A study of more than 5,000 youngsters in Switzerland has found those who smoked cannabis do as well or better in some areas as those who don't, researchers said on Monday.
But the same was not true for those who used both tobacco and cannabis, 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 cannabis and tobacco functioned better overall, the authors said.
In fact, those who used only cannabis were "more socially driven ... significantly more likely to practice sports and they have a better relationship with their peers than abstainers," it said.
"Moreover, even though they are more likely to skip class, they have the same level of good grades; and although they have a worse relationship with their parents, they are not more likely to be depressed than abstainers," it added.
It did not explain the reasons behind the apparent effect.
The study, published in the November issue of the Archives of Pediatrics & Adolescent Medicine, was based on a 2002 survey of 5,263 Swiss students age 16 to 20, of whom 455 smoked cannabis only, 1,703 who used both cannabis and tobacco and 3,105 who abstained from both.
The report said that while cannabis use has declined among U.S. adolescents, it has increased in recent years among the same age group in Switzerland and other European countries.
Source: Swiss study has some surprises on marijuana use