This volume is the second in an annual series surveying the lifestyles and values of youth. Presented here are detailed statistics on the prevalence of drug use among American high school seniors in 1978 and on trends in those figures since 1975. Research involved annual data collection in approximately 125 public and private high schools across the U.S. Explored are students' attitudes about drug use, exposure to drug use, and perceptions about the availability of drugs. New subjects covered this year include the intensity and duration of the highs usually experienced with the various drugs and the cross-cohort comparisons of the rate of initiation into drug use. Also new this year are two figures in each drug chapter that deal with trends in drug use at earlier grade levels. Finally, two new chapters have been added that deal with certain relevant aspects of the social milieu in which American teenagers find themselves. (Author)