Get Enough Sleep

Most teens require more than nine hours of sleep. But unlike people of other ages, teens naturally tend to stay up later at night. In general, teens have trouble falling asleep before 11 pm. During adolescence, their internal clock, known as circadian rhythm, shifts them in that direction. Some normally stay up even later. Still, they must awaken relatively early to attend school and/or work at their jobs. As a result, teens may easily have a chronic sleep shortage. It is not uncommon for them to yawn and even fall asleep during the school day. According to an article published in 2014 in Pediatric Nursing, 87 percent of teens do not obtain adequate amounts of sleep. ²

In a study published in 2012 in the Journal of School Health, researchers from Hong Kong examined the association between sleep patterns, naps, and sleep disorders and the academic performance of students. The cohort consisted of 22,678 students between the ages of 12 and 18 years. They all completed questionnaires on various characteristics, including sleep patterns and academic performance. The researchers learned that during regular school nights only 27.4 percent of the students slept more than eight hours. On the other hand, during non-school nights, 86.4 percent of the students slept more than eight hours. The researchers found an association between late weekend bedtimes and poor academic performance. After-school naps and insufficient sleep also appeared to be associated with poor academic performance. At the same time, delays in awakening on the weekend improved academic performance. The researchers advised students with academic performance problems to “seek medical advice for maintaining a better health-related lifestyle including sufficient rest time.” ³

In a study published in 2013 in the Journal of Adolescent Health, researchers from Birmingham, Alabama, noted that each year over 8,000 American teens between the ages of 14 and 15 years require medical attention as a result of a pedestrian injury. The researchers wondered if the lack of sleep placed teens at increased risk for these injuries. The cohort consisted of 55 teens between the ages of 14 and 15 years. After one night of four hours of sleep and another night of 8 1/2 hours of sleep, these teens participated in a virtual reality pedestrian environment, which “replicated a two-lane, bidirectional, mid-block street crossing near a local elementary school.” Caffeine consumption, which could alter levels of fatigue, was prohibited during those mornings. The teens completed 25 trials while sleep restricted and 25 trials while adequately rested. The results were dramatic. Compared to a night of adequate sleep, following a night of restricted sleep, the teens took more time to begin crossing the street, had less time before contact with vehicles, had more close calls or actual virtual hits, and looked right and left more often. The researchers commented that “inadequate sleep may influence cognitive functioning to the extent that pedestrian safety is jeopardized among adolescents capable of crossing streets safely when rested.” ⁵

In a study published in 2014 in the Journal of Clinical Sleep Medicine, researchers from Virginia and Texas examined the association between the times that teens begin their school day and rates of car crashes. From their earlier research on the topic, the researchers hypothesized that the schools that began their day earlier would have more teens in car crashes. Those teens would need to awaken earlier. The researchers obtained their data on weekday crashes in 16- to 18-year-old teens as well as adults from the Virginia Department of Motor Vehicles. The researchers compared data from Chesterfield County, which starts school 85 minutes earlier, with data from Henrico County, which has a later starting time. As they expected, the researchers found teens who were traveling to schools with the earlier starting times had statistically significant higher rates of crashes. The researchers noted that their findings “adds to the body of research that suggests that early high school start times may be disadvantageous for teen driving safety.” ⁶

In an article published in 2013 in Health Services Insights, researchers from the University of Rhode Island noted that the use of cellular phones among teens has emerged as an “important factor” that is interfering with both the quality and quantity of teen sleep. Use of phones among teens has grown astronomically; according to these researchers, it is not uncommon for teens to send 100 texts per day. In addition, teens often use phones in bed before falling asleep. As a result, their ability to fall asleep and remain sleeping may be compromised. For example, they may awaken to answer text messages. Moreover, “emerging research points to the prevalence of patterns of problematic phone use among adolescents that are akin to behavioral addiction.” Thus, it is very difficult to restrict or “place boundaries” on the phone use of teens. The researchers advised medical providers to ask teens candid questions about their sleep practices. And, if appropriate, medical providers should discuss the importance of establishing boundaries between sleep and phones. “Given the importance of sleep on growing minds and bodies, any efforts to improve adolescent sleep quantity and quality should be considered a worthwhile investment.” ⁸

In a study published in 2014 in the International Journal of Environmental Research and Public Health, researchers from China investigated the impact that screen viewing devices, such as phones and personal computers, have on sleep duration, sleep quality, and daytime sleepiness among Hong Kong adolescents.

According to these researchers, while the American Academy of Pediatrics recommends that screen viewing time be no more than one to two hours per day, “screen viewing has becomes a crucial activity in the everyday life of adolescents.”

