Daily Pot Use Surpasses Cigarettes among High School Seniors

The Centers for Disease Control have spent $50 million a year to persuade Americana teenagers to stop smoking. It appears to be money well spent. Using federal money, the University of Michigan has monitored smoking by American middle- and high-school students for the past 41 years. The latest results show some of the lowest levels in history. Nora Volkow, director of the National Institute on Drug Abuse, has more on the study's findings.