Specific alterations of resting-state functional connectivity in the
triple network related to comorbid anxiety in major depressive disorder
Abstract
The brain‘s default mode network (DMN) and the executive control network
(ECN) switch engagement influenced by the ventral attention network
(VAN). Alterations in resting-state functional connectivity (RSFC)
within this so-called triple network have been demonstrated in patients
with major depressive disorder (MDD) or anxiety disorders (AD). This
study investigated alterations in the RSFC in patients with comorbid MDD
and ADs to better understand the pathophysiology of this prevalent group
of patients. Sixty-eight participants (52.9 % male, mean age 35.25
years), consisting of 25 patients with comorbid MDD and ADs (MDD+AD), 20
patients with MDD only (MDD-AD) and 23 healthy controls (HC) were
investigated clinically and with 3T resting-state fMRI. RSFC utilizing a
seed-based approach within the three networks belonging to the triple
network was compared between the groups. Compared to HC, MDD+AD showed
significantly reduced RSFC between the ECN and the VAN, the DMN and the
VAN and within the ECN. No differences could be found for the MDD group
compared to both other groups. Furthermore, symptom severity and
medication status did not affect RSFC values. The results of this study
show a distinct set of alterations of RSFC for patients with comorbid
MDD and AD compared to healthy controls. This set of dysfunctions might
be related to less adequate switching between the DMN and the ECN as
well as poorer functioning of the ECN. This might contribute to
additional difficulties engaging and utilizing consciously controlled
emotional regulation strategies.