Across racial/ethnic groups, there were little yearly variations in the prevalence of cannabis abuse and dependence during 2005–2013. Regardless of year, cannabis dependence was more common than abuse; blacks, native-Americans, and mixed-race adults tended to show a pattern of a higher prevalence of cannabis dependence than whites. In 2013, the CUD prevalence was higher among blacks (2.40%, 95% CI=1.80–3.21%), native-Americans (4.15%, 95% CI=2.57–6.63%), and mixed-race adults (3.50%, 95% CI=2.08–5.83%) than whites (1.30%, 95% CI=1.11–1.52%) (Figure 1a).
