The Cohort III interview included a complete assessment of lifetime DSM-IV cannabis abuse and dependence. The Cohort II interview included an abbreviated assessment containing two abuse criteria (use in physically hazardous situations, use interfering with role obligations) and four dependence criteria (using more frequently or for longer periods than intended, tolerance, continued use despite use causing emotional problems, recurrent desire to cut down on use). This abbreviated assessment has been previously utilized (see Lynskey et al., 2006). To maintain consistency across cohorts, a six-item symptom count using the restricted CUD criteria was created. Cannabis use disorder was defined conditionally, such that (a) the symptom count was constructed for respondents who endorsed having ever used cannabis, and (b) abstainers were coded as missing. The variable was skewed and kurtotic and was log-transformed (after transformation: skewness=1.23, kurtosis=−0.04). The number of symptoms ranged from 0 to 6 in men (M=1.09, SD=1.71) and women (M=0.70, SD=1.43) and the average number of symptoms in the sample was 0.88 (SD=1.58). The prevalence of individuals endorsing one or more symptoms was 38.1%, 25.5%, and 31.2% for men,
