Pre-deployment personality traits predict prescription opioid receipt over 2-year post-deployment period in a longitudinal cohort of deployed National Guard soldiers

Background: While military service members are at risk for pain conditions, receipt of prescribed opioids is associated with a range of serious adverse outcomes. The goal of this study is to examine the association between pre-deployment personality traits and receipt of prescription opioids after return from deployment. Method: Data were drawn from the Readiness and Resilience in National Guard Soldiers (RINGS) cohort study, an ongoing study of post-deployment health. Participants (N = 522) completed baseline assessments one month prior to deploying to Iraq (2006–2007). At baseline, we assessed personality traits using abbreviated versions of the Personality Psychopathology Five scales from the Minnesota Multiphasic Personality Inventory-2. Follow-up assessments were conducted three months, one year, and two years post-deployment. The primary outcome was total amount of prescribed opioids dispensed from Department of Veterans Affairs outpatient pharmacies in the two-year period following soldiers’ return from deployment. Unadjusted and adjusted negative binomial regression models examined the relationships of pre-deployment personality traits, demographics (age, gender, and rank), baseline trauma symptoms, deployment related risk factors (difficult living/working environment, deployment injury, combat exposure), and post-deployment trauma symptoms with post-deployment opioid prescribing. Results: Disconstraint, negative emotionality, and introversion/low positive emotionality were associated with receipt of more prescribed opioids over the two years after return from deployment. Personality traits measured at baseline remained statistically significantly after adjusting for all eight baseline and deployment risk factors of interest. Conclusions: Understanding how pre-deployment personality traits contribute to post-deployment prescription opioid use could inform efforts to improve veterans’ health.