Posttraumatic stress disorder (PTSD) patients experience symptoms which implicate dysfunction of emotional memory
circuits, and possible damage of the amygdala. Laterality differences in activity of the amygdala have been reported
in PTSD patients, with presumed adaptive plasticity in the hippocampus and the amygdala. The aim of this study was to
investigate possible interhemispheric differences of amygdalar volume in chronic PTSD patients, with calculation of
right-to-left volume ratios. Bilateral magnetic resonance (MR) volumetry was applied in 11 chronic PTSD patients. The
mean right amygdalar volume of our patients was significantly smaller than the left one (p=0.031), with the right-to-left
volume ratio of 0.96±0.06. This tendency towards smaller right amygdala may be an acquired effect as a result of
stress-induced plasticity, however we can not exclude the possibility of a predisposing condition
