Sufficient sleep is critical for adolescent health, yet the number of hours slept per night has decreased significantly among teenagers in the United States over the last 20 years, according to a new study by researchers at Columbia University’s Mailman School of Public Health.
While teens overall are sleeping less, the researchers 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 online in the journal Pediatrics.
For the study, the researchers analyzed data from Monitoring the Future – a nationally representative annual survey of adolescents in the US running from 1991 to 2012. The survey captured information for a total of 272,077 adolescents.
Students who were in the 8th, 10th and 12th grades reported how often they got 7 or more hours of sleep. Those who reported sleeping this amount “every day” or “almost every day” were categorized as obtaining that amount of sleep regularly, in contrast to those who “sometimes,” “rarely” or “never” slept for that amount of time.
Minority and low-SES students may underestimate need for sleep
Adolescent sleep declined over the 20 years recorded by the survey. The largest decrease in the number of adolescents getting 7 or more hours of sleep every night was among 15-year-olds. In 1991, 72% of this age group regularly got 7 or more hours of sleep, and by 2012, this figure had fallen to 63%.
Female students, racial and ethnic minorities and students with a lower socioeconomic background were more likely to obtain less than 7 hours of sleep compared with male students, non-Hispanic white students and students from a higher socioeconomic background.
The researchers note that although adolescents from racial and ethnic minority groups and families with little formal education were less likely to report getting 7 or more hours of sleep, they were also more likely to report getting adequate levels of sleep. The authors say that this finding suggests 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,” says Dr. Katherine W. Keyes, the study’s lead author.
Reported declines in sleep ‘warrant interventions’
For all adolescents, the biggest declines in sleep were reported between 1991-1995 and 1996-2000. However, the disparity in the amount of sleep obtained according to race has increased more recently.
Although the underlying reasons for the decreases in hours of sleep are unknown, Dr. Keyes says factors such as increased internet and social media use and the heightened competitiveness of the college admissions process are likely adding to the problem.
According to the National Sleep Foundation (NSF), teenagers function best obtaining 8-10 hours of sleep every night. Without adequate levels of sleep, adolescents can find their abilities to think and reason impaired and become more prone to mood swings and pimples. Lack of sleep is also associated with mental health issues, weight gain, academic problems and substance abuse.
The observed racial, gender, and SES inequities in sleep are particularly troubling, as they could contribute to future disparities in diseases like obesity, diabetes, and heart disease.
“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,” concludes Dr. Keyes.