This document is the first volume of a two-volume report presenting the results of the 18th national survey of drug use and related attitudes among American high school seniors and the 13th national survey of American college students. Volume I contains the results from the secondary school samples of 8th, 10th, and 12th graders. The volume contains 10 chapters. Chapter 1 provides an introduction to the report. Chapter 2 contains an overview of key findings, looking at trends in illicit drug use, alcohol use, and cigarette smoking, and the drug use of 8th graders. It is noted that, over the last decade, there have been appreciable declines in the use of a number of illicit drugs among high school seniors. Chapter 3 describes the study design and procedures; chapter 4 considers the prevalence of drug use among 8th, 10th, and 12th graders; chapter 5 examines trends in drug use among secondary school students; and chapter 6 focuses on drug use at earlier grade levels. Chapter 7 concentrates on the degree and duration of drug highs. Chapter 8 explores attitudes and beliefs about drugs and chapter 9 considers the social milieu. Other findings from the study, including findings on the use of nonprescription stimulants and the use of marijuana on a daily basis are presented in chapter 10. Prevalence and trend estimates adjusted for absentees and dropouts are appended. Thirty-four tables and 36 figures are included. (NB)