THE EFFECTS OF TBI SEVERITY AND PTSD ON SUBJECTIVE COGNITIVE DECLINE IN OLDER VETERANS

Abstract

Abstract Both post-traumatic stress disorder (PTSD) and traumatic brain injury (TBI) have been linked to subjective cognitive complaints; however, less is known about the unique relationships of PTSD symptoms and TBI severity with domain-specific subjective cognitive declines in older Veterans. The current study included 215 Vietnam-Era Veterans from the Department of Defense-Alzheimer’s Disease Neuroimaging Initiative (age M=69.62 years, SD=4.30). General linear models, adjusting for age, education, apolipoprotein E ε4 status, self-reported health, MMSE score, and depressive symptoms, examined the unique effects of PTSD symptoms (measured using the Clinician-Administered PTSD Scale) and TBI severity (none, mild, moderate/severe) on subjective cognitive decline measured using the Everyday Cognition (ECog) measure. Greater current PTSD symptoms were associated with greater subjective cognitive declines on the ECog total score (t=.198, p=.009) as well as memory (t=.197, p=.008), language (t=.228, p=.004), and visuospatial (t=.216, p=.007) subscales. Compared with participants with no TBI, mild TBI was associated with greater subjective cognitive decline on the ECog total score (t=.329, p=.026) as well as the language (t=.334, p=.030) and divided attention (t=.411, p=.007) subscales, while moderate-to-severe TBI was associated with greater subjective declines in planning (t=.291, p=.049) and divided attention (t=.320, p=.032). There was no interaction between PTSD and TBI severity on ECog scores. Results suggest that PTSD symptoms and mild versus moderate/severe TBI differentially impact specific domains of subjective cognitive decline. Future work should investigate how repetitive TBI may modify these relationships, and whether PTSD and TBI severity are associated with objective cognition and quality of life in older Veterans.