Functional outcome in TBI I: neuropsychological, emotional, and behavioral mediators.

Literature exists to suggest that the severity of traumatic brain injury (TBI) is positively associated with the severity of functional impairment. However, potential mediators of this relationship have not been studied systematically. In the present study, we evaluated a model hypothesized to explain the relationship between TBI severity and functional impairment in 87 patients with moderate-to-severe TBI, studied longitudinally. Using structural equation modeling, we found that only neuropsychological status (but not emotional or behavioral difficulties) consistently mediated the relationship between TBI severity and functional outcome at 12-months post-injury. These findings suggest that, of the factors examined here, neurocognitive compromise plays the most prominent role in mediating post-TBI adaptive functioning in moderate-to-severe TBI, which has important implications for post-injury interventions.