Image for sleep deprivation Sleep deprivation can be summed up as a chronic lack of adequate sleep. Too little sleep—even one hour less a night—develops over time into a sleep debt. This sleep debt can accumulate and is only wiped out when enough sleep is obtained. And sleeping more on weekends may not completely erase the debt. Switching back and forth from late hours on weekends to early hours on weekdays may even exacerbate the problem.

If sleep debt becomes too great, it causes sleepiness and can negatively affect performance, concentration, reaction time, memory, mood, and behavior control. A teen’s physical growth can even be affected by a chronic lack of sleep, since growth hormone is most active during sleep.

Teens need about nine hours of sleep per night, yet on average get around seven hours. Not getting enough sleep is only part of the problem, as sleep patterns also change during adolescence. Changes related to puberty cause the sleep hormone melatonin to be released later in the day, which alters the circadian rhythms and, in turn, the sleep-wake cycle. The result is teens fall asleep later and wake up later. While this altered schedule is recognized as a normal part of puberty, it has not changed the fact that many middle and high schools have early start times, cutting into possible sleep time.

One of the most troubling effects of sleep deprivation is a drop in memory and attention, making learning more difficult and negatively impacting school performance.

In a study published in Child Development, researchers studied the sleep habits of 3,120 high school students. They then compared sleep habits to mood, school performance, and behavior. They found that struggling students went to bed 40 minutes later and had 25 fewer minutes of sleep than the students earning better grades. The students who got less sleep also experienced increased sleepiness during the day, depressed mood, and behavior problems. Even this small difference in sleep seemed to affect the way adolescents functioned during the daytime.