History of mild to moderate traumatic brain injury and aggression in physically healthy participants with and without personality disorder.

We tested the hypothesis that history of mild to moderate traumatic brain injury (TBI) is associated with higher scores on psychometrically valid measures of aggression and impulsivity in both normal control (NC), and personality disordered (PD), participants. Participants were 458 research volunteers in whom history of mild TBI and measures of both aggression and impulsivity were collected. Aggression, but not impulsivity, scores were elevated as a function of TBI and PD status; there was no interaction between mild TBI and subject group. These data suggest that lifetime history of mild TBI is associated with history of aggression regardless of history of psychiatric disorder.