title: Developmental trends in sleep duration in adolescence and young adulthood: evidence from a national United States sample.
abstract: OBJECTIVE
  To present normative values of mean sleep duration from adolescence through young adulthood (ages 13-32 years), prevalence of short (<6 hours) and long (>10 hours) sleep durations, and differences in each by sex and race/ethnicity.
  
  
  METHODS
  Mean sleep duration and prevalence of extremely short and long sleep were estimated using data from the United States National Longitudinal Study of Adolescent Health, Waves 1-4 (N = 15,701).
  
  
  RESULTS
  Sleep duration showed age-related trends, with decreases across the adolescent period from 8.5 hours per night at age 13 years to 7.3 hours at age 18 years, an increase through the emerging adulthood period to 8.5 hours at age 22, and a gradual decline across early adulthood to 7.7 hours at age 32 years. Prevalence of extremely long and short sleep followed similar developmental trends. Adolescent girls reported lower mean sleep duration than did boys, but women reported longer average sleep duration than did men from age 19 years onward. Short sleep duration was most common among African-Americans at all ages. Long sleep was most common among African-Americans in adolescence and emerging adulthood and among Hispanics in early adulthood.
  
  
  CONCLUSIONS
  Sleep duration is developmentally patterned from adolescence through early adulthood. Mean and extreme sleep durations vary systematically by sex and race/ethnicity as well as age. These normative data on sleep duration will inform studies of the role of sleep in the etiology of a wide range of health conditions affecting adolescents and young adults.
authors.affiliation: Robert Wood Johnson Foundation Health & Society Scholars Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin. Electronic address: maslowsky@wisc.edu.
authors.forename: Julie
authors.initials: J
authors.lastname: Maslowsky
authors.affiliation: Division of Community Health and Human Development, School of Public Health, University of California-Berkeley, Berkeley, California.
authors.forename: Emily J
authors.initials: EJ
authors.lastname: Ozer
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000502:physiology; D000328:Adult; D000367:Age Factors; D005006:Ethnicity / Q000706:statistics & numerical data; D005260:Female; D006306:Health Surveys / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D015995:Prevalence; D044469:Racial Groups / Q000706:statistics & numerical data; D017678:Sex Distribution; D012890:Sleep / Q000502:physiology*; D012893:Sleep Wake Disorders / Q000453:epidemiology*; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D055815:Young Adult
keywords: Adolescence; Norms; Sleep; Young adulthood