After many years of neglecting sleep's importance in our lives, we've entered a golden age of sleep studies. We now know that sleep plays a central role in everything from creativity to memory consolidation, and that sleep deprivation, in addition to being associated with a range of debilitating conditions, can leave us with the same cognitive capacity of someone legally drunk.
Christian Benedict is helping lead this scientific movement. A neuroscientist at Uppsala University in Sweden, Benedict has particularly focused on how sleep is connected to performance in school. And as this incontrovertible science piles up, more and more schools are taking note in ways that can really make a difference in young people's lives. In answer to my questions, Benedict shared his insights on the importance of understanding young people's sleep patterns, how school start times may be a bigger factor in student success than previously thought and simple tips to help adolescents get a truly good night's rest.
You've researched the link between lack of sleep and failure at school. What did you find?
Studies have shown that sleep supports a variety of functions that children require to perform well at school. For instance, sleep was demonstrated to promote university students' ability to solve mathematical problems. Sleep is also integral to the consolidation of newly learned declarative (e.g., facts) and procedural (e.g., playing a piano piece) memories. Finally, restful slumber is a prerequisite for your brain to work at full capacity during the day. With this in mind, my sleep group at Uppsala University, Sweden, sought to investigate if self-reported sleep problems are linked to academic success at school.
To this aim, we utilized survey data involving more than 20,000 Swedish adolescents aged between 12 and 19. This survey involved questions related to the adolescents' habitual sleep duration and sleep disturbances (e.g., problems falling and/or staying asleep), as well as their performance at school. One important finding of our study was that about 30 percent of the adolescents reported sleep problems; that means either sleep disturbances or sleep duration less than seven or eight hours per night. In my view the latter finding is quite alarming, since adolescents are typically recommended to sleep between nine and 11 hours per night (e.g., by the U.S. National Sleep Foundation). We also demonstrated that reports of sleep disturbance and habitual short sleep duration were associated with an increased risk of failure at school, as measured by the number of failed subjects during the school year, supporting the view that restful slumber, of sufficient duration, matters for a child's academic performance.
Which age group has the biggest risk of poor academic performance linked to poor sleep?
Humans have individual differences in the timing of their behaviors (e.g., preferred working hours, sleeping habits). At one extreme are the so-called morning types (larks), at the other extreme the evening types (owls). During puberty most adolescents tend to shift toward being evening types and, as such, do not have the feeling "Now it is time to go to bed" before late evening hours (e.g., 11 p.m. to 1 a.m.). Typical school start times in many countries are at 8 a.m. or even earlier, which means that adolescents must get up around 6 or 7 a.m. This means the adolescent owls are predisposed to run the biggest risk of being short on sleep and, accordingly, to perform poorly at school.
What changes can be made to reduce the risk of students failing out of school because of poor sleep?
One intervention to give all high school students equal academic opportunities could be delaying school starting times and delaying all examinations until the early afternoon. Supporting this view, a recent study involving 741 Dutch high school students ages 11 to 18 years revealed that the lowest grades were obtained by students who were used to going to bed late.
How would you advise educators and parents to help students struggling with sleep?
In addition to delaying school starting times and scheduling examinations in the afternoon, one possibility to help students struggling with sleep would be for educators to increase parental awareness of the importance of sleep for their child's ability to perform at full capacity (e.g., by means of parent-teacher conferences). In addition, there are several recommendations that may facilitate an adolescent's ability to fall and stay asleep:
- Avoid caffeine (found in carbonated beverages, coffee and dark chocolate, for example) in the evening.
- Switch off blue-light-emitting devices about one hour before bedtime. The use of electronic devices able to access the Internet (e.g., tablets, smartphones and LED screens) close to bedtime may also cause sleep problems, as they can emit blue light, which was shown to suppress the release of the sleep-promoting hormone melatonin and alter sleep quality.
- Be physically active three to four hours before bedtime.
- Dim room light 30 to 60 minutes before bed.
- Your bed is a place for sleep, not for work.
- Reduce environmental noise exposure.
- Consult a medical doctor if you snore. It may indicate that you are at increased risk for poor-quality sleep.
- Empty your bladder before going to bed, and avoid drinking too much before sleep.