Trauma, hippocampus and memory. A critical evaluation
background Memory impairments are frequently observed in patients with a posttraumatic stress disorder. According to some authors, these impairments are due to hippocampal damage brought about by traumatic stress.
aim To make a critical evaluation of research into hippocampal abnormalities and memory impairments in posttraumatic stress disorder.
method Using Psycinfo and Medline, articles were identified and studied in which posttraumatic stress disorder patients were compared to control subjects with regard to the volume of their hippocampus and their memory performance. These articles were then judged on their methodological quality.
results Although most studies show that posttraumatic stress disorder patients have a smaller hippocampus volume than controls, the size of the hippocampus does not seem to be associated with memory performance. Some studies reveal methodological flaws. In addition, there are indications that hippocampal abnormalities should be regarded as a risk factor for posttraumatic stress disorder rather than as a result of posttraumatic stress disorder.
conclusion No firm conclusion can be drawn regarding the causal relation between traumatic stress, hippocampal abnormalities and memory performance. Further research in this area seems necessary.