There were a total of 41 participants who completed the NEO-PI-R profiles at baseline and 12 months. Extraversion and Openness decreased from baseline (as compared with pre-TBI traits) to 12 months. The changes were small in magnitude, with percentile decreases of 10.9 points for Extraversion and 5.1 points for Openness. After correcting for multiple comparisons, there were no statistically significant associations between post-TBI personality traits and baseline clinical variables, including age, gender, living situation, employment, race, education, presence of frontotemporal lesion (as assessed by computerized tomography scans), Lawton Activities of Daily Living Scale, Glasgow Coma Scale score, or the presence of any psychiatric diagnosis post-TBI, including substance abuse disorder, mood disorder, anxiety disorder, or personality change. These findings are similar to those of Kurtz et al.,4 who found stability of personality traits post-TBI. Our current results suggest that a relatively small change in personality traits post-TBI acts as a marker of traumatic brain injury, but not injury severity or complications. We recommend that future research include better-powered studies of longer duration, using personality assessments as close to the time of injury as possible and using more sensitive imaging methods, including MR and diffusion tensor imaging.