Research on Child and Adolescent Mental Health

Science Case in Point: Sleep Regulation and Pubertal Maturation
Studies of sleep/wake regulation exemplify the opportunities afforded by combining knowledge about biologic maturation (puberty),
behavioral changes, and social influences such that the findings have implications for social policy. The fundamental issue is that many
adolescents obtain insuffcient amounts of sleep at a time in development (pubertal maturation) when the biological need for sleep
increases. Insufficient sleep can contribute to serious emotional and behavioral health consequences that include short-term as well as
possible long-term effects. Progress in understanding the causes of sleep deprivation (and ultimately strategies for early intervention)
has been informed significantly by research examining interactions between biologic systems, behavioral patterns, and social and
cultural influences within a developmental perspective. Scientific progress includes these main points, made below:
At a time in development (pubertal maturation) when the physiological need for sleep increases, many adolescents are obtaining less
sleep on school nights, largely as a result of late bedtimes combined with early school start times (Carskadon, 1999). The shift to later
bedtime in early adolescence is, at least in part, related to maturational changes near puberty that cause a shift in the circadian system
(biological clock) resulting in a biologically based tendency to stay up later and sleep in later (a shift from a more “lark” pattern to an
“owl” pattern during pubertal development)(Carskadon et al., 1993). These biological tendencies (activated by pubertal maturation)
interact strongly with behavioral/social factors in several important ways, including (1) less parental control over bedtime, (2) access to
highly arousing stimuli (TV, movies, video games) and social interactions (telephone and Internet) late at night, (3) peer influences
toward later bedtime, (4) access to stimulating substances (e.g., caffeine, nicotine), and (5) stress, anxiety, and worries that interfere
with falling asleep. In combination, these factors lead to sleep-onset times that occur at late hours (Carskadon et al., 1993). Thus, the
strong tendency for adolescents to adopt very late schedules (bedtime and wake time) results in a shift of the circadian system, which
adapts more quickly to phase delays than to phase advances (thus it is very difficult for adolescents to shift back to the early bedtimes
and rise times for school) (Carskadon, 1999). Despite an average bedtime between 11 p.m. and midnight, most high school students
must wake up between 6 and 6:30 a.m. on school days. It is not infrequent for high school students to obtain less than 6 hours of sleep
on school nights at a time in development when they typically require 8 to 9.5 hours of sleep per night (Carskadon, 1999). Individual
differences in anxiety, biologic clock, sleep needs, and social context can greatly amplify the affective and behavioral consequences of
insufficient sleep and erratic sleep/wake schedules (Dahl, 1999).
The short- and long-term consequences of insufficient sleep at this point in development are not fully understood. Preliminary data
clearly indicate a negative impact on school performance and learning, as well as decrements in mood and self-regulatory abilities.
More specifically, sleep deprivation is associated with irritability, poor concentration, and emotional lability, all of which create
additional stress in the lives of many adolescents. Sleep deprivation can also increase stimulant use during the day (e.g., caffeine or
nicotine), as well as extensive catch-up sleep on the weekends by sleeping in very late in the morning (which further interferes with the
slowly adapting circadian systems, resulting in jet-lag like symptoms when the adolescent tries to shift back to an early wake-up time
for school days). Sleep deprivation, mood disturbance, and impaired concentration and self-regulatory skills can spiral into more
severe symptoms of impairment in school and social functioning, which further erodes mood (Dahl, 1999).
Some policy-level decisions are already being enacted to address aspects of these problems; one such policy is adopting later start
times for high schools. Prelimary results from a controlled study of Minnesota school districts that have adopted later start times have
been encouraging, with improved grades and mood ratings in the first year after these changes were made (Wahlstrom et al., 1999).
Larger studies are currently in progress. Educational programs for adolescents are also being developed (similar to the nutrition
education programs enacted in the past 20 years). However, large-scale policy changes and early clinical interventions focused on
sleep and circadian aspects of adolescent health will require a great deal more interdisciplinary developmental research to better
understand these complex issues.
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