In reply
Cottler and Grant et al raise 2 concerns regarding the estimates of alcohol and illicit drug dependence in the NCS-R: (1) that the algorithm required respondents to endorse at least 1 lifetime abuse symptom for a diagnosis of dependence, yielding an underestimate of DSM-IV1 dependence; and (2) that our approach of aggregate assessment of drug dependence rather than separate assessment of individual classes of illicit drugs is inconsistent with the fact that DSM-IV does not have a category of generic drug dependence.