Post-traumatic stress disorder: An overview and its relationship to closedhead injuries

While exposure to traumatic psychological and physical trauma can produce p ost-traumatic stress disorder (PTSD), multiple factors determine whether a person will develop PTSD following trauma exposure. Such factors include, b ut are not limited to, female gender, social disadvantage, childhood advers ity, genetic predisposition, and substance abuse. PTSD has a high rate of c omorbidity with psychiatric, substance abuse, and somatization disorders. P ersons with PTSD experience profound and persistent alterations in their ph ysiological reactivity to internal and external stimuli which prevents them from utilizing their emotions to process incoming information. These patie nts have chronically high levels of sympathetic nervous system activity and low levels of glucocorticoids to cope with stress and modulate their catec holamine levels. Neuropsychological assessment of patients with PTSD depend s to a large degree on the sensitivity of the measures which are utilized a nd a pre-existing history of learning disabilities, head trauma, and/or neu rological disorders. While closed head injuries (CHI) are unlikely to produ ce PTSD symptoms, persons with CHI are likely to develop PTSD symptoms if t hey are exposed to trauma prior to the onset of retrograde amnesia or after the resolution of post-traumatic amnesia. If the traumatic event occurs wh ile the patient with CHI is amnestic or unconscious, they are unlikely to d evelop PTSD symptoms. The liberal criteria used to diagnose mild CHI is lik ely to result in patients with acute stress disorders being misdiagnosed wi th CHI as a result of their dissociative symptoms which reduce their awaren ess and encoding of the traumatic event.