Thinking Clearly

Pot Smokers Might Not Turn into Dopes after All 

By Arran Frood and Nature magazine at SCIENTIFIC AMERICAN 

  Cannabis 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.