Background: Given that on the one side considerable similarities between hypochondriasis and obsessive- compulsive disorder (OCD) by means of sharing a number of features, including intrusive thoughts and repeated checking (Barsky, 1992), on the other side similar structural neuroimaging data that found hypochondriac patients to have significantly smaller mean left and right OFC, and greater left thalamus volumes compared to those of healthy controls. Aims: We considered to investigate the hippocampal neurochemicals, found changed in OCD patients, in hypochondriac patients. Methods: Fifteen patients with hypochondriasis, recruited from our out- or in-patient clinics, were compared with 15 healthy control comparisons in regard to proton magnetic resonance spectroscopy (1H-MRS) imaging of hippocampus. Results: The patients with hypochondriasis had lower right and left NAA/CHO, and NAA/CRE, and near-significant lower right CHO/CRE hippocampal ratios than healthy matched comparison subjects. Conclusion: The data of the present investigation in patients with hypochondriasis provide preliminary evidence of lower right and left NAA/CHO, and NAA/CRE, near-significant lower right CHO/CRE hippocampal ratios, revealing neurochemical alterations in hippocampus and a further support the notion that hypochondriasis shares a variety of neurobiological similarities with OCD.
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