The self-report Drinking and Drug History (DDHx, Zucker et al., 1990, Zucker and Fitzgerald, 1994) was completed by participants annually since age 11. Data used were collected mean 0.83±1.04 years from scan and reflect extent of drug involvement since age 11. Total drinking in past 6 months was calculated from DDHx counts of drinking days/month multiplied by drinks usually consumed/drinking day. Alcohol problems (AP) were number of drinking problems (out of possible 37 items) ever reported by the subject since age 11. Number of illicit drugs ever used was quantified from a list of 18 drugs ever reported using over their lifetime. Cigarette smoking was determined from DDHx assessment or the more proximal pre-scan screening question, “Do you smoke?”, and coded: 0 (non-smoker, n=23) and 1 (smoker, n=44). Substance use data were not normally distributed (Kolmogorov-Smirnov (KS) test, Z’s>1.91, p’s<0.032) and were not normalized with standard transformations (square root, inverse; KS Z’s>1.34, p’s<0.035), and were therefore treated as a non-parametric variables. Age of onset was determined from the first annual DDHx on which the target reported first drink age and was normally distributed (KS test, Z=1.123, p=0.160).
