Normative sleep duration in adolescence and young adulthood: National data from the add health study

Sleep is essential for mental and physical health and well being. Recent reports have provided US national epidemiological data on sleep duration in children and middle-aged adults, but no such data have been presented for adolescence and young adulthood. Documented biological mechanisms such as adolescent sleep phase delay and social and contextual factors such as early school start times in adolescence and transition into adulthood roles in the 20s provide reasons to expect that sleep duration is developmentally patterned during this period of the lifespan. Normative data on sleep duration during this period are needed to describe age-related variation in sleep duration and provide a basis for additional research on the precursors and consequences of sleep duration during this life period. This study presents normative data on self-reported sleep duration from adolescence through young adulthood (ages 12-32) using longitudinal, nationally representative data from Waves 1-4 of the National Longitudinal Study of Adolescent Health (N=21,334). Age curves were estimated using multilevel modeling; piecewise linear regressions were used to estimate slopes in each of three developmental periods: adolescence (ages 12-18), post-high school (ages 18-21), and early adulthood (ages 21-32). Analyses revealed clear developmentally patterned effects. Sleep duration was highest at age 12 (8.7 hours per night), declined steeply to its lowest levels at age 18, 7.4 hours (B=-.22, SE=.01, p<.001), increased steeply through age 21 to 8.2 hours (B=.30, SE=.02, p<.001), and gradually declined through age 32 to 7.8 hours (B=-.025 SE=.01, p<.001). Additional social, demographic, and biological correlates of sleep duration are discussed.