Introduction

The 1997 NHSDA provides estimates of the prevalence of use of 17 types of licit and illicit substances. These measures reflect drug use by the U.S. household population aged 12 or older at a single point in time. Because similar data have been collected in previous administrations of the NHSDA since 1972, it is possible to examine how prevalence rates for specific types of drug use have changed between prior years of the survey and the most recent year, 1997. Comparing the estimates produced by the 1997 NHSDA with those produced in previous years is helpful for interpreting the current magnitude of the drug use levels in the United States within an historical context, and for identifying noteworthy trends based on the more recent years of data.

For the entire household population, the estimated rates of use of specific illicit drugs, alcohol, and tobacco did not change appreciably from 1996 to 1997 and, in general, were relatively stable from 1991 to 1997. Rates of substance use were generally much higher in the late 1970s and early 1980s than they were in 1997. Unfortunately, however, illicit drug use among youths aged 12 to 17 increased in 1997, extending a general upward trend for this age group that began about 1992. Findings from the 1996 survey (OAS, 1998a) had suggested that this trend may have reversed itself, as evidenced by a statistically significant decline in any past month illicit drug use among youths aged 12 to 17 from 10.9% in 1995 to 9.0% in 1996. In 1997, however, this rate jumped to 11.4%, the highest it had been since 1985. This increase was driven in large part by the significantly higher rate of past month use of marijuana in 1997 compared with 1996. Although rates of alcohol use, including heavy use, and cigarette use among youths also tended to be higher in 1997 than in 1996, the increases were less dramatic and not statistically significant.

This chapter first presents the lifetime, past year, and past month use of the 17 types of substances, as measured by the 1997 NHSDA. These 1997 results are then compared with the rates of use from 1979 through 1996.5 Next, the prevalences of lifetime, past year, and past month use of any illicit drug, marijuana, cocaine, alcohol, and cigarettes are presented for NHSDAs conducted from 1979 through 1997 for each of four standard age groups. Finally, the lifetime, past year, and past month rates of use in 1996 and in 1997 are presented for all 17 of the types of substances for each of the four standard age groups.

5 Estimates from all years of the NHSDA since 1979 are included in these tables with the exception of 1990, which was excluded to allow adequate space for the addition of the 1997 data.