West at, respectively); whether having different employers of the interviewers affected participant responses is unknown. However, NESARC and NESARC-III were both presented to respondents as voluntary surveys conducted under the auspices of the US government, possibly mitigating this difference. Finally, this study did not examine changes in past-year frequency of use, specific DSM-IV abuse or dependence criteria, severity of disorder, other aspects of use, or risk factors. Future studies should address changes in these to determine whether they assist in explaining the results. The study also did not examine NESARC/NESARC-III differences by DSM-5 severity levels. The DSM-5 marijuana disorder criteria, published in 2013, were not known in 2001, and thus not all DSM-5 criteria were included in the 2001–2002 NESARC.
