A volumetric study of amygdala in cancer survivors with intrusive recollections

Background: Intrusive recollections, one of the re-experiencing symptoms of posttraumatic stress disorder (PTSD), frequently occur in cancer survivors rather than the full spectrum of the symptoms of PTSD. Functional neuroimaging studies of PTSD have revealed hyperresponsiveness to threat-related stimuli in the amygdala, but no volumetric studies have ever found alteration in the volume of the amygdala. The aim of the present study was to assess the possibility of structural alteration of the amygdala in cancer survivors with intrusive recollections. Methods: Magnetic resonance imaging volumetric analysis of the amygdala was performed in 35 breast cancer survivors with a history of cancer-related intrusive recollections and 41 control breast cancer survivors who had no such history. The groups were similar in age, height, handedness, alcohol consumption, and medical characteristics except for past major depressive disorder. Results: The total volume of the amygdala was significantly smaller in subjects with a history of intrusive recollections as compared with the control subjects. This finding continued to be significant after controlling for age, height, and major depressive disorder. Conclusions: These results suggest a difference in volume of the amygdala of cancer survivors according to whether they have had cancer-related intrusive recollections.