TIRED TEENS MORE LIKELY TO USE MARIJUANA

Behaviours Spread Through Social Networks, Researchers
Find

Sleep-deprived teens are more likely to smoke marijuana, a new study
shows, and their friends -- and their friends' friends' friends' --
are more likely to be missing sleep and using drugs, too.

The study is the latest from researchers at the University of
California at San Diego to find that behaviours like smoking, obesity
and happiness spread through people's social networks, but it's the
first to show that the spread of one behaviour influences others, too.

"It really means that we're all connected," says Sara Mednick, an
assistant psychiatry professor. "All of our behaviours lead to other
behaviours and when we think about treating one issue in isolation,
we're missing the point that treating an entire milieu is probably
more effective."

The study included 8,349 teens from the National Longitudinal Study of
Adolescent Health, which tracked students over eight years and created
a snapshot of their social circles by asking each participant to name
up to five male and female friends who were also in the study.

Within the social networks, the researchers found large clusters of
sleep-deprived teens and groups of friends who had all tried marijuana.

A teen was 11 per cent more likely to sleep seven or fewer hours a
night if they had a friend who did so, they found.

And if a friend started smoking pot, that more than doubled the
chances that a teen would do the same.

This influence persists up to four degrees of separation, with a
teen's friends' friends' friends wielding some influence on their
sleep and drug habits.

The study is the first to demonstrate that sleep habits spread through
social networks, Mednick says, and while conventional wisdom holds
that sleep deprivation is a common result of drug use, they uncovered
the opposite pattern.

"It goes from poor sleep to drugs," she says, adding that teens who
are sleep deprived tend to have behavioural problems, quicker
reactions and fewer inhibitions. "Maybe those are the kids who are
more likely to do drugs because they'll probably make these poor
decisions, and if they're really tired, they may just say, 'I'll use
something to make me feel better'."

Negative health behaviours are more influential than positive ones,
the researchers found, and the social butterflies at the centre of
these social networks are more likely to smoke marijuana and miss out
on hours of sleep.

"The kid who is the most popular is the one who actually suffers the
most in this situation," Mednick says.

However, that also suggests a possible remedy, she says, in
"strategically" targeting the most influential people with anti-drug
or pro-health messages in order to have the greatest impact on the
group as a whole.

To ensure these effects were due to the influence of one teen on
another and not an outside factor that affected them both -- a noisy
neighbourhood where sleep is difficult, for instance, or a drug dealer
living nearby -- the researchers examined different types of
friendships in the networks.