Morphometric alterations of amygdala and hippocampal regions in patients with hypochondriasis

Hypochondriasis is classified as a somatoform disorder in DSM-IV classification but it has also been considered as a obsessive-compulsive spectrum disorder. Obsessive-compulsive spectrum disorders are characterized as similar to obsessive-compulsive disorder (OCD) in terms of etiology, phenomenology, familial transmission and response to similar pharmacologic or behavioral treatments. Functional and structural neuroimaging studies of hippocampal and amygdalar regions were investigated in the pathophysiology of OCD recently. Hippocampal and amygdalar abnormalities were emphasized in these studies and it has been suggested that these abnormalities may play a role in the pathophysiology of OCD. However little is known about the pathophsiology of hipochondriasis as a obssesive-compulsive spectrum disorder. In our study we aimed to investigate the morphometric alterations of hippocampal and amygdalar regions in the hypochondriacal patients to understand the pathophsiology of the disorder as a obsessive-compulsive spectrum disorder.Volumes of the amygdala and hippocampus were measured by magnetic resonance imaging (MRI) in a sample of 20 patients with DSM-IV hyphochondriasis and 20 healty comparison subjects.In hyphochondriacal patients volumes of the white matter was significantly greater than the controls (p<0.01) and also the left amygdala (p<0.05) and the left hippocampal volumes were significantly greater than the healthy objects (p<0.05).Our results showed volumetric abnormalities in the amygdala and hippocampal regions of the hypochondriacal patients but more investigations are need to support our findings for the conceptualization of hyphocondriasis as a obsessive-compulsive spectrum disorder.Key Words: Hypochondriasis, MRI, morphometric, amygdala, hippocampus