Study Sample and Procedures

The NESARC-III includes 36,309 community-dwelling US residents aged 18 and older not currently on active-duty in the military (Grant et al., 2014). Data collection took place from 2012 to 2013 and used multi-stage probability sampling to include a representative sample. Counties or groups of contiguous counties were the primary sampling units; census blocks the secondary sampling units, and households within census blocks the tertiary sampling units. Eligible adults were randomly selected within households (Grant et al., 2015). Several racial/ethnic minority groups (Hispanic, Black, Asian) were oversampled. The data were weighted to represent the US population and adjusted for non-response. The overall response rate was 60.1%, similar to other US national surveys (American Community Survey, 2012). The current study involves respondents who met criteria for both lifetime PTSD and a lifetime SUD (n = 1,349) with the following SUDs included: alcohol, sedative/tranquilizers, cannabis, stimulants, cocaine, non-heroin opioid, heroin, hallucinogens, club drugs, and solvent/inhalants (note: tobacco use disorder was not included). NESARC-III data were collected via in-person structured interviews by non-clinicians.

The VA Puget Sound Human Subjects IRB determined the study exempt from oversight.