The prevalence of drug use in the United States

The four major sources of data on the prevalence of use of illicit drugs-the National Household Survey on Drug Abuse, the High School Senior Survey (Monitoring the Future), the Drug Abuse Warning Network, and the Drug Use Forecasting System-tell us much that we want to know about drug abuse patterns and trends but not enough. The first two are self-report surveys of representative national samples, but. they undercount (or exclude) high-risk groups like the homeless and active offenders. There is also doubt about the external validity of their findings. The last two have design characteristics that prevent generalization to the entire population. Recent changes in the surveys and use of synthetic techniques is improving capacity to make reliable national estimates of drug use prevalence, but current estimates differ by orders of magnitude.