Contingent negative variation in acute trauma patients: A prospective exploratory study.

It is still unclear why some individuals completely recover after an acute trauma and others develop a long-lasting post-traumatic stress disorder (PTSD). This study investigates whether the contingent negative variation (CNV) - a slow negative event-related potential - may be associated with the occurrence of PTSD after acute trauma. CNV (auditory 2-stimulus reaction time paradigm) was recorded within one month as well as 6 months after an acute trauma (dangerous or grave physical injuries, witnessing of attempted suicide or murder, robbery, extortion, accidents, heavy illness, death or loss of an important person, hostage-taking) in 39 otherwise healthy adults and compared with CNV recordings in 38 healthy control subjects without potentially traumatizing experience in their history. According to their subsequent clinical course, these subjects were divided into two groups: participants who recovered completely 1 month after the trauma (PTSD- group, n = 31), and those who began to experience PTSD (PTSD+ group, n = 8). Patients from both trauma groups were characterized by a significantly longer reaction time immediately after the trauma. The PTSD+ group demonstrated lower amplitudes of the late CNV component immediately and six months after the trauma compared with the PTSD- and the control group. Whether the lower CNV amplitudes in patients who develop PTSD after the acute trauma, which is already present in the first days after the trauma, may be related to a higher risk for development of PTSD in these subjects, this has to be clarified in further prospective studies.