The Role of Functional Health Literacy in Terms of Hazardous Alcohol Use in Adults with Probable Posttraumatic Stress Disorder and Alcohol Use Disorder

Objective: Co-occurring posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD) represents a prevalent and problematic comorbidity. Functional health literacy (FHL) may play a role in this comorbidity based on its previously documented role in hazardous drinking. The current study examined functional health literacy (FHL) regarding hazardous drinking among a sample with probable posttraumatic stress disorder (PTSD) and alcohol use disorder (AUD). Methods: The current study is a secondary analysis of data from a project studying the transdiagnostic risk and maintenance factors of PTSD and hazardous alcohol use among people with probable PTSD and AUD. Participants were 565 nationally recruited adults with probable PTSD and hazardous alcohol use (52.2% female, 68.8% non-Hispanic White, average age = 39.2 years ± 10.9 years). Linear regression models were conducted regressing hazardous alcohol use onto PTSD symptoms and FHL scores. An interaction term between FHL and PTSD symptoms was included in the regression models with age, biological sex, race, and income included as covariates. Results: Low FHL maintained a statistically significant role in predicting greater hazardous drinking (p < .001) even in the context of posttraumatic stress. High posttraumatic stress also emerged as a statistically significant predictor of hazardous alcohol use (p < .001). The interaction term between FHL and PTSD was not found to be a significant predictor of hazardous alcohol use (p = .222). Conclusion: FHL may be a relevant variable for better understand hazardous drinking among persons with comorbid PTSD and AUD.