Postconcussive, posttraumatic stress and depressive symptoms in recently deployed U.S. Army soldiers with traumatic brain injury

Prior studies raise questions about whether persistent postconcussive symptoms (PCS) are differentiable from mental health sequelae of traumatic brain injury (TBI). To investigate whether PCS represented a distinct symptom domain, we evaluated the structure of post-concussive and psychological symptoms using data from The Army STARRS Pre/Post Deployment Study, a panel survey of three U.S. Army Brigade Combat Teams that deployed to Afghanistan. Data from 1229 participants who sustained probable TBI during deployment completed ratings of past-30-day post-concussive, posttraumatic stress, and depressive symptoms three months after their return. Exploratory factor analysis (EFA; n = 300) and confirmatory factor analysis (CFA; n = 929) of symptom ratings were performed in independent subsamples. EFA suggested a model with 3 correlated factors resembling PCS, posttraumatic stress, and depression. CFA confirmed adequate fit of the 3-factor model (CFI = .964, RMSEA = .073 [.070, .075]), contingent upon allowing theoretically defensible cross-loadings. Bifactor CFA indicated that variance in all symptoms was explained by a general factor (λ = .36 -.93), but also provided evidence of domain factors defined by (a) reexperiencing/hyperarousal, (b) cognitive/somatic symptoms, and (c) depressed mood/anhedonia. Soldiers with more severe TBI had higher cognitive/somatic scores, whereas soldiers with more deployment stress had higher general and reexperiencing/hyperarousal scores. Thus, variance in PCS is attributable to both a specific cognitive/somatic symptom factor and a general factor that also explains variance in posttraumatic stress and depression. Measurement of specific domains representing cognitive/somatic symptoms, reexperiencing/hyperarousal, and depressed mood/anhedonia may help clarify the relative severity of PCS, posttraumatic stress, and depression among individuals with recent TBI.