Average nightly sleep times precipitously decline from childhood through adolescence. There is increasing concern that historical shifts also occur in overall adolescent sleep time.
Data were drawn from Monitoring the Future, a yearly, nationally representative cross-sectional survey of adolescents in the United States from 1991 to 2012 (N = 272 077) representing birth cohorts from 1973 to 2000. Adolescents were asked how often they get ≥7 hours of sleep and how often they get less sleep than they should. Age-period-cohort models were estimated.
Adolescent sleep generally declined over 20 years; the largest change occurred between 1991–1995 and 1996–2000. Age-period-cohort analyses indicate adolescent sleep is best described across demographic subgroups by an age effect, with sleep decreasing across adolescence, and a period effect, indicating that sleep is consistently decreasing, especially in the late 1990s and early 2000s. There was also a cohort effect among some subgroups, including male subjects, white subjects, and those in urban areas, with the earliest cohorts obtaining more sleep. Girls were less likely to report getting ≥7 hours of sleep compared with boys, as were racial/ethnic minorities, students living in urban areas, and those of low socioeconomic status (SES). However, racial/ethnic minorities and adolescents of low SES were more likely to self-report adequate sleep, compared with white subjects and those of higher SES.
Declines in self-reported adolescent sleep across the last 20 years are concerning. Mismatch between perceptions of adequate sleep and actual reported sleep times for racial/ethnic minorities and adolescents of low SES are additionally concerning and suggest that health education and literacy approaches may be warranted.