Everybody knows that if two things are associated, one must cause the other. Clouds lead to rain, eating dinner makes it get dark outside... oh, hang on.
Anyway, the National Center on Addiction and Substance Abuse (CASA) at Columbia University is no doubt absolutely right when it says that Facebook use makes teens take drugs.
After all, they've found that teens aged between 12 and 17 who spend any time on social networking sites like Facebook and Myspace are likelier to smoke, drink or use drugs.
In a typical day, its survey found, 70 percent of 12- to 17-year olds spend time social networking. And those that do are twice as likely to use marijuana, at 13 percent compared to seven percent for those who don't use social networking at all.
They're also five times likelier to use tobacco, at ten percent, and nearly three times likelier to use alcohol, at 26 percent compared with nine percent.
And kids who said they'd seen people passed out on Facebook said they were four times likelier to be able to get marijuana in a day or less than those that hadn't seen such pictures.
"Unfortunately, most parents do not appreciate the risks of their teen social networking," warns CASA founder and chairman Joseph A Califano.
Unfortunately, the team doesn't seem to have examined drug use amongst teens who have no social contact at all, virtual or otherwise. A pity: they might have discovered that kids in a coma, say, are less likely to take drugs than those that play football every week.
Just think of the headline they could have given their press release then.