Traumatic Brain Injury (TBI) is linked to psychiatric and neurobehavioral problems. There has been a focus on the cognitive, affective, and behavioral effects of severe TBI, which are considered to be more harmful than physical effects. Moderate and severe TBI have been found to cause personality changes, including impulsivity, severe irritability, affective instability, and apathy. On the other hand, mild TBI has a range of affective symptoms, including suicide, posttraumatic stress disorder (PTSD), and major depressive disorder. Head impacts, now more common in sports, have emotional and behavioral effects. The article discusses the epidemiology of psychiatric and neurobehavioral problems after TBI in military, civilian, and athletic contexts.