Baseline executive functioning moderates treatment-related changes in quality of life in veterans with posttraumatic stress disorder and comorbid traumatic brain injury

Neural activity during working memory predicts clinical response to computerized executive function training prior to cognitive processing therapy

BACKGROUND

Executive dysfunction, including working memory deficits, is prominent in posttraumatic stress disorder (PTSD) and can impede treatment effectiveness. Intervention approaches that target executive dysfunction alongside standard PTSD treatments could boost clinical response. The current study reports secondary analyses from a randomized controlled trial testing combined PTSD treatment with a computerized training program to improve executive dysfunction. We assessed if pre-treatment neurocognitive substrates of executive functioning predicted clinical response to this novel intervention.

METHODS

Treatment-seeking veterans with PTSD (N = 60) completed a working memory task during functional magnetic resonance imaging prior to being randomized to six weeks of computerized executive function training (five 30-minute sessions each week) plus twelve 50-minute sessions of cognitive processing therapy (CEFT + CPT) or placebo training plus CPT (PT + CPT). Using linear mixed effects models, we examined the extent to which the neurocognitive substrates of executive functioning predicted PTSD treatment response.

RESULTS

Results indicated that veterans with greater activation of working memory regions (e.g. lateral prefrontal and cingulate cortex) had better PTSD symptom improvement trajectories in CEFT + CPT v. PT + CPT. Those with less neural activation during working memory showed similar trajectories of PTSD symptom change regardless of treatment condition.

CONCLUSIONS

Greater activity of frontal regions implicated in working memory may serve as a biomarker of response to a novel treatment in veterans with PTSD. Individuals with greater regional responsiveness benefited more from treatment that targeted cognitive dysfunction than treatment that did not include active cognitive training. Clinically, findings could inform our understanding of treatment mechanisms and may contribute to better personalization of treatment.

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

OBJECTIVE

Post-9/11 Veterans endorse greater self-reported functional disability than 80% of the adult population. Previous studies of trauma-exposed populations have shown that increased post-traumatic stress disorder (PTSD) and depressive symptoms are consistently associated with greater disability. Additionally, poorer cognitive performance in the domain of executive functions, particularly inhibitory control, has been associated with disability, though it is unclear if this effect is independent of and/or interacts with PTSD and depression.

METHOD

Three overlapping samples of n = 582, 297, and 183 combat-deployed post-9/11 Veterans completed comprehensive assessments of executive functions, PTSD and depressive symptoms, and self-reported World Health Organization Disability Assessment Schedule-II (WHODAS II).

RESULTS

Poorer performance on measures of inhibitory control (Delis-Kaplan Executive Functioning System Color-Word Interference-CWI Test and gradual-onset Continuous Performance Test-gradCPT), but not other executive functions, were significantly associated with greater disability on the WHODAS II (ρ's = -.13 and -.13, p = .002 and .026, respectively). CWI inhibitory control measures accounted for unique variance in disability after controlling for PTSD and depressive symptoms (R2 change = 0.02, p < .001). Further, CWI significantly moderated the effect of depressive symptoms on disability, such that better inhibitory control weakened the relationship between depression and disability.

CONCLUSIONS

Inhibitory control deficits are uniquely associated with increased disability in combat-deployed post-9/11 Veterans, and better inhibitory control abilities may serve as a protective factor for depressive symptoms leading to increased disability.

KEY POINTS