Sleepy students cannot focus in class. Monitor on Psychology found that the "overwhelming drive to sleep replaces any chance of alertness, cognition, memory or understanding."
Monitor on Psychology found that it's likely that "sleep deprivation and problems controlling impulses and emotions exacerbate one another, leading to a 'negative spiral' of fatigue and sleepiness, labile emotions, poor decision-making and risky behavior."
"Although research has amply demonstrated that sleep problems affect young people's cognitive skills, behavior and temperament," it is unknown if the damage is permanent according to Monitor on Psychology.
The New York TImes reported that sleep disturbances lasting longer than two weeks increase the risk of developing many psychiatric illnesses, especially depression.
Monitor on Psychology found that "adolescent sleep difficulties are often associated with psychopathologies," such as attention deficit hyperactivity disorder (ADHD).
Monitor on Psychology warns of teens driving while sleep deprived because "drowsiness and fatigue cause more than 100,000 traffic accidents each year--and young drivers are at the wheel in more than half of these crashes."