(PS10-10) Trauma-related Alterations in Arousal and Reactivity Predicts Alcohol Use Disorder (AUD) Severity Among Veterans with PTSD, AUD and Polysubstance Use

Prior research has examined the unique relationship between posttraumatic stress disorder (PTSD) symptom clusters and substance use, with much of the research focusing on specific substance use disorders in isolation (i.e. alcohol use alone). However, there is minimal research on the relationship between PTSD cluster symptoms when looking at alcohol use disorder (AUD) alone in comparison to polysubstance use. The findings regarding the relationship between alcohol use and PTSD symptom clusters have been mixed and only one study used clinician-rated DSM-5 symptoms of PTSD. Concurrently, research on polysubstance use in relation to PTSD clusters has mixed results with a majority of the studies using DSM-IV criteria. The current study examines the relationship of PTSD symptom cluster severity and AUD severity among veterans with PTSD and AUD only and PTSD and polysubstance use. We hypothesized that overall PTSD symptoms would be related to AUD severity but did not make a priori hypotheses about which specific PTSD symptom clusters would be related to AUD severity, given the inconsistent previous literature.

Participants were Veterans from fourteen VA medical centers across the United States, with 279 having PTSD and AUD only and 76 having PTSD and polysubstance use, specifically AUD along with either cannabis use disorder, opioid use disorder, or both. PTSD symptoms, depression symptoms and AUD severity were assessed using the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5), Patient Health Questionnaire-9 (PHQ-9), and the Structured Clinical Interview for DSM-5 (SCID-5). Multiple linear regressions were conducted to analyze which PTSD symptom clusters significantly predicted AUD severity controlling for depression severity and any demographic and military variables that were significantly associated with a PTSD symptom cluster or AUD severity. In the AUD only group, when controlling for age, gender, race, income, years of military service, and depression, race and alterations in arousal and reactivity significantly predicted AUD severity (β = .17, p = .010; β = .23, p </em>= .002, respectively), accounting for 12.4% of variance in AUD severity. In the polysubstance use disorder group, when controlling for depression, alterations in arousal and reactivity significantly predicted AUD severity (β = .32, p = .017) and accounted for 9.3% of variance in AUD severity. Results indicate that trauma-related alterations in arousal and reactivity are more closely related to AUD severity than other PTSD symptom clusters and is consistent across samples of veterans with AUD only and polysubstance users. These findings are in line with the self-medication hypothesis which proposes that individuals engage in substance use to reduce psychological distress, such as heightened arousal, and that an individual’s preferred drug has psychopharmacologic specificity. For instance, individuals experiencing alterations in arousal and reactivity may be using alcohol, which acts as a depressant of the central nervous system, in order to minimize or alleviate these symptoms temporarily as a maladaptive coping mechanism. Overall, among veterans with PTSD, alterations in arousal and reactivity may be an important treatment target in reducing AUD severity.