Dr. Greene, my son is 13 years old and I am wondering how much sleep he needs?

Parents are often concerned about the sleeping habits of their adolescent children. In my office, I commonly hear either "He sleeps past noon!" or "She's up all night!" (or both). Naturally, we want our children to be motivated and healthy. If it seems that they are sleeping their lives away, or that they are burning the candle at both ends, our parental instincts rise up.

The ideal amount of sleep at any given age varies widely between individuals, but adolescence is a particularly difficult age at which to pinpoint and ensure the proper amount of sleep.

Observations made in sleep laboratories (Carskadan, et al: Pubertal changes in daytime sleepiness. Sleep 2:453, 460, 1980) suggest that adolescents require more sleep than preteens. On the other hand, observations made in real life (Carskadan: Patterns of sleep and sleepiness in adolescents. Pediatrics 17:5, 1990) suggest that adolescents actually obtain much less sleep than they did during the preteen years.

A recent study suggests that 5% of adolescents meet criteria for chronic insomnia, and that sleep deprivation has negative effects on their physical & psychological health, interpersonal interactions, and ability to perform daily activities (Roberts et al: Chronic insomnia and its negative consequences for health and functioning of adolescents: a 12-month prospective study. J Adolesc Health, 2008).

This raises three important questions: First, is this data true? In other words, if researchers in a lab say one thing, and real life says another, are most teenagers really getting insufficient sleep? Second, if most teens do not get enough sleep, why? Are teens just shortsighted, stubborn and out of control? Third, what can be done to help teens get the sleep they need?

The contrast between ideal and actual sleep in teenagers is based on solid research. Its truth is bolstered by the additional observation that excessive sleepiness is a very common complaint among adolescents. Daytime sleepiness is the most common sleep-related disorder of adolescence.

For many years it was felt that the sleepiness of adolescents was their own fault. Their busy social agenda and burgeoning independence led to too many late nights. Recently, however, a different picture has emerged. Independent investigators in Brazil, Japan, and the United States (Andrade, et al; Ishihara, et al; and Carskadon, et al.) have suggested that the internal, biologic sleep-timing mechanism is reset along with the other changes of puberty. Their bodies signal them to go to sleep at a later hour and also to sleep later in the morning. They are often incapable of falling asleep earlier. Their school schedules, however, continue to force them out of bed at an early hour. This leads to a population of chronically sleep deprived adolescents.

Many teens are able to cope with chronic low-level sleep deprivation, often gaining some catch-up sleep by 'sleeping in' on the weekends. Others, however, fall asleep in school, have great difficulty getting out of bed in the morning, and/or experience great fatigue, emotional lability, irritability, poor impulse control, and poor decision making.

The average thirteen year old needs about 10 hours of sleep in a 24 hour period.