Teens and Melatonin
As we have learned more about the chemistry of sleep in the past few decades, we have come to realize that it really is harder for teens, such as Jilly, to wake up early. In teens, melatonin is produced about three hours later in the 24-hour sleep cycle than in children or adults. This keeps them up late, and when they wake up early, SNAT is still active and they are still producing melatonin, which leaves them feeling sleepy in the morning.
Teenagers typically require nine hours of sleep per night. But because of their late bedtimes and schools’ early start times, they average only seven hours of sleep per night. Because they haven’t slept long enough, they feel perpetually drowsy, which affects their ability to pay attention in classes and to learn.
What happens when a high school, such as Jilly’s, starts later? So far, schools have reported big gains. For example, the Minneapolis Public School District shifted its start time from 7:15 a.m. to 8:40 a.m. It found that students averaged more than five extra hours of sleep each week, and attendance and enrollment rates improved as well. Also, daytime alertness increased, and rates of depression decreased.
Even more surprising is the number of car crashes involving teenagers in Fayette County, Kentucky, decreased by almost 17% in the two years following its adoption of a later start time for school. So, it appears that taking into consideration a shift in the timing of melatonin production in teens can have all sorts of benefits.
Many teenagers are not lucky enough to attend a school with a later start time, however. In the 2011–2012 academic year, about 40% of U.S. high schools were still starting before 8 a.m. So what can you do if you are in this group? First, minimize exposure to artificial light at night. This includes light from TV, computers, and phones. By signaling to your body that it is daytime, these light sources facilitate the degradation of SNAT and interfere with the production of melatonin. This means you won’t feel drowsy, making it difficult to go to sleep at a reasonable time.
Another way to get more sleep is to avoid sleeping in too late on weekends. It may seem counterintuitive because if you are not getting enough sleep during the week, your body will urge you to stay in bed on weekend mornings to make up for your lost sleep. But the reality is that sleeping in on weekends can confuse your body’s biological clock, making it even tougher to wake up on weekdays.