Christopher Merrill, 17, a varsity lineman for Scottsdale's Saguaro High School football team, dozed off so often that his mother mistakenly thought he was using drugs.

Drew Rostain, a senior at Chandler, Ariz., Hamilton High School, would stay up until 1:30 a.m. every night to fit in schoolwork, a job at a pizzeria and high school track and golf until he finally crashed and slept for a week straight.

The American Academy of Sleep Medicine says a third of the nation's teenagers don't get enough sleep, 40 percent have insomnia, up to 35 percent are sleepy all day and 50 percent have nightmares regularly. A recent survey by the National Sleep Foundation indicated only a fifth of teenagers get the nine or more hours of sleep doctors recommend.

Science is catching up with sleepy teens and spawning a growth industry for sleep centers.

Arete Sleep Health, a network that operates nine Arizona sleep centers and more than 20 nationwide, has increased its number of beds in the state to 52 from 16 since 2004, a sales executive said. The company aggressively markets its teen services to doctors, with the expectation of reaching a large patient group.

A sleep center at Scottsdale (Ariz.) Healthcare McDowell Mountain says that its number of teen sleep patients has doubled in the past five years and that its number of beds has risen by a third, though exact patient numbers are unavailable.

Doctors say teen sleep deficit is anchored in physiological change. Teachers gripe about sleep-depriving influences of the Internet and video games.

Parents, whose bedtimes often precede their teenage children's, are unsure what to make of the zombies in their midst.

TREATING SLEEPY TEENS

Doctors refer patients to sleep centers for a diagnosis and suggested treatment. A visit begins with a battery of questions about sleep habits.

"We talk about snoring, bedtimes, wake-up times, disturbances, eating, or whether they fall asleep during the day," says Dr. Steven Marks, Arete's Phoenix medical chief.

Sometimes, poor "sleep hygiene" is apparent, Marks says, and he makes behavioral suggestions such as keeping a regular bedtime, getting nine hours of sleep or turning off the television and computer. Some teens stay online all night connecting with friends, he says.

Truth is, the teen brain is wired to be sleepy.

Dr. Eric Benjamin, a psychiatrist who is chief of behavioral medicine at Phoenix Children's Hospital, says puberty triggers changes in brain chemistry that affect sleep. Newly occurring steroids and growth hormones turn sleep on and off at different times, he says.

Circadian rhythms, the daily 24-hour cycle that programs most living things, also change. Teenagers suddenly are geared to awaken later while the act of growing itself puts them in greater need of sleep.

Insufficient sleep can affect mood, performance and ability to learn.

It can be doubly damaging to teens because the growth hormones are produced during deep sleep. Lack of sleep can stunt growth.

"A certain number of teenagers become night owls," Benjamin says. "Some have trouble falling asleep, staying asleep or have trouble awakening in the morning. After a while, they aren't aware of it, but the problems can have a cumulative effect and can put them at risk."

Function becomes impaired, and kids get into trouble. More than half of the 100,000 U.S. car accidents caused annually by sleepy drivers involve teenagers.

School presents more challenges to the sleep-impaired.

"Some students come in, and immediately their heads go down," says teacher Phyllis Carr, chairwoman of the English department at Hamilton High School. "I may try to wake them up three or four times," she says. She typically taps the shoulders of four or five kids in each class but says all her students are groggy, echoing what many other teachers and high school students say.

WAKING UP TO SCIENCE

Merrill, the football player whose mom thought he was on drugs, was a chronic schoolroom snoozer.

"I'd fall asleep upright with a pencil in my hand," says Merrill, whose teachers mostly let him sleep. His grades plummeted, and his mother contacted an education consultant who thought his sleepiness was beyond typical.

Merrill was tested and diagnosed with sleep apnea, a syndrome more commonly associated with baby boomers who snore, where breathing stops because of an airway obstruction. The breather awakens hundreds of times a night but doesn't remember it in the morning. The condition is a precursor to heart attack and stroke.

Dr. Susan Madison, the doctor at the Sleep Disorders Center at Scottsdale Healthcare McDowell Mountain who treats Merrill, says more kids are getting sleep apnea, which is associated with being overweight or having large necks. Merrill's lineman's neck, bulked out from weight training, measures 18 inches around.

Merrill is following the adult protocol, treatment with an air pump called a CPAP, for continuous positive airway pressure. It keeps the airway from collapsing during sleep. He is scheduled to have tonsil surgery after the upcoming football season. Short of serious interventions like a CPAP, solutions for freeing teens from their sleep deficits can include drugs and behavioral therapy, after proper diagnosis.

Sleep experts and teachers say parents wield the most influence to help teenagers get on a sleep schedule and eliminate disruptions. Teacher Carr hears of students whiling away the wee hours on MySpace.com and speculates that the late-night stimulation can't be good for sleep.

Marks, the sleep doctor, says parents don't always do a good job of stressing the value of sleep. "There's an absence of guidance," he says.

Rick Rostain has been working with his son, Drew, on his sleep problem for a couple of months. They've gone to doctors and gotten tests ordered, but the father thinks the problem may be one of time management.

"Something's got to be done," Rostain says. "He needs to learn to cope in an adult world. That's why we wanted to find out."