Columbia researchers are crowing about a new drug use study. University of Missouri Communication professor Mike Stephenson says the goal was to use MTV-style ads to reach thrill-seeking teenagers who’re more likely to use pot. He and a group of researchers from the University of Kentucky produced a series of novel, fast-paced ads that he says reduced pot use among the high-sensation set in a short period of time. Precise results will be released this week in the American Journal of Public Health.