Four Percent of the world population smokes cannabis

Canada.com reports that 'The Lancet' has an article stating that 4% of the world smokes pot.
The article is a somewhat interesting read.

http://www.canada.com/Technology/Four%20percent%20adults%20worldwide%20using%20cannabis%20Lancet/2110648/story.html?id=2110648

Around nine percent of people who ever use cannabis become dependent on it, says the paper. By comparison, the risk of addiction for nicotine is 32 percent, 23 percent for heroin, 17 percent for cocaine and 15 percent for alcohol.

The article also rehashes the old carcinogens in cannabis story, plus some other arguable points. However, on the whole, the article is well balanced.

"A high THC content can increase anxiety, depression and psychotic symptoms in naive (read-new) users, while increasing the risk of dependence and psychotic symptoms if regular users do not titrate [measure out] their dose."

I think Canada.com may be sitting on the fence in respect to this article.