This two-volume monograph reports the results of the 24th national survey of drug use and related attitudes and beliefs among American high school seniors, the nineteenth such survey of American college students, and the eighth such survey of eighth- and tenth-grade students. The major purpose of this publication is to develop an accurate picture of current drug use and trends. Given the illicit and illegal nature of most of the phenomena under study and the absence of prevalence data, substantial misconceptions can develop and resources may be misallocated. Throughout this report, the focus in on drug use at the higher frequency levels rather than simply on who has used various drugs. A summary of the findings on trends includes: over more than a decade--from the late 1970s to the early 1990s--these were very appreciable declines in use of a number of illicit drugs among twelfth-grade students, and even larger declines in their use among American college students and young adults. These substantial improvements--which seem largely explainable in terms of changes in attitudes, beliefs about the risks of drug use, and peer norms against drug use--have some extremely important policy implications. One of these is that these various substance-using behaviors among American young people are malleable--they can be changed. Secondly, the demand-side factors appear to have been pivotal in bringing about these changes. the availability of marijuana, as reported by high school seniors, has held fairly steady throughout the life of the study. Improvements should not be taken for granted; relapse is always possible. In 1992, eighth graders exhibited a significant increase in annual use of marijuana, cocaine, LSD, and hallucinogens other than LSD, as well as an increase in inhalant use. In 1993, increases occurred in a number of "gateway drugs"--marijuana, cigarettes, and inhalants. The drug problem requires an ongoing, dynamic response from our society--one that takes into account the continuing generational replacement of our children and the generational forgetting of the dangers of drugs which can occur with that replacement. Contains 5 appendixes, 128 tables, and 105 figures.) (JDM)