Table 1.

Demographic characteristics and substance use history of participants. Asterisks indicate a significant difference between the groups (Independent Samples t-test, p=0.001)

	Group Alc0	Group Alc30
N	11	14
Age (mean ± SD)	25.7 ± 2.7	26.4 ± 3.8
Body Mass Index (kg/m2)*	23.0 ± 1.6	25.6 ± 1.8
Race (N / %):
European-American	7 / 64	7 / 50
African-American	3 / 27	4 / 29
Asian-American	0 / 0	1 / 7
Other	1 / 9	2 / 14
Current Drug Use (mean ± SD)
Alcoholic drinks/wk	4.6 ± 4.6	4.4 ± 3.3
Caffeine cups/wk	6.8 ± 4.2	5.4 ± 5.0
Cigarettes/wk	0.0 ± 0.0	0.1 ± 0.3§
Marijuana times/month	0.2 ± 0.4	0.9 ± 1.5
Lifetime Drug Use (N / % ever used)
Stimulants	2 / 18	4 / 29
Sedatives	1 / 9	1 / 7
Hallucinogens	3 / 27	4 / 29
Opiates	1 / 9	4 / 29
Marijuana	8 / 73	12 / 86
Inhalants	2 / 18	2 / 14
Full Time Student (N / %)	2 / 18	2 / 14

^§One participant smoked one cigarette per week in the Alc30 group.