Abstract: Objective To explore the main performance of personality change in people with mild psychiatric impairments which due to the brain trauma caused by traffic accidents and its value in assessment of psychiatric impairment. Methods The condition of personality change of patients with traumatic brain injury caused by traffic accident was evaluated by the Scale of Personality Change Post-traumatic Brain Injury （SPCPTBI）. Furthermore, the correlation between the personality change and the degrees of traumatic brain injury and psychiatric impairment were explored. Results In 271 samples, 239 （88.2%） with personality changes. Among these 239 samples, 178 （65.7%）, 46 （17.0%）, 15 （5.5%） with mild, moderate and severe personality changes, respectively. The ratio based on the extent of personality changes to the degree of brain trauma was not significant （P>0.05）, but the total score difference between the groups was significant （P<0.05）. There was no statistical significance between the medium and high severity brain trauma groups. The higher degree of personality changes, the higher rank of mental disabilities. The total score difference of the scale of personality change among the different mild psychiatric impairment group was significant （P<0.05）. The difference between other psychiatric impairment levels had statistical significance（P<0.05） except level 7 and 8. Conclusion The occurrence of personality change due to traumatic brain injury caused by traffic accident was high. Correlations exist between the personality change and the degree of psychiatric impairment. Personality change due to brain trauma caused by traffic accident can be assessed effectively by means of SPCPTBI, and the correlation between the total score and the extent of traumatic brain injury can be found.

Key words: forensic psychiatry, brain injuries, accidents, traffic, personality change, psychiatric impairment