A striking survey from Europe:
A study of more than 5,000 youngsters in Switzerland has found those who smoked marijuana do as well or better in some areas as those who don't, researchers said Monday.
But the same was not true for those who used both tobacco and marijuana, who tended to be heavier users of the drug, said the report from Dr. J.C. Suris and colleagues at the University of Lausanne.
The study did not confirm the hypothesis that those who abstained from marijuana and tobacco functioned better overall, the authors said.
In fact, those who used only marijuana were "more socially driven ... significantly more likely to practice sports and they have a better relationship with their peers" than abstainers, it said.
I should add I don't support the legal use of marijuana by teenagers. I'd be happy to keep it illegal for the under-age, as with cigarettes. But it does not surprise me that moderate use of the drug has no correlation with personal, social or academic failure.