The authors explain that African-Americans are at higher risk for drug-related health and socio-economic problems than are European Americans. Curiously, however, drug and alcohol abuse among adolescent African-Americans is lower than among adolescent European Americans. Furthermore, the relationship between risk factors and drug and alcohol abuse are weaker among African-American adolescents than among European American adolescents. As such, the authors explore the possibility that the risk factors for drug and alcohol dependence develop later in the life course for African-Americans. To test this hypothesis, the authors followed a cohort of adolescents from 1990 through 1998, measuring risk factors during early adolescents as predictors of DSM-IV alcohol and marijuana dependence. The findings revealed that school factors and drug use among peers and family members were the most influential risk factors for drug abuse among both the African-American cohort and the European American cohort. Furthermore, while levels of drug use were lower among the African-American adolescents, findings showed that their exposure to risks was higher than other groups, impacting the long-term consequences of drug and alcohol abuse. In conclusion, the authors point out that efforts to curb drug and alcohol use among African-Americans hinge on the timing of the prevention efforts. Tables, references