According to one study, teens sleep 43 minutes more per night after taking two treatments

A study from the Stanford University School of Medicine found that teenagers slept another 43 minutes a night after a four-week intervention, which allowed them to reset and go to bed earlier.

There were two components to the treatment: short, bright, broad-spectrum morning lightning to reset circadian clocks for adolescents, and cognitive-behavioral therapy that encouraged them to try sleeping earlier. The results will be published online on September 25 in JAMA Network open now.

"By using passive light therapy during sleep, we can help teens sleep 43 minutes more each night," said lead author Jamie Zeitzer, Ph.D., associate professor of psychiatry and behavioral science .

The light was transmitted by a device installed in the teenagers' room, programmed to emit flashes of 3 milliseconds every 20 seconds during the last hours of sleep. The brief flashes of light did not wake the teens. Zeitzer's earlier research on jet lag had shown that exposure to short flashes of light could cause the brain to adapt to a new time zone even during sleep.

Chronic sleep deprivation is common among teens, Zeitzer said. The circadian body clock, which controls the daily rhythms of sleep and waking, is naturally adjusted later in adolescents than in children or adults, which means that adolescents often sleep late at night. Teens can also stay awake late due to social influences such as homework and the use of electronic devices. Early school hours often require them to wake up before being fully rested, further contributing to sleep deprivation.

Previous studies have investigated whether cognitive behavioral therapy alone can help adolescents fall asleep earlier. The successes were modest: after the treatments, the teenagers fell asleep 10 to 15 minutes earlier, on average. But these interventions might have put participants at odds with their own biological clock, asking them to try to fall asleep before getting tired, a behavior difficult to maintain, Zeitzer said.

"We have a biological desire to stay awake a few hours before going to sleep," he said. "Our team was therefore asked if we could adjust the circadian timing, asking teens to move their brains to Denver while they were living in California."

In the first four weeks of the new study, the researchers tested light therapy in a group of 72 adolescents. For four weeks, half of the participants were exposed to frequent lightning flashes during the last three hours of their normal sleep period. The remaining participants received a fictitious light therapy treatment consisting of three flashes of light per hour – too little to reset their body clocks.

Although light therapy more fatigued adolescents exposed earlier in the night, they remained awake late. Using light alone was not enough to increase the time spent sleeping.

"We had to convince teens to try to sleep earlier," Zeitzer said.

For example, during the second phase of the four-week study, researchers recruited 30 adolescents; half of them received light therapy during their last two hours of sleep and the other half, a simulated light therapy.

But in this phase of the study, all teens also participated in four one-hour sessions of cognitive-behavioral therapy to encourage them to fall asleep earlier. Therapists worked with each teenager to identify areas of their life that interested him. It would be better for him to sleep longer – such as academics, his physical appearance or his sports performance – and use them to motivate teens. Cognitive-behavioral therapy also included information on the body clock, sleep hygiene and strategies for waking up earlier on weekends.

In addition to the extra sleep, participants who received both light therapy and cognitive-behavioral therapy went to bed on average 50 minutes earlier than participants receiving only cognitive-behavioral therapy. In addition, participants receiving both therapies were six times more successful than those receiving only cognitive-behavioral therapy to maintain a uniform bedtime.

Previous studies on light therapy aimed at resetting the circadian clock have shown that morning bursts of light should continue every day to be effective, Zeitzer said. "The coolest part, for an intervention that teens should potentially live for years, is that it's completely passive.We install the flashing lamp in the person's room and place it on a timer; should not wear a device, do not forget to turn it on or do something else. "

The flashing light used in the study was a programmable bridge beacon; it's not marketed as a sleep aid, Zeitzer said.

The next step, he said, is how best to implement a short-term cognitive-behavioral therapy to improve sleep time for a large number of people.