Inhibitory Control and Alcohol Use History Predict Changes in Post-traumatic Stress Disorder Symptoms

Abstract

Post-traumatic stress disorder (PTSD) is a prevalent and disabling condition occurring frequently among Veterans. However, among those diagnosed with PTSD, predictors of changes in PTSD symptoms over time remain incompletely characterized. In the current study, we examined 187 post-9/11 Veterans (Mean baseline age = 32.8 years, 87% male) diagnosed with PTSD who participated in two extensive clinical and cognitive evaluations approximately two years apart. Our analyses focused on the association between baseline measures predicting both continuous changes in PTSD symptoms and differences between groups with Improved, Chronic, and Worsened PTSD symptoms, defined by applying clinically meaningful and reliable change approaches. We found that better baseline inhibitory control (Color-Word Inhibition and Inhibition/Switching) and lower lifetime drinking history independently predicted greater PTSD symptom improvements over the two-year period, though current drinking and other clinical and cognitive variables were not significant predictors. Consistent with this, the Improved, Worsened, and Chronic PTSD groups demonstrated significant differences in baseline inhibitory control performance and lifetime drinking history, with the largest differences in drinking behavior in the early-to-mid 20s. We also found that PTSD symptom improvements were not significantly associated with improvements in inhibitory control or appreciable reductions in alcohol use. Together, these findings suggest that alcohol use and inhibitory control may reflect clinically important pre-existing factors rather than effects of PTSD symptomatology. These findings have implications for the treatment of PTSD, including monitoring vulnerable individuals at risk for more chronic PTSD and novel interventions targeting inhibitory control.

Poorer Inhibitory Control Uniquely Contributes to Greater Functional Disability in Post-9/11 Veterans

“…The current study is part of an ongoing longitudinal study that has consistently found significant associations between PTSD/depressive symptoms and functional disability (Bernstein et al, 2022) as well as inhibitory control and PTSD (DeGutis et al, 2015;DeGutis et al, 2022).…”

“…With regard to PTSD, poorer predeployment inhibitory control ability on the go/no-go gradual-onset continuous performance task (gradCPT) has been associated with a greater likelihood of Veterans developing PTSD post-deployment (Samuelson et al, 2020). Inhibitory control abilities may allow individuals to disengage from or inhibit their responses to trauma-related triggers in their environment or memory, which may reduce the likelihood of developing more persistent PTSD symptoms (Aupperle et al, 2012;Catarino et al, 2015;DeGutis et al, 2022). Further, in those with PTSD, trauma-related or emotional stimuli may become considerably more salient and may overwhelm inhibitory control abilities (Ashley et al, 2013;Bardeen & Read, 2010), which could further exacerbate pre-existing inhibitory control deficits.…”

Smaller Hippocampal Subfield Volumes Predict Greater Improvements in Posttraumatic Stress Disorder Symptoms Over Two Years

“…For example, in a combat-exposed sample with and without PTSD, Karstoft et al (2013) identified four distinct trajectories: chronic (persistent symptoms), recovering (gradually declining symptoms), delayed onset (increase in symptoms following a delay), and resilience (initial low level of symptoms that remain low or subside). Though studies have looked at predictors of PTSD symptom changes (e.g., inhibitory control, DeGutis et al, 2023;depression, Sripada et al, 2017;alcohol abuse, Lee et al, 2020;executive functioning, Jagger-Rickels et al, 2022), factors that predict PTSD symptom changes require additional characterization. One model of PTSD suggests that variations in certain brain structures and functions may represent neurobiological vulnerabilities, pre-dating the trauma or development of PTSD (e.g., Admon et al, 2013).…”