Professor Lloyd Johnston of the University of Michigan in his survey in 50,000 teen students found that there was a decrease in smoking in these students but alarmingly found an increase in drug abuse of various painkillers . The researchers found that almost 50% of students in the 12th grade are abusing drugs. The increase in use of painkillers may be linked to increased stress these students are exposed or due to their ignorance regarding the ill effects of using prolonged painkillers. The painkillers the teen students mostly take are Oxycontin, Vicodin or Marijuana. The researchers feel that teen students should be well informed about the ill and side effects involved in drug abusing as study shows that more and more teens are popping up pain killers.