Lack of sleep increases risks for injury
If you're a parent, you know that lack of sleep can make your teen grouchy and distracted, irritable and low energy. Did you know that insufficient sleep also puts teenagers at greater risk for injury?
Scientists at the Centers for Disease Control investigated the link between sleep duration and injury-risk related behaviors in high-school students in the United States. They found that students who reported sleeping less than seven hours a night on school nights were significantly more likely to also report engaging in a number of behaviors linked to injury risk, compared to students who reported sleeping nine hours on school nights.
Less sleep, more injury risk for teens
There's already compelling scientific evidence that lack of sleep in adolescents puts them at greater risk for injury. Recent studies indicate:
• Teen athletes who don't sleep enough are more likely to suffer sports injuries. Scientists found that teenage athletes who slept less than eight hours nightly were 1.7 times more likely to have suffered an athletic injury than those student-athletes who slept eight hours or more a night.
• Adolescents are more likely to experience work-related injuries when they are short on sleep. A 2015 study examined the link between occupational injury and sleep among teenagers in Washington state. Among teens who worked, those who slept no more than five hours a night on school nights were nearly three times as likely to have experienced on-the-job injuries than working teens who slept eight hours or more on school nights.
• Teens and young adult drivers who are sleep deprived are at significantly higher risk for motor-vehicle accidents. Young drivers who slept six hours or less a night have a greater risk for being involved in motor-vehicle crashes than young drivers who sleep more than six hours.
In the current study, CDC researchers investigated how sleep duration on school nights affected five common risk behaviors that can lead to injury:
• Infrequent bicycle helmet use
• Infrequent seatbelt use
• Riding with motor-vehicle drivers who'd been drinking
• Drinking and driving
• Texting and driving
The scientists analyzed data from the Youth Risk Behavior Survey, a CDC survey that examines health-risk behaviors in children and teens nationwide. Researchers used data on 50,370 high-school students in grades 9-12. As part of their participation in the Youth Risk Behavior Survey, students answered questions about their sleep amounts on school nights, as well as questions about each of the five risk behaviors.
The analysis revealed that the majority of high school students surveyed were not meeting recommended sleep amounts for their age, and that their lack of sleep was linked to increases in each of the five risk behaviors investigated.
Let's take a look first at reported sleep amounts. The National Sleep Foundation recommends that adolescents ages 14-17 get 8-10 hours of sleep a night. Among the high-school students included in this study, less than a third--31.1percent -reported sleeping eight or more hours on an average school night.
• 30.1 percent reported sleeping seven hours a night
• 21.9 percent reported sleeping six hours nightly on typical school nights
• 16.8 percent reported sleeping five hours or less on an average school night
Overall, female high-school students were more likely to report insufficient sleep than male students.
• 71.3 percent of female students reported sleeping no more than seven hours on school nights, compared to 66.4 percent of male students
Students were more likely to report insufficient sleep in higher grades.
• 59.7 percent of ninth grade students reported sleeping no more than seven hours on an average school night
• 76.6 percent of twelfth grade students reported sleeping no more than seven hours on an average school night
Each of the five risk behaviors were reported significantly more often among students who slept seven hours or less a night. Several risk behaviors--infrequent seatbelt use, riding with drivers who'd been drinking, and drinking and driving--were also more likely among students who slept 10 or more hours a school night, compared to students who slept nine hours. Drinking and driving occurred more often in students who slept eight hours on an average school night, compared to those who slept nine hours.
The risks of poor sleep in teens
This study adds to the existing body of evidence that links insufficient sleep and other sleep issues to risky behaviors in teenagers. In addition to sleep duration, studies have demonstrated that irregular and inconsistent sleep patterns and reported sleep problems are associated with greater frequency of risky behavior in teens.
In addition to the injury-related risk behaviors examined in the current CDC study, other risk behaviors are linked to insufficient sleep and irregular sleep habits in teenagers. Among teens with these sleep issues, several other risky behaviors occur more frequently:
• Substance use, including alcohol, tobacco, and marijuana
• Physical inactivity
• Physical fighting
• Feelings of sadness
• Depression, anxiety, and other mood problems
• Contemplation of suicide
Lack of sleep, poor sleep quality and irregular sleep patterns are associated with negative consequences for nearly every aspect of adolescents' lives. In teenagers, sleep problems are linked to:
• Academic problems
• Other sleep problems
• Difficulty regulating emotions
• Depression, anxiety and other mood problems
• Health problems, including a greater risk for obesity and a greater risk for cardiovascular disease later in life
It's all too easy for teenagers to run up a sleep debt. Teens' schedules are often filled with sports and other extracurricular activities as well as social engagements. Late night homework sessions and early morning school start times make it difficult for teens to log a truly full night of rest. What's more, during adolescence, the body's circadian rhythms make a significant shift toward a later cycle, leading to a biologically driven preference to stay up later and rise later. These forces combined lead many teenagers to remain awake well after bed times that would ensure sufficient sleep, and to rise in the morning tired.
Improving sleep for teens
How can we help adolescents get the sleep they need? The fundamentals of strong sleep hygiene are critical for teenagers.
Encourage consistency. A regular sleep schedule is the centerpiece of a healthy sleep routine. That means bedtimes and wake times that are roughly the same throughout the week--and don't change significantly on weekends. Some sleeping in on Saturdays and Sundays is okay, but a drastic change to bedtimes and wake times on the weekend can disrupt their sleep schedule in the week ahead. Shoot to vary bedtimes and wake times by no more than an hour from weekdays to weekends.
Keep electronics out of the bedroom. The light from digital devices intrudes on the body's natural progression toward sleep, delaying the release of melatonin and shortening the sleep hormone's duration throughout the night. Moreover, the stimulation that these devices provide is detrimental to relaxation and rest. Create a charging station for phones, laptops, and tablets that is central, and away from teens' bedrooms. Keep televisions and any other screens out of the bedroom as well.
Lower lights around the house in the evening. Help reinforce sleep cycles by limiting artificial light exposure during the hours before bedtime. Use dimmer switches and adjustable lamplight to bring light levels down. Avoid having big-screen TVs blasting light (and sound) right up until bedtime. With their already delayed circadian cycles, teens are already predisposed to staying up late--and too much bright light in the evenings will reinforce that predisposition.
Encourage healthful eating and regular physical activity. A healthful, moderate, balanced diet supports high-quality sleep at any age, including during adolescence. Have teenagers avoid eating too heavily in the hours before bedtime. A light snack before bed is fine--going to bed hungry can interfere with sleep--but keep it small, and offer teenagers options that aren't packed with sugar and processed fats. Regular exercise can strengthen sleep cycles and enhance sleep quality as well as increasing sleep duration. This doesn't have to mean organized sports--any physical activity will contribute positively to sleep. Strive to have teenagers make physical activity of some kind part of their daily routine.
Helping teenagers learn to manage a healthy, sustainable sleep routine isn't always easy, but the benefits are abundantly clear. Avoiding insufficient sleep and other sleep problems is an investment in their health, their development, and their safety.
Michael J. Breus, PhD
The Sleep Doctor™