dependence and abuse if they met the criteria for these disorders for the first time in either of the two time periods between Wave 1 and Wave 2. Because of evidence that individuals with dependence can develop abuse without dependence, and vice versa (Grant et al., 2008; Hasin et al., 1990; Schuckit et al., 2001), we chose not to impose the DSM-IV hierarchy of these disorders in which a diagnosis of dependence preempts abuse. Thus, individuals were eligible for the incidence of abuse even if classified with dependence during the same or an earlier time period.
