The survey, conducted by the National Institute on Drug Abuse, covers the U.S. population aged 12 and over living in households. This year, for the first time, the survey has been expanded to include college students in dormitories, homeless people in shelters, civilians in military installations, and special expanded samples of six major metropolitan areas. The survey findings are based on personal interviews and self-administered questionnaires from 32,594 respondents. The DAWN data indicate drug-related episodes and drug "mentions" in a nationally representative sample of U.S. hospital emergency rooms (ER's). The National Household Survey on Drug Abuse indicates that for most drugs, including alcohol and tobacco, and most populations, use has continued to decrease over the past year; however, the use of cocaine and heroin for certain groups have apparently reversed this trend and have increased toward the level of previous years. Cocaine use in the general population increased by nearly 20 percent from 1990. The DAWN data reinforce the survey data as they show a 31-percent increase in cocaine-related ER mentions between the fourth quarter of 1990 and the second quarter of 1991. Marijuana remains the most commonly used illicit drug in the United States. 5 tables and 2 figures