Table 2. Trends in Selected Drug Use Indicators, 1979–2000¹ (Estimated Number and Percent Prevalence)

Year	Current use of any illicit drug2	Current cocaine use2	Occasional (less than monthly) cocaine use	Current marijuana use2	Lifetime heroin use	Any adolescent3 illicit drug use2	Lifetime adolescent3 inhalant use4
Users (thousands)
1979	25,400	4,700	—	23,800	2,300	4,100	—
1982	—	4,500	—	21,500	1,800	2,800	—
1985	23,300	5,700	7,100	18,600	1,800	3,200	—
1988	15,000	3,100	5,100	12,400	1,700	1,900	—
1990	13,500	1,700	3,700	10,900	1,500	1,600	—
1991	13,400	2,000	3,800	10,400	2,400	1,400	—
1992	12,000	1,400	3,000	9,700	1,700	1,300	—
1993	12,300	1,400	2,700	9,600	2,100	1,400	—
1994	12,600	1,400	2,400	10,100	2,100	1,800	1,500
1995	12,800	1,500	2,500	9,800	2,500	2,400	1,600
1996	13,000	1,700	2,600	10,100	2,400	2,000	1,300
1997	13,900	1,500	2,600	11,100	2,000	2,600	1,600
1998	13,600	1,800	2,400	11,000	2,400	2,300	1,400
1999-CAI	13,829	1,552	1,926	10,458	3,054	2,265	2,118
2000-CAI	14,027	1,213	1,732	10,714	2,779	2,264	2,079
Rate of use (%)
1979	14.1	2.6	—	13.2	1.3	16.3	—
1982	—	2.4	—	11.5	1.0	—	—
1985	12.1	3.0	3.7	9.7	0.9	13.2	—
1988	7.7	1.6	2.6	6.2	0.9	8.1	—
1990	6.7	0.9	1.8	5.4	0.8	7.1	—
1991	6.6	1.0	1.9	5.1	1.2	5.8	—
1992	5.8	0.7	1.5	4.7	0.8	5.3	—
1993	5.9	0.7	1.3	4.6	1.0	5.7	—
1994	6.0	0.7	1.2	4.8	1.0	8.2	7.0
1995	6.1	0.7	1.2	4.7	1.2	10.9	7.4
1996	6.1	0.8	1.2	4.7	1.1	9.0	5.9
1997	6.4	0.7	1.2	5.1	0.9	11.4	7.2
1998	6.2	0.8	1.1	5.0	1.1	9.9	6.1
1999-PAPI	7.0	0.8	—	5.4	—	9.0	—
1999-CAI	6.3	0.7	0.9	4.7	1.4	9.8	9.1
2000-CAI	6.3	0.5	0.8	4.8	1.2	9.7	8.9

— Data not available.

¹ In 1999, the survey methodology changed from a paper-and-pencil interview (PAPI) to a computer-assisted interview (CAI). A PAPI supplement conducted in 1999 provides estimates that are comparable to previous years. Estimates based on the new CAI methodology are not directly comparable to previous years.
² Data for past-month (current) use.
³ Ages 12–17 years.
⁴ Prior to a 1994 questionnaire change; data did not allow separate reporting for this age group.

Note: "Any illicit drug use" includes use of marijuana, cocaine, hallucinogens, inhalants (except in 1982), heroin, or nonmedical use of sedatives, tranquilizers, stimulants, or analgesics. The exclusion of inhalants in 1982 is believed to have resulted in underestimates of any illicit use for that year, especially for adolescents.

Sources: National Institute on Drug Abuse (1979–1991), and Substance Abuse and Mental Health Services Administration (1992–2000), National Household Survey on Drug Abuse.