cognitive, and social-emotional development
that take place in adolescence must be considered separately
and in relationship to sleep in children and in adults. Not
only do the biological changes associated with puberty profoundly
affect sleep and wakefulness, but many environmental and social
factors are also implicated. Several sleep disorders are particularly
prevalent (delayed sleep phase syndrome) or emergent (narcolepsy)
in adolescence. Finally, the public health consequences of inadequate
sleep (academic failure, drowsy driving) and the potential for
primary and secondary prevention in this age group are important.
In The Last 5 Years
- Studies of normal
sleep and sleep patterns in adolescents have identified important
issues regarding the basic developmental physiology of sleep
and circadian rhythms in adolescence. The role of pubertal/hormonal
influences on circadian sleep-wake cycles and melatonin secretion
has been recognized, and the effects include development of
a relative phase delay (later sleep onset and wake times) in
early puberty and the development of a physiologically based
decrease in daytime alertness levels in mid- to late- puberty.
The genotypic expression in adolescence of delayed circadian
phase preference has also been explored as an important factor
determining the timing of sleep/wake cycles.
- Studies of homeostatic
regulation of sleep and wakefulness have demonstrated that sleep
needs in adolescence do not decline significantly, and that
optimal sleep amounts remain about 9 hours into late adolescence.
However, epidemiological research on "normal" sleep
patterns and amounts suggests that adolescents only average
7 to 7 1/2 hours of sleep per night, resulting in the accumulation
of a considerable sleep debt over time. These data suggest that
chronic partial sleep deprivation is a serious problem in this
age group and that particular subgroups may be at relatively
- Environmental and
social factors also impact significantly upon delayed sleep
onset in adolescents. For example, many adolescents have highly
irregular sleep/wake patterns from weekday to weekend. Another
important factor potentially contributing to insufficient sleep
is the early start time of many middle and high schools in the
- Chronic sleep restriction
in adolescents leads to significant neurobehavioral consequences
related to decline in alertness levels. These include a negative
impact on mood, vigilance and reaction time, attention, memory,
behavioral control and motivation. These impairments may in
turn be associated with significant declines in school and work/occupational
performance, increased risk-taking behaviors (use of alcohol,
illicit drugs, nicotine, caffeine, stimulants), and injuries.
Adolescent males, for example, are one of the highest risk groups
for fall-asleep motor vehicle crashes.
- Ascertain the impact
of chronic partial sleep deprivation on health outcomes, including
susceptibility to infection, metabolic consequences, immune
function, and use of potentially harmful alertness-promoting
agents such as caffeine and stimulant medications. Delineate
the effects of chronic partial sleep deprivation and sleepiness
in adolescents on higher level cognitive or '"executive"
functions, such as verbal creativity, and working memory, on
motivation, and on affect regulation. The assessment of health
outcomes should also include occupational and sports injuries,
and motor vehicle crashes, and should determine scope of the
problem, high risk groups, and interactions with other high-risk
behaviors and substances (alcohol, marijuana, etc.).
- Define the specific
neurophysiologic mechanisms involved in the relationship between
sleep and circadian timing and puberty.
- Determine the extent,
patterns, and psychosocial factors responsible for chronic sleep
restriction in adolescence. These studies should include cross-cultural
analyses and should also include special and high-risk populations
such as adolescents with co-morbid psychiatric conditions, mood
disorders, attention deficit hyperactivity disorder (ADHD),
and chronic illness.
- Determine the impact
of interventions to address chronic sleep restriction in adolescents,
including later school start times and high school sleep education
- Determine the biopsychosocial
and genetic factors that result in delayed sleep phase syndrome
in adolescents, and assess the safety and efficacy of various
treatment modalities, including administration of exogenous
melatonin, chronotherapy, and bright light therapy.