Abnormal Functional and Structural Connectivity of Amygdala-Prefrontal Circuit in First-Episode Adolescent Depression: A Combined fMRI and DTI Study.

Feng Wu,Zhaoyuan Tu,Huizi Li,Haiyang Geng,Jiaze Sun,Xiaowei Jiang,Yifang Zhou,Lingtao Kong

doi:10.3389/fpsyt.2019.00983

Abstract

BackgroundAbnormalities of functional and structural connectivity in the amygdala-prefrontal circuit which involved with emotion processing have been implicated in adults with major depressive disorder (MDD). Adolescent MDD may have severer dysfunction of emotion processing than adult MDD. In this study, we used resting-state functional magnetic resonance imaging (rs-fMRI) and diffusion tensor imaging (DTI) to examine the potential functional and structural connectivity abnormalities within amygdala-prefrontal circuit in first-episode medication-naïve adolescents with MDD.MethodsRs-fMRI and DTI data were acquired from 36 first-episode medication-naïve MDD adolescents and 37 healthy controls (HC). Functional connectivity between amygdala and the prefrontal cortex (PFC) and fractional anisotropy (FA) values of the uncinate fasciculus (UF) which connecting amygdala and PFC were compared between the MDD and HC groups. The correlation between the FA value of UF and the strength of the functional connectivity in the PFC showing significant differences between the two groups was identified.ResultsCompared with the HC group, decreased functional connectivity between left amygdala and left ventral PFC was detected in the adolescent MDD group. FA values were significant lower in the left UF within the adolescent MDD group compared to the HC group. There was no significant correlation between the UF and FA, and the strength of functional connectivity within the adolescent MDD group.ConclusionsFirst-episode medication-naïve adolescent MDD showed decreased functional and structural connectivity in the amygdala-prefrontal circuit. These findings suggest that both functional and structural abnormalities of the amygdala-prefrontal circuit may present in the early onset of adolescent MDD and play an important role in the neuropathophysiology of adolescent MDD.

Highlights

Major depressive disorder (MDD) is characterized by emotional dysregulation, implicating abnormalities of frontal-limbic neural circuits involved in emotional processing as the core feature
To further evaluate the relationship between functional and structural connectivity, we investigated the correlations in MDD and healthy control subjects (HC) participants separately between the Fractional anisotropy (FA) values of uncinate fasciculus (UF) and the strength of the functional connectivity in the regions showing significant differences between the two groups
With age as covariant We found significantly decreased left ventral prefrontal cortex (PFC) (VPFC, Brodmann areas (BA) 47) resting state functional connectivity (rsFC) from the left amygdala in the adolescent MDD group, compared with the HC group [peak Montreal Neurological Institute (MNI) coordinates of the left ventral prefrontal cortex (VPFC) region: x = -35, y = 21, z = -11, 45 voxels (1215mm3), T = 3.53] (Figure 1, Table 2)

Summary

Introduction

Major depressive disorder (MDD) is characterized by emotional dysregulation, implicating abnormalities of frontal-limbic neural circuits involved in emotional processing as the core feature. Convergent studies provide consistent evidence for functional and structural abnormalities in the prefrontal cortex (PFC) and amygdala, the key components of frontal-limbic neural circuits in adult MDD. Dysfunction of amygdala-prefrontal circuits has been implicated in MDD through functional magnetic resonance imaging (fMRI). Abnormalities of functional and structural connectivity in the amygdalaprefrontal circuit which involved with emotion processing have been implicated in adults with major depressive disorder (MDD). We used resting-state functional magnetic resonance imaging (rs-fMRI) and diffusion tensor imaging (DTI) to examine the potential functional and structural connectivity abnormalities within amygdala-prefrontal circuit in first-episode medication-naïve adolescents with MDD

Methods

Results

Discussion

Conclusion