The cohort consisted of 762 teens who ranged in age from 12 to 20 years, with a mean age of 15.27 years. Sleeping assessments were made using the Chinese version of the Sleep Quality Index, and the teens reported the exact amount of time that they spent viewing televisions, computers, portable devices, and mobile phones. While the teens noted that they slept an average of 7.74 hours per night, 414 teens or 55.6 percent reported sleeping less than 8 hours per night. At the same time, the teens said that they used screen devices an average of 5 hours 54 minutes per day. The researchers found no association between watching television and any of the sleep variables, and the only sleep variable associated with computer viewing was daytime sleepiness. Similarly, portable devices were only related to sleep duration. On the other hand, mobile phone viewing was correlated with all three sleep variables. Why are these findings so important? According to the researchers, obtaining adequate quality sleep is a crucial component of a successful adolescence. That is why “determining the recommended level of screen viewing among adolescents is a matter of public health.” ⁹

In a study published in 2014 in the Journal of Adolescence, researchers from Australia noted that video-gaming is incredibly popular among teens in the United States, with more than three-quarters of all children and teens playing them every week. They wanted to learn more about the association between the use of video games before bedtime and subsequent sleep, working memory (short-term memory), and sustained attention performance. Their cohort consisted of 21 healthy teens (16 males) between the ages of 15 and 20 years. All of the teens were considered “good sleepers.” During a one-night stay in the sleep laboratory, a number of different measurements were taken. The researchers learned that, on average, the participants spent four hours gaming in one pre-bedtime session and obtained slightly less than seven hours of sleep. Males spent significantly more time gaming and obtained significantly less sleep. They slept less because they spent so much time gaming, not because they had a problem falling asleep. Because gaming reduced the number of hours slept, it diminished sustained attention in the morning, but not working memory. The researchers noted that their findings “highlight the potential performance deficits associated with evening gaming, especially if repeated on consecutive nights, which may have important consequences in domains such as school achievement and accident risk.” To mitigate these problems, “video games should be used in moderation and not too close to the sleep period.” ¹⁰

1. National Sleep Foundation, http://sleepfoundation.org.

2. Shirley A. Wiggins and Jackie L. Freeman, “Understanding Sleep During Adolescence,” Pediatric Nursing 40, no. 2 (2014): 91-98.

3. K-K. Mak, S-L Lee, S-Y Ho et al., “Sleep and Academic Performance in Hong Kong Adolescents,” Journal of School Health 82, no. 11 (2012): 522-27.

4. Mari Hysing, Siren Haugland, Kjell Morten Stormark et al., “Sleep and School Attendance in Adolescence: Results from a Large Population-Based Study,” Scandinavian Journal of Public Health 43, no. 1 (2015): 2-9.

5. Aaron L. Davis, Kristin T. Avis, and David C. Schwebel, “The Effects of Acute Sleep Restriction on Adolescents’ Pedestrian Safety in a Virtual Environment,” Journal of Adolescent Health 53 (2013): 785-90.

6. Robert Daniel Vorona, Mariana Szklo-Coxe, Rajan Lamichhane et al., “Adolescent Crash Rates and School Start Times in Two Central Virginia Counties, 2009-2011: A Follow-Up Study to a Southeastern Virginia Study, 2007-2008,” Journal of Clinical Sleep Medicine 10, no. 11 (2014): 1169-1177E.

7. Duan-Rung Chen, Khoa D. Truong, and Meng-Ju Tsai, “Prevalence of Poor Sleep Quality and Its Relationship with Body Mass Index Among Teenagers: Evidence from Taiwan,” Journal of School Health 83, no. 8 (2013): 582-88.

8. Sue K. Adams, Jennifer F. Daly, and Desireé N. Williford, “Adolescent Sleep and Cellular Phone Use: Recent Trends and Implications for Research,” Health Services Insights 6 (2013): 99-103.

9. Yim Wah Mak, Cynthia Sau Ting Wu, Donna Wing Shun Hui et al., “Association Between Screen Viewing Duration and Sleep Duration, Sleep Quality, and Excessive Daytime Sleepiness Among Adolescents in Hong Kong,” International Journal of Environmental Research and Public Health 11, no. 11 (2014): 11201-19.

10. Jasper Wolfe, Kellyann Kar, Ashleigh Perry et al., “Single Night Video-Game Use Leads to Sleep Loss and Attention Deficits in Older Adolescents,” Journal of Adolescence 37 (2014): 1003-9.

11. Tim S. Olds, Carol A. Maher, and Lisa Matricciani, “Sleep Duration or Bedtime? Exploring the Relationship Between Sleep Habits and Weight Status and Activity Patterns,” SLEEP 34, no. 10 (2011): 1299-307.