Columbia University. US: Sufficient sleep is critical for adolescent health, yet the number of
hours slept per night has decreased among teenagers in the United
States over the last 20 years. A study by researchers at Columbia University’s Mailman School of Public Health found
that female students, racial/ethnic minorities, and students of lower
socioeconomic status are particularly affected, with teens in these
categories less likely to report regularly getting seven or more hours
of sleep each night compared with their male counterparts, non-Hispanic
white teenagers, and students of higher socioeconomic status,
respectively.
Findings from “The Great Sleep Recession: Changes in Sleep
Duration Among U.S. Adolescents, 1991-2012” are published in Pediatrics.
The study is the first comprehensive evaluation of recent sleep trends by age and time period for U.S. adolescents.
Students in the 8th, 10th and 12th grades of a nationally
representative survey of more than 270,000 adolescents from 1991 to 2012
reported how often they get seven or more hours of sleep.
The proportion of adolescents who regularly got seven hours of sleep
was defined as a frequency of every day or almost every day versus
sometimes, rarely, or never. The survey did not control for weekday
versus weekend wake-up and sleep times.
Racial/ethnic minorities and those whose parents had little formal
education said they were less likely to regularly get seven or more
hours of sleep, yet they were more likely to report getting adequate
sleep, suggesting a mismatch between actual sleep and perceptions of
adequate sleep.
“This finding implies that minority and low socioeconomic status
adolescents are less accurately judging the adequacy of the sleep they
are getting,” said Katherine M. Keyes, PhD, assistant professor of Epidemiology at the Mailman School of Public Health and lead author.
The largest decrease in the percentage getting seven hours of sleep
per night was 15-year-olds, a particularly concerning trend for a
significant portion of U.S. students at this important juncture in
development. Among this age group, 72 percent reported regularly getting
seven-plus hours of sleep per night in 1991; by 2012, in the same age
group, 63 percent of adolescents reported regularly receiving seven or
more hours of sleep per night. The largest declines for all adolescents
occurred between 1991 and 1995 and 1996 and 2000. The disparity
according to race has increased in more recent time periods.
Seven hours per night is two hours less than the nine hours
recommended by the National Sleep Foundation. Inadequate sleep is
associated with a wide range of health problems including mental health
issues, academic problems, substance abuse, and weight gain.
“Although the underlying reasons for the decreases in hours of sleep
are unknown, there has been speculation that increased Internet and
social media use and pressures due to the heightened competitiveness of
the college admissions process are adding to the problem,“ noted Dr.
Keyes. “Declines in self-reported adolescent sleep across the last 20
years are concerning and suggest that there is potentially a significant
public health concern that warrants health education and literacy
approaches.”
Co-authors are Julie Maslowsky, University of Texas; Ava Hamilton,
Columbia University’s Mailman School of Public Health,; and John
Schulenberg, University of Michigan.
The study was supported by the Robert Wood Johnson Foundation Health
& Society Scholars Program, National Institute on Drug Abuse (R01
DA001411), National Institute on Alcoholism and Alcohol Abuse (K01
AA021511) and National Institutes of Health. The authors report no
conflicts of interest.