This report presents the first results from the 1994 National Household Survey on Drug Abuse, showing trends since the 1970s and providing information to identify population groups for which prevention and treatment interventions could have greatest impact. These preliminary results indicate that the number of illicit drug users has not changed since 1992, a leveling that follows more than a decade of decline from the 1979 high. No change has been found in the number of weekly cocaine users, although the number of occasional users has declined. The rate of past-month alcohol use declined from 1979 to 1992, but since then the rate has increased slightly. In an average month in 1994, 6% of Americans aged 12 years and older used illicit drugs, with marijuana being the most commonly used, and 6.2% of the population had 5 or more drinks per occasion on 5 or more occasions. Adolescent marijuana use, declining from 1979 to 1992, has nearly doubled between 1992 and 1994. Heavy drinking remains most prevalent for those aged 18 to 21 and 22 to 25. These findings from a nationally representative sample point out the need for increased education and prevention efforts. Five appendixes present supplemental information about data collection and survey methodology, including 2 tables in Appendix 2 and 40 detailed tables in Appendix 5. (Contains 13 figures and 45 references.) (SLD)