This report contains detailed statistics on the prevalence of drug use among American high school seniors in l983, and on trends in those figures since l975. The introduction provides an overview of the study design and purposes; defines the larger population represented by the survey samples; and discusses sampling procedures, questionnaires and administration methods, the representativeness of the sample, and the validity of the self-report measures of drug use. Section II provides an overview of important results. Section III, Prevalence of Drug Use and Recent Trends, is divided into 12 chapters. Chapter 1 provides a compilation across drugs of the key results contained in chapters 2 through 12 which deal with actual use of various drugs: marijuana/hashish, inhalants, hallucinogens, cocaine, heroin, opiates other than heroin, stimulants, sedatives, tranquilizers, alcohol, and cigarettes. Extensive figures and data tables are included in each chapter. A standard set of tables with comparable table numbers from chapter to chapter are used whenever possible. The key points from data tables are presented in a brief, structured format at the beginning of each chapter. Chapters have been organized and formatted to facilitate use of this report as a reference work. Section IV examines attitudes and beliefs about drugs and the social milieu. Section V presents other findings from the survey. A brief guide for interpreting data tables is appended and all measures discussed in the report are either given or operationally defined in the appendices. (Author/NRB)