Table 3.

Percentage of engagement in each of 16 illicit substances by age cohort and study wave

	Age 12			Age 13			Age 14			Age 15			Age 16			Age 17
	W1	W2	W3	W1	W2	W3	W1	W2	W3	W1	W2	W3	W1	W2	W3	W1	W2	W3
Prescription drug misuse
Tranquilizers	0.2	0.3	0.5	0	1.5	1.4	1.6	1.3	2.3	2.7	3.1	3.9	4.0	2.8	4.3	5.6	4.8	4.0
Barbiturates	0.8	0	0	0.5	0	1.4	1.4	1.8	2.0	2.8	1.1	2.3	2.3	1.3	0	3.4	1.8	2.7
Amphetamines	0	0.3	0.5	0.2	0.5	2.4	1.7	1.3	2.0	4.2	3.1	2.6	4.2	2.8	4.6	5.1	5.0	5.8
Pain medication	0.4	1.5	1.4	1	0.7	3.8	3.3	1.6	2.6	3.6	3.3	6.5	4.3	5.6	5.6	9.6	5.3	4.5
Steroids	0	0	0.5	0.2	0	0.7	0.2	0	0	0.5	0.4	0.7	0.3	0	0	0.2	0.3	0.4
Common street drugs
Marijuana	0.8	3.6	8.1	3.7	5.7	12.9	10.1	9.8	16	16.7	17.6	24.4	24.3	22.6	27.5	33.2	24.4	27.7
Crack/cocaine	0	0.3	0.5	0.2	0.2	1.0	0.6	0.2	0	1.9	0.7	2.6	2.5	3.0	2.3	5.4	4.3	4.9
Angel dust/PCP	0	0	0.5	0	0.2	0.3	0.3	0	0	0.8	0	0.7	0.3	0	0	0.8	0	0
Methadone/heroin	0	0	0	0.2	0	0.7	0.3	0.2	0.3	0.5	0.2	1.0	0.5	0.4	0.7	0.8	0.5	0.4
Inhalants	0.2	0.9	0.5	1.2	0.2	0.3	1.6	0.7	0.3	3.0	0.7	1.3	1.5	0.4	1.3	2.7	1.0	1.3
Club drugs
Ecstasy	0.2	0.6	0.9	0	0.5	1.4	1.1	1.6	1.6	1.7	1.5	4.2	1.9	2.6	3.0	3.5	2.8	5.4
GHB	0	0.3	0	0	0	0	0.5	0.2	0.3	0.2	0.2	0.3	0	0.2	0.3	0.6	0.3	0
Ketamine	0	0	0	0	0	0	0.3	0	0	0.6	0	0.7	0.3	0.2	0.7	0.3	0.5	0
Rohypnol	0	0	0	0	0	0	0.2	0	0	0.2	0	0	0.2	0.2	0	0.2	0.3	0
Metamphetamine	0	0.3	0.5	0	0.2	0.7	0.8	0.4	0.3	1.9	0.7	0.7	1.2	0.9	1.0	2.7	1.0	1.8
Hallucinogens	0	0.6	0.9	0.2	0.2	2.1	1.3	0.9	1.6	2.7	1.5	3.3	2.9	3.0	4.6	5.1	4.3	7.1