Behavioral and Psychiatric Comorbidities of TBI

Traumatic brain injury (TBI) is associated with a variety of behavioral ­consequences, including symptoms of depression, anxiety, aggression, and impulse control and overlaps with many of the symptoms of post-traumatic stress and post-traumatic stress disorder. There are many challenges to researchers and clinicians, including heterogeneity of the injury, distinguishing premorbid characteristics from the consequences of the TBI, lack of specificity in diagnostic criteria, and the absence of systematic therapeutic trials. In this chapter, we present an overview of the literature on psychiatric and behavioral consequences of TBI, highlighting those studies that investigate the incidence of these conditions, contribution of premorbid functioning to subsequent symptoms, and characteristics of mild TBI ­(frequently referred to as concussion) that provide clues to distinguishing it from other psychiatric comorbidities. Our analysis of the available literature suggests that in some, but not all cases, TBI may diminish inhibitory control over certain behaviors while in others, there may be an exacerbation of clinical expression of psychiatric symptoms. Treatment needs to consider whether there is a unique sensitivity to adverse events in patients who have suffered a TBI and prospective trials should be encouraged.