WASHINGTON (AP) _ Illicit drug use by teens continued to gradually decline overall this year, but teen use of prescription painkillers remains popular, according to a University of Michigan study released Tuesday at the White House.
Overall decreases were seen among 8th, 10th and 12th graders nationwide, according to the study by the university's Institute for Social Research. President Bush was scheduled to comment on the study's findings later Tuesday.
``The cumulative declines since recent peak levels of drug involvement in the mid-1990s are quite substantial especially among the youngest students,'' said Lloyd Johnston, the principal investigator of the study, which surveyed 50,000 teens.
The drugs most responsible for this year's decline in illicit drug use are marijuana and various stimulants, including amphetamines, methamphetamine and crystal methamphetamine.
The proportion of 8th graders reporting use of an illicit drug at least once in the 12 months prior to the survey was 24 percent in 1996. It now has fallen to 13 percent _ a drop of nearly half.
Among 10th graders, the rates dropped from 39 percent to 28 percent between 1997 and 2007. Twelfth graders saw a decline from a peak of 42 percent in 1997 to 36 percent this year.
While use of most illicit drugs have shown declines in the past decade or so, most prescription psychotherapeutic drugs did not. A number of them showed steady increases in use outside of their legitimate medical purpose. These include sedatives, tranquilizers and narcotic drugs other than heroin.