Figure 1.

Triple trajectories of alcohol use, cigarette use, and cannabis use from mid adolescence to emerging adulthood (mean age 14-24).

Note. Response options for alcohol use: none (0), less than once a week (1), once a week to several times a week (2), 1 or 2 drinks everyday (3), and three or more drinks every day (4); cigarette use: none (0), a few cigarettes or less a week (1), 1-5 cigarettes a day (2), about half a pack a day (3), about 1 pack a day (4), about 1 and half packs a day (5), and more than 1 and half packs a day (6); and cannabis use: never (0), a few times a year or less (1), about once a month (2), several times a month (3), and once a week or more (4).