WaPo: Potent pot, vulnerable teens trigger concerns in first states to legalize marijuana. “‘The brain is abnormally vulnerable during adolescence,’ said Staci Gruber, an associate professor of psychiatry at Harvard Medical School who studies how marijuana affects the brain. ‘Policy seems to have outpaced science, and in the best of all possible worlds, science would allow us to set policy.'” (Policy driven by science. What a concept.)

+ “The risk that marijuana use poses to adolescents today is far greater than it was 20 or 30 years ago, because the marijuana grown now is much more potent. In the early 1990s, the average THC content of confiscated marijuana was roughly 3.7 percent. By contrast, a recent analysis of marijuana for sale in Colorado’s authorized dispensaries showed an average THC content of 18.7 percent.” NYT: Marijuana Damages Young Brains.