Blacks have lower rates of substance use and abuse than whites in early adolescence and young adulthood but similar or higher rates by middle adulthood, which could be due to Blacks being less likely to age (i.e., mature) out of deviance than Whites by transitioning into high-quality conventional social roles. Using the National Comorbidity Survey (1990-1992), this study finds that work, economic conditions, and family roles explain the race-by-age crossover for drug abuse and explain most of this relationship for alcohol use and abuse. There is no race-by-age crossover for drug use. Thus, even though Blacks have lower substance use and abuse than Whites at younger ages, this advantage is eliminated and even reversed due to the disadvantages Blacks face over the life course. (Published Abstract) Tables and references