New fields of research in posttraumatic stress disorder: brain imaging

Purpose of review This paper reviews the most recent literature on brain imaging research in posttraurnatic stress disorder. Neuroimagery identifies several cerebral modifications occurring after a significant psychological trauma, and it contributes to a better understanding of the pathophysiology of posttraurnatic stress disorder. A systematic search of the literature in English, French, German and Dutch from January 2003 to August 2004 was performed on MEDLINE. References cited in all trials were searched iteratively to identify missing studies. Recent findings There appears to be a consensus in brain imaging findings concerning posttraurnatic stress disorder: a diminished volume of the hippocampus uni- or bilateral (on the structural level) and a hyper-reactivity in the amygdala, with a lowered activation in the anterior cingular cortex (at the functional level). These findings are in agreement with several neurological and psychological studies suggesting that hyper-reactivity in the amygdala corresponds to a constellation of symptoms of anxiety in posttraurnatic stress disorder, while the lowered activation of the prefrontal and the anterior cingular cortex could reflect slower extinction of a conditioned emotional response. Summary These neuroimaging findings could contribute to a better understanding of posttraumatic stress disorder. The integration of neurobiological, social and psychological findings may lead to an improved approach to the pathophysiology of posttraurnatic stress disorder and perhaps to the development of new pharmacological treatment. Future studies could integrate the disparate findings among numerous biological systems and propose an integrative structural, functional and endocrinological model.