Consistent with other work (Johnston, O’Malley, & Bachman, 2000), youths were asked about frequency of substance use in the past month. The items were, “During the past month, how many times have you: drunk beer, wine, wine coolers, whiskey, gin, or other liquor; had three or more drinks of alcohol at one time; smoked marijuana?” Responses to these three items were summed to form a past-month substance use index, a procedure that is consistent with prior research (Brody & Ge, 2001; Hays, Widaman, DiMatteo, & Stacy, 1987; Needle, Su, & Lavee, 1989; Newcomb & Bentler, 1988; Wills et al., 2007). Cronbach’s alpha for the scale was .65.
