Table 1.

Demographic characteristics of sample at baseline

Variable	M (range) or frequency %
Age, in years	12.0 (11.0–13.6)
Male gender	51.6%
Race/ethnicity
Non-Hispanic White	39.5%
Black	24.9%
Asian/Pacific Islander	24.1%
Hispanic	10.1%
Native American	1.4%
Household income
Low income, <$34,999	33.4%
Mid income, $35,000–$74,999	35.5%
High income, ≥$75,000	31.1%
Single-parent household	27.3%
Lifetime history of any substance use disorder among biological parentsa	42.0%

^aBased on the Family History Screen (Weissman et al., 2000) collected at the eighth-grade interview (n = 457).