Comparison of young adult and adolescent rates of outcomes with evidence of attenuation. Graphs compare rates for (a) alcohol abuse/dependence, (b) marijuana abuse/dependence, and (c) illicit drug abuse/dependence. Alcohol abuse/dependence increased for on-time/late maturers (odds ratio=6.3, 95%CI 1.8, 22.3; p=.005) did not significantly change for early maturers (odds ratio=0.7, 95%CI 0.1, 4.6; p=.67). Marijuana abuse/dependence did not differ significantly from adolescence to young adulthood for either early maturers (odds ratio=0.4, 95%CI 0.1, 2.6; p=.34) or on-time/late maturers (odds ratio=1.4, 95%CI 0.6, 3.3; p=.39). Illicit drug abuse/dependence decreases in early maturers (odds ratio=0.2, 95%CI 0.0, 0.7; p=.01) and increased in on-time/late maturers (odds ratio=4.6, 95%CI 1.5, 13.7; p=.007). * Indicates significant group difference.