The distribution of substance use measures, educational attainment, and covariates is shown in Table 1. By 1987, 96.8% had completed 12 or more years of education and 24.1% had at least 16 years of education. Based on the 1992 survey, almost all participants were drinkers at some point in their lives, with about one-third having met lifetime criteria for alcohol dependence. Almost 70% of respondents had used nicotine daily at some time, and almost 50% met lifetime criteria for nicotine dependence. About half of the respondents had ever used cannabis, with less than 7% having a lifetime DSM-III-R cannabis dependence diagnosis. In addition, about 10% of respondents had DSM-III-R diagnoses of depression (lifetime), PTSD (lifetime), and conduct disorder before age 16. Almost 40% had served in Southeast Asia.
