Researchers who studied teenagers' social networks concluded that those who were sleep-deprived were more likely to use marijuana, and that the pattern tended to be repeated among clusters of their friends, the CanWest News Service reported March 19.
The University of California at San Diego study of 8,249 teens found that “all of our behaviors lead to other behaviors and when we think about treating one issue in isolation, we're missing the point that treating an entire milieu is probably more effective,” said study author Sara Mednick.
For example, a teen was 11 percent more likely to get seven or fewer hours of sleep nightly if they had a friend who did so, and having a friend who smoked marijuana more than doubled teens' odds of doing so themselves. Such influences persisted even through four degrees of separation.
Researchers also found that negative health behaviors carried more influence that positive behaviors among social networks.
The findings were published in the journal PLoS One.