The first part of the report, "Necessary Preconditions," focuses on several factors that are necessary for substance abuse and addiction to occur, including an examination of the biological research regarding the phenomenon of addiction to a variety of substances. In addition to a discussion of biology and pharmacology, this section considers drug availability and transitions to abuse and addiction. The second part, "Individual Factors," describes individual risk and protective factors that contribute to the abuse of and addiction to alcohol and drugs. Demographic, economic, and psychosocial/behavioral factors are considered. The third part, "Community Contexts," examines how risk and protective factors play out in subcultures and in major activity settings (home, school, workplace, and recreation) and assesses the effectiveness of various substance abuse prevention initiatives. The fourth section, "Policy Options," addresses a range of legislative issues and options for Congress that derive from an understanding of the factors that lead to substance abuse and addiction. The policy issues discussed relate to the broad categories of Federal focus and prevention program structure, research needs, community activity settings, and availability. A number of policy questions and options for congressional action emerge from these four areas of concern. 489 references and a subject index