Marijuana use among American adolescents has been increasing gradually over
the past two years (three years among 12th graders) following years of declining use, according to the latest Monitoring the Future study, which has been tracking drug use among U.S. teens since 1975. “So far, we have not seen any dramatic rise in marijuana use, but the upward trending of the past two or three years stands in stark contrast to the steady decline that preceded it for nearly a decade,’’ said University of Michigan researcher Lloyd Johnston, the study’s principal investigator. “Not only is use rising, but a key belief about the degree of risk associated with marijuana use has been in decline among young people even longer, and the degree to which teens disapprove of use of the drug has recently begun to decline. Changes in these beliefs and attitudes are often very influential in driving changes in use.”