Marijuana is a tricky drug, alternately demonized as a gateway drug and lionized for its medical promise. And while the juries remain out on both sides of the coin, one thing is clear: its use is on the rise. According to the US Department of Human Health and Services, the number of people in the United States who admit to smoking pot in the last month climbed from 14.4 million in 2007 to over 18 million in 2011.
This increase may in part be due to the lack of strong evidence supporting the suspected risks of cannabis use. Indeed, though marijuana smoke carries carcinogens and tar just as tobacco smoke does, definitive data linking marijuana to lung damage is lacking. And a recent long-term study that seemed to conclusively link chronic marijuana initiated in adolescence to a lowered IQ in New Zealanders was quickly challenged by a counter-analysis that pointed to socioeconomic status as a confounding factor. According to survey data from the Centers for Disease Control and Prevention, cannabis use increases in teenagers as marijuana’s perceived risks decline, and researchers—and undoubtedly some parents—are anxious to get to the bottom of the matter.
Resourse: The Scientist