Post-traumatic stress disorder and traumatic brain injury.

Disentangling the effects of "organic" neurologic damage and psychological distress after a traumatic brain injury poses a significant challenge to researchers and clinicians. Establishing a link between traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) has been particularly contentious, reflecting difficulties in establishing a unique diagnosis for conditions with overlapping and sometimes contradictory symptom profiles. However, each disorder is linked to a variety of adverse health outcomes, underscoring the need to better understand how neurologic and psychiatric risk factors interact following trauma. Here, we present data showing that individuals with a TBI are more likely to develop PTSD, and that individuals with PTSD are more likely to develop persistent cognitive sequelae related to TBI. Further, we describe neurobiological models of PTSD, highlighting how patterns of neurologic damage typical in TBI may promote or protect against the development of PTSD in brain-injured populations. These data highlight the unique course of PTSD following a TBI and have important diagnostic, prognostic, and treatment implications for individuals with a dual diagnosis.