The use of proton magnetic resonance spectroscopy in PTSD research--meta-analyses of findings and methodological review.

Different neuroimaging techniques provided evidence for structural and functional brain alterations in posttraumatic stress disorder (PTSD). Due to technical improvements, especially concerning localization techniques and more reliable analysis methods, one technique, proton magnetic resonance spectroscopy ((1)H-MRS), has increasingly become of interest because it allows further insight into metabolic mechanisms that may contribute to these alterations. The aim of this article is, therefore, to review recent studies utilizing (1)H-MRS of the hippocampus and other brain structures in PTSD. Using meta-analytic methods, we attempted to answer the question if PTSD, as compared to different types of control samples, is accompanied by altered neurometabolite ratios and concentrations in the tissue of different brain regions. A second intent was to review methodological aspects to advise on a minimal standard for reliable results with respect to the application of (1)H-MRS in PTSD. Finally, we discussed the implications of the findings with respect to current PTSD models and future research.