State-Independent Microstructural White Matter Abnormalities in Major Depressive Disorder

Qiangli Dong; Jin Liu; Lingli Zeng; Yiming Fan; Xiaowen Lu; Jinrong Sun; Liang Zhang; Mi Wang; Hua Guo; Futao Zhao; Danfeng Yan; Haolun Li; Weilong Guo; Yan Zhang; Bangshan Liu; Dewen Hu; Lingjiang Li

doi:10.3389/fpsyt.2020.00431

State-Independent Microstructural White Matter Abnormalities in Major Depressive Disorder

Front Psychiatry. 2020 May 14:11:431. doi: 10.3389/fpsyt.2020.00431. eCollection 2020.

Authors

Qiangli Dong^{1

2}, Jin Liu^{1

2}, Lingli Zeng³, Yiming Fan³, Xiaowen Lu^{1

2}, Jinrong Sun^{1

2}, Liang Zhang^{1

2}, Mi Wang^{1

2}, Hua Guo⁴, Futao Zhao⁴, Danfeng Yan^{1

2}, Haolun Li^{1

2}, Weilong Guo^{1

2}, Yan Zhang^{1

2}, Bangshan Liu^{1

2}, Dewen Hu³, Lingjiang Li^{1

2}

Affiliations

¹ Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, China.
² Mental Health Institute of Central South University, China National Clinical Research Center on Mental Disorders (Xiangya), China National Technology Institute on Mental Disorders, Hunan Technology Institute of Psychiatry, Hunan Key Laboratory of Psychiatry and Mental Health, Changsha, China.
³ College of Intelligence Science and Technology, National University of Defense Technology, Changsha, China.
⁴ Department of Psychiatry, Zhumadian Psychiatric Hospital, Zhumadian, China.

Abstract

Background: Even with continuous antidepressant treatment, residual symptoms and the risk of relapse can persist in remitted major depressive disorder (MDD) patients. Hence, having a clear recognition of the persistent abnormalities of the underlying neural substrate in MDD through a longitudinal investigation is of great importance.

Methods: A total of 127 adult medication-free MDD patients with an acute depressive episode and 118 matched healthy controls (HCs) underwent diffusion tensor imaging. Over a 6-month treatment course, 62 remitted patients underwent a second scan. Remission was defined as a 24-item Hamilton Depression Rating Scale (HAMD₂₄) score ≤7 for at least two weeks. Diffusion tensor imaging was performed with a 3.0 T scanner. Differences in whole-brain fractional anisotropy (FA) between MDD patients and HCs were assessed by an independent t-test using gender, age, and education as covariates.

Results: Significant FA reductions in the left insula, left middle occipital gyrus, right thalamus, left pallidum and left precuneus were observed in current MDD (cMDD) patients compared with HCs. Moreover, significant FA reductions in the left insula were observed in remitted (rMDD) patients compared to HCs. However, no significant differences in FA values were found when comparing cMDD and rMDD patients.

Conclusions: The abnormalities in the insula showed state-independent characteristics, while the abnormalities in the middle occipital gyrus, thalamus, pallidum and precuneus seemed to be state-dependent impairments in MDD patients.

Keywords: diffusion tensor imaging; fractional anisotropy; major depressive disorder; state-independent; white matter microstructure.