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It’s spreading. When one teenager starts sleeping less, her friends and others in her social circle soon lose sleep too.

Wikimedia Commons / Love Krittaya

Lack of Sleep Is Contagious

SAN DIEGO—Don’t get too close to a tired teen; you could start losing sleep as well. When one teenager starts sleeping less, her friends and others in her social circle soon lose sleep, too, according to new research presented here today at the annual meeting of the American Association for the Advancement of Science (which publishes ScienceNOW). This lack of sleep not only produces groggy high-school students but also can lead to drug use, the researchers reported.

Our social networks—the ones in real life and on Facebook—can influence our behaviors and moods. Political scientist James Fowler of the University of California, San Diego, has studied these effects and previously found that obesity, smoking, and even happiness can spread through networks of people solely based on their relationships.

Today, Fowler described his study of a network of more than 8000 seventh- to 12th-grade students and their sleeping and pot-smoking habits. He and colleagues mapped an entangled web of connections between each student and his or her friends. In one of these friend webs, a gang of sleepless boys dominated the middle of the jumble, where the most connected kids landed—the so-called “cool” kids. He and his colleagues found that the more central a teen landed on the map, the greater chance that he or she got less than 7 hours of sleep per night.

Drug use was also contagious, the team found. Each pot-smoking friend increased the chance that a student used marijuana by 42%. Both sleepless and drug-use contagions could still be felt four-degrees of separation away, influencing a friend of a friend of a friend’s friend.

Most intriguingly, the researchers found a link between lack of sleep and drug use. When a teen’s friend slept less than 7 hours, her chances of using drugs went up by 19%. And that means that as sleep deprivation spreads throughout a friend network, drug use spreads as well. Exactly why this happens is still unclear, Fowler said.

The next step, Fowler told audience members, is to try to confirm some of his team’s observations using Facebook. That will give the researchers access to the teens themselves—and it could allow them to start testing interventions. For example, Fowler said his group could see if teens who catch up on their sleep by napping during the day start smoking less pot.