Participants were also asked questions about behaviors that could reflect either substance dependence or substance abuse for each substance. The items were modeled after items in the Composite International Diagnostic Interview (CIDI) version 2.1 (Robins et al. 1989) and included “Have you tried to stop using [a substance] and found you could not?” (used for all substances), “When you used [this substance], did you get high?” and “Have you found that you can’t get as high on [this substance] as you used to?” (used for alcohol and marijuana), “Have you ever gone to school or work when you were high on [this substance]?” and “Have you ever had any problems related to school or work, such as not doing assignments or forgetting things because of [this substance]?” (used for marijuana). All those questions were answered by yes or no. For the “… did you get high?” item, an additional question followed for those who responded in the affirmative, asking “How high did you get?” Participants responded on a 3-point scale, indicating if they got “a little,” “quite a bit,” or
