Available indicators on drug use tell a confusing story. Although surveys show that drug use has declined in the general population since 1980, direct measures of use, such as the number of drug-related deaths, have been increasing steadily. The extent of the nation's drug problems cannot be measured by estimating the number of persons using illicit drugs. General surveys mask a considerable change in drug-use patterns. Analysis and reconciliation of various indicators, along with a solid understanding of patterns of use, can reveal differences among segments of the population and can help to distinguish among, for example, the teenage marijuana user, the occasional user of cocaine, and the crack cocaine- or heroin-dependent person for whom drug use is a career rather than an event. It can also help policymakers and community leaders tailor drug prevention and reduction programs to particular audiences — high school students, criminal offenders, or particular age or racial groups.