Cases were recruited from opioid replacement therapy (ORT) clinics in the greater Sydney region and required to be age 18 or older, understand English, and have participated in ORT for opioid dependence. Those who reported recent suicidal intent or current psychosis were excluded. Individuals recruited from geographic areas in proximity to ORT clinics, termed “neighborhood controls”, were excluded for having used opioids recreationally more than five times over their lifetime (data are included from 23 controls who denied this level of opioid use at screening, but reported greater use with no dependence symptoms at interview). All other inclusion and exclusion criteria were identical to cases. Institutional review board (IRB) approval was obtained from University of New South Wales, Washington University School of Medicine, Queensland Institute of Medical Research, and all New South Wales area health service ethics committees governing participating clinics. Data were collected between 2004 and 2008. Participants provided written informed consent and were reimbursed AU$50.00. Data reported here include only those individuals (N=1749) who endorsed at least one form of trauma exposure in the interview’s PTSD section; those
