Pot smokers might not turn into dopes after all

Revisiting data casts doubts on link between heavy cannabis use and declining IQ
Monday, January 14, 2013

rolling-joint2Cannabis rots your brain — or does it? Last year, a paper published in Proceedings of the National Academy of Sciences (PNAS) suggested that people who used cannabis heavily as teenagers saw their IQs fall by middle age. But a study published today — also in PNAS — says that factors unrelated to cannabis use are to blame for the effect. Nature explores the competing claims. (See also: New Research Questions Marijuana’s Impact in Lowering IQ)