Overall, our results provide limited evidence for a cross-over in racial-ethnic differences in substance use in the general population through early adulthood. However, there is convergence in almost all cigarette and marijuana use measures at this developmental period. Results for cigarettes and marijuana use suggest that race/ethnic disparities in substance-related consequences that often occur later than young adulthood may arise in part due to race/ethnicity differences in use of these substance that vary across lifecourse stages. These results were apparent in unadjusted models and persisted after rigorous control for socio-economic differences.
