The negative effects of insufficient sleep in children and adolescents are well documented. Sleep loss and daytime sleepiness impact school performance, health, and behavior. Despite the increasing awareness of the public health impact, major gaps remain in our understanding of adolescent sleep and daytime sleepiness. Currently the Centers for Disease Control and National Sleep Foundation recommend 8.5-9.5 hours of sleep for 10-17 year olds. These guidelines are based on data showing that sleep propensity is stable or even increases across adolescence. However, sleep propensity studies do not address the effects of sleep restriction on daytime functioning. Most studies that have attempted to establish the effects of sleep duration on daytime performance in adolescents have correlated poor performance to poor sleep habits rather than experimentally manipulating prior sleep duration. Moreover, no study has evaluated how the effects of sleep restriction change with age across adolescence. The longitudinal study proposed here will use a within-subject dose-response design to examine the maturational trajectory of sleep need as determined by the relation of experimentally varied sleep duration to daytime functioning and sleepiness. Eighty participants will enter the study between 10 and 14 years of age and be studied for 4 years. Thus, the longitudinal study will cover ages 10 to 18 years. Daytime performance and daytime sleepiness will be measured on separate occasions following four nights with time in bed restricted to 7, 8.5, or 10 hours. Annually all participants will complete the 3 different slee duration conditions within a 3 month period. Daytime performance as well as daytime sleepiness will be measured in laboratory testing sessions. Performance on a simple vigilance task and a more complex cognitive task will be evaluated. Daytime sleepiness will be measured objectively using the same multiple sleep latency test that forms the basis of the Centers for Disease Control adolescent sleep guidelines. Daytime sleepiness will also be measured objectively with theta and alpha electroencephalogram activity, and subjects will subjectively rate their sleepiness and mood. Our previous longitudinal study established that slow wave EEG activity during non-rapid eye movement sleep declines steeply between ages 12 and 16 years of age. The proposed study will determine if the age trajectories of the relations between sleep duration and performance or sleepiness are associated with the adolescent brain maturation reflected in the slow wave EEG decline. Age related circadian changes, determined by actigraphy during a week when subjects keep their habitual sleep scheduled, will be controlled for statistically in the evaluation of maturational changes in the performance vs. sleep duration dose-response curve. The results of this proposed project will provide the first longitudinal dose-response data measuring changes in sleep need across adolescence allowing more informed recommendations for adolescent sleep hygiene.
Insufficient sleep in children and adolescents is associated with impaired school performance and health and behavior problems. The proposed project will fill gaps in our understanding of adolescent sleep by determining how sleep need changes across the teenage years. Sleep need will be evaluated in laboratory experiments measuring daytime performance and daytime sleepiness following 4 nights with sleep duration restricted to 7, 8.5, or 10 hours.