Relationship between white matter integrity and serum cortisol levels in drug-naive patients with major depressive
Xiaodan Liu1, Keita Watanabe1, Shingo Kakeda2
1Xiaodan Liu, MD, Department of Radiology, University of Occupational and Environmental Health, Fukuoka, Japan, and Medical Imaging Center, 1st Affiliated Hospital of Jinan University, Guangzhou, China; Keita Watanabe, MD, Shingo Kakeda, MD, PhD, Department of Radiology, University of Occupational and Environmental Health, Fukuoka, Japan; Reiji Yoshimura, MD, PhD, Department of Psychiatry, University of Occupational and Environmental Health, Fukuoka, Japan; Osamu Abe, MD, PhD, Department of Radiology, Nihon University School of Medicine, Tokyo, Japan; Satoru Ide, MD, Department of Radiology, University of Occupational and Environmental Health, Fukuoka, Japan; Kenji Hayashi, MD, Asuka Katsuki, MD, Wakako Umene-Nakano, MD, PhD, Department of Psychiatry, University of Occupational and Environmental Health, Fukuoka, Japan; Rieko Watanabe, MD, Issei Ueda, MD, Department of Radiology, University of Occupational and Environmental Health, Fukuoka, Japan; Jun Nakamura, MD, PhD, Department of Psychiatry, University of Occupational and Environmental Health, Fukuoka, Japan; Yukunori Korogi, MD, PhD, Department of Radiology, University of Occupational and Environmental Health, Fukuoka, Japan.
Background:
Higher daytime cortisol levels because of a hyperactive hypothalamic-pituitary-adrenal axis have been reported in patients with major depressive disorder (MDD). The elevated glucocorticoids inhibit the proliferation of the oligodendrocytes that are responsible for myelinating the axons of white matter fibre tracts.
Aims:
To evaluate the relationship between white matter integrity and serum cortisol levels during a first depressive episode in drug-naive patients with MDD (MDD group) using a tract-based spatial statistics (TBSS) method.
Method:
The MDD group (n = 29) and a healthy control group (n = 47) underwent diffusion tensor imaging (DTI) scans and an analysis was conducted using TBSS. Morning blood samples were obtained from both groups for cortisol measurement.
Results:
Compared with the controls, the MDD group had significantly reduced fractional anisotropy values (P<0.05, family-wise error (FWE)-corrected) in the inferior fronto-occipital fasciculus, uncinate fasciculus and anterior thalamic radiation. The fractional anisotropy values of the inferior fronto-occipital fasciculus, uncinate fasciculus and anterior thalamic radiation had significantly negative correlations with the serum cortisol levels in the MDD group (P<0.05, FWE-corrected).
Conclusions:
Our findings indicate that the elevated cortisol levels in the MDD group may injure the white matter integrity in the frontal-subcortical and frontal-limbic circuits.
