Mixture model for heavy drinking at Waves 1–6, weighted by estimated class probabilities. N = 377. Heavy drinking was scored as 0 = didn’t drink 5 or more drinks at a single sitting in the past 30 days, 2 = once during the past 30 days, 3 = two to three times during the past 30 days, 4 = once or twice a week, 5 = three to four times a week, 6 = five to six times a week, and 7 = nearly every day. Later Ons. = later onset; Dev Limited = developmentally limited.