For 2006, just under half of American secondary school students had tried an illicit drug by the time they neared high school graduation. The use of any illicit drug in the 12 months preceding the survey had declined by more than a third among eighth graders since the peak for that grade in 1996. It was down by a quarter among 10th graders, but by only approximately 14 percent among 12th graders. Tenth and 12th graders reached their recent peaks in drug use in 1997. In the 1-year interval from 2005 to 2006, no grade level had a statistically significant decline in any prevalence period in the index; however, gradual declines did continue in all grades, with the 12th grade showing the largest decline (1.9 percentage points to 36.5 percent). A number of specific drug classes show continuing declines from 2005 to 2006 in at least one grade. These included marijuana, any illicit drug other than marijuana, hallucinogens other than LSD, amphetamines, methamphetamine, alcohol, and cigarettes. Among the many drugs that showed virtually no change in 2006 at any grade level were LSD, powder cocaine, crystal methamphetamine, heroin, narcotics other than heroin, tranquilizers, steroids, and three so-called "club drugs" (ketamine, rohypnol, and GHB). Only four drugs showed any sign of increased use: ecstasy, oxycontin, vicodin, and inhalants. In each case, the increases were modest and confined to one or two grades. Extensive figures and tables