As expected, prevalence rates for drug use at pretest, when the youths were 11 years old, were low: 15% for any alcohol use, 1.2% for binge drinking, and 0.0% for marijuana use. Lifetime prevalence rates increased over time; at the long-term follow-up, when the youths were 14 years old, lifetime rates were 39.2% for alcohol use, 4.6% for binge drinking, and 4.3% for marijuana use. Likewise, average past-month substance use was low at pretest (M = .07, SD = .42) but increased across waves to long-term follow-up (M = .17, SD = .73). These rates for African American youths are consistent with data from other studies (Johnston, O’Malley, Bachman, & Schulenberg, 2007).
