The role of cigarettes in the initiation and progression of early substance use.

This study examined progression in substance use from initiation to eventual regular use and provided information on a number of levels. Cigarette use was shown to fall on a cumulative (Guttman) scale of use with other drugs (e.g., marijuana, beer, liquor, stimulants or depressants). Also, cigarettes were the drug with the youngest mean age of onset which would still fall on a Guttman scale with other drugs shown to scale in previous research. Finally, it was shown that having tried only cigarettes or marijuana made one significantly more likely to be using other drugs two years later.