Postconcussional disorder and loss of consciousness

Postconcussional disorder (PCD) has been described in the psychiatric, neurological, neuropsychological, and rehabilitation medicine literature for many years. PCD has recently been introduced into DSM-IV, appearing in an appendix that contains a number of proposals for new categories and axes that were suggested for possible inclusion in DSM-IV. There are some major difficulties with the proposed criteria for PCD. This article explores some of these difficulties, particularly focusing on the criteria of loss of consciousness (LOC). A review of the literature demonstrates that LOC is not necessary for PCD to occur. The major difficulty with the DSM-IV criteria is the definition of concussion. The article suggests that, instead, the criteria for mild traumatic brain injury, as defined by the American Congress of Rehabilitation Medicine, may be more appropriate.