have measured heaviness of cannabis use in terms of number of days used per week or month, whereas we queried total number of times used, our results mirror the patterns reported in the literature: substantial elevations in risk occur as frequency of use moves from experimentation to moderate to heavy use (Coffey et al., 2002; Nocon et al., 2006). Our finding that 21.8% of women with AD and 27.1% of men with AD met cannabis dependence criteria also coincides with previous reports of elevated rates of cannabis dependence among alcohol-dependent individuals (Degenhardt and Hall, 2003; Xian et al., 2008).
