Impact of Alcohol Use Disorder Comorbidity on Defensive Reactivity to Errors in Veterans with Post-traumatic Stress Disorder

摘要

Converging lines of evidence suggest that individuals with comorbid post-traumatic stress disorder (PTSD) and alcohol use disorder (AUD) may be characterized by heightened defensive reactivity, which serves to maintain drinking behaviors and anxiety/hyperarousal symptoms. Notably, however, very few studies have directly tested whether individuals with PTSD and AUD exhibit greater defensive reactivity compared with individuals with PTSD without AUD. The aim of the current study was to therefore test this emerging hypothesis by examining individual differences in error related negativity (ERN), an event-related component that is larger among anxious individuals and is thought to reflect defensive reactivity to errors. Participants were sixty-six military veterans who completed a well-validated flanker task known to robustly elicit the ERN. Veterans were comprised of three groups: controls (i.e., no PTSD or AUD), PTSD-AUD (i.e., current PTSD but no AUD), and PTSD+AUD (i.e., current comorbid PTSD and AUD). Results indicated that in general, individuals with PTSD and controls did not differ in ERN amplitude. However, among individuals with PTSD, those with comorbid AUD had significantly larger ERNs than those without AUD. These findings suggest that PTSD+AUD is a neurobiologically unique subtype of PTSD and the comorbidity of AUD may enhance defensive reactivity to errors in individuals with PTSD.