Methodological considerations

This review focuses on data collected in children and adolescents. There is a large and well-developed literature on sleep deprivation in adults that can provide initial guidance for pediatric research, but cannot be extrapolated to children without studying children, for several reasons. Whereas the large majority of adult experimental studies have examined the impact of 1 to 2 nights of complete sleep deprivation, it is reasonable to question how these findings generalize to children, whose overall sleep need is greater and who far more often experience chronic partial sleep restriction than total sleep deprivation. Moreover, circadian rhythms shift developmentally, and adolescence brings tremendous changes in sleep physiology, particularly within the lower slow-wave electroencephalographic (EEG) frequency ranges, that may alter the response to sleep restriction. Finally, the contexts in which children must function differ substantially from adults. Adult research findings on how experimental sleep deprivation affects truck drivers, medical residents, or other professionals are important, but these findings provide only a rough guess as to the effect of chronic sleep restriction on classroom behaviors or learning, the development of new driving skills, or behavioral and social functioning in developing children.

Studying children and adolescents poses methodological challenges. The primary research design for adult sleep deprivation studies, in which participants stay in lab to allow for greater control of sleep and activity schedules, is less of an option for child researchers because parents are often reluctant to leave their children in the care of unfamiliar adults, participants may be resistant to a prolonged stay away from home, and children’s sleep may be particularly subject to disruption in an unfamiliar environment. Further, children are a vulnerable population, for whom additional protections against risk may be required. Although it seems that any health effects of short-term sleep restriction are reversible with 1 to 2 nights of recovery sleep, researchers must consider the risk of events that could occur during sleep restriction (eg, a poor school grade, auto accident for young drivers) and attempt to mitigate that risk. As a result, there have been few experimental studies.

High-quality studies using multiple research designs are needed because each has strengths and weaknesses. Correlational, case-control, and quasi-experimental studies lend themselves well to assessing the real-world associations between sleep and daytime function, often in impressively large samples that promote subgroup analyses and generalization of findings. However, the potential for uncontrolled confounding factors (eg, parent work schedules, parenting styles, family structure, child daytime activities/habits, teen employment) limits causal inferences, and measurements of both sleep and outcome variables are often imprecise. In contrast, experimental studies allow for more confident attribution of causality and more measurement precision, but the conclusions can be limited by small samples and by methods and measures that do not map cleanly onto real-world circumstances.

Like research designs, different cognitive and behavioral assessment techniques have complementary strengths and weaknesses. Questionnaires have the advantages of easy administration, low cost, and ready assessment of real-world functioning, but are prone to reporter biases. Office-based standardized neuropsychological tests avoid such bias and can parse out specific cognitive skills. However, some domains of functioning, particularly attention and executive functioning (eg, planning, organization, mood, and behavior regulation), are difficult to assess in an office-based testing environment. Direct systematic rating of child behaviors by trained observers can provide an objective perspective in applied settings but is logistically very difficult; the 2 studies that have used such techniques in the sleep-behavior literature used simulated classrooms rather than embedding raters in subjects’ schools.

In the end, there is no single best way to study the effect of sleep on the daytime functioning of children and adolescents. The best conclusions tend to be drawn from an accumulation of studies with complementary strengths and weaknesses.