Inhibitory Control and Alcohol Use History Predict Changes in Posttraumatic Stress Disorder Symptoms

Objective: Posttraumatic stress disorder (PTSD) is associated with significant disability and can become chronic. Predictors of PTSD symptom changes over time, especially in those with a PTSD diagnosis, remain incompletely characterized. Method: In the present study, we examined 187 post-9/11 veterans (M-age = 32.8 years, 87% male) diagnosed with PTSD who performed two extensive clinical and cognitive evaluations approximately 2 years apart. Results: We found that greater PTSD symptom reductions over time were related to lower lifetime drinking history and better baseline inhibitory control ability (Color-Word Inhibition and Inhibition/Switching), though not performance on other executive function tasks. Further, groups with reliably Improved, Worsened, or Chronic PTSD symptoms demonstrated significant differences in baseline inhibitory control and lifetime drinking history, with marked drinking differences starting in the early-to-mid 20s. We also found that PTSD symptom changes showed little-to-no associations with changes in inhibitory control or alcohol consumption. Conclusions: Together, these findings suggest that, in those diagnosed with PTSD, inhibitory control and alcohol use history reflect relatively stable risk/resiliency factors predictive of PTSD chronicity.Key Points Question: In individuals with a diagnosis of PTSD, are changes in PTSD symptoms over time predicted by baseline inhibitory control and cognitive performance as well as current/lifetime alcohol consumption and other clinical variables? Findings: Lower lifetime drinking history and better baseline inhibitory control are associated with greater PTSD symptom improvements across 2 years. Importance: Inhibitory control and lifetime drinking history represent contributing mechanisms in the chronicity of PTSD symptoms and provide targets for interventions. Next Steps: Future research should more comprehensively characterize inhibitory control (e.g., response inhibition, memory suppression, using nonemotional and emotional or trauma-related material) to understand what best predicts PTSD symptom changes as well as examine the effectiveness of cognitive and pharmacological approaches to improving inhibitory control.