Understanding structural-functional connectivity coupling in patients with major depressive disorder: A white matter...

Area of Science:

• Neuroscience
• Neuroimaging
• Psychiatry

Background:

• Major Depressive Disorder (MDD) is a complex mental health condition with significant impact on individuals and healthcare systems.
• Understanding the underlying neural mechanisms of MDD is crucial for developing effective treatments.
• White Matter (WM) tracts, essential for brain communication, are increasingly implicated in psychiatric disorders.

Purpose of the Study:

• To investigate the relationship between structural connectivity (SC) and functional connectivity (FC) coupling in WM tracts of individuals with MDD.
• To identify specific WM tracts exhibiting altered SC-FC coupling in MDD patients compared to healthy controls.
• To explore the association between SC-FC coupling alterations and clinical symptoms, including suicidal ideation and attempts.

Main Methods:

• Recruited 178 MDD patients and 173 healthy controls (HCs).
• Assessed SC-FC coupling using Euclidean distance in various WM tracts.
• Conducted primary analyses on MDD vs. HCs, and secondary analyses on MDD subgroups (suicidal ideation, attempts, non-suicidal).

Main Results:

• MDD patients showed increased SC-FC coupling in the middle cerebellar peduncle and bilateral corticospinal tract compared to HCs.
• Positive correlation found between right cerebral peduncle coupling and anxiety scores; negative correlation between right cingulum (hippocampus) coupling and suicide risk scores.
• Specific alterations observed in MDD subgroups: increased coupling in left anterior limb of internal capsule and left corticospinal tract in those with suicidal ideation; decreased coupling in right posterior limb of internal capsule in those with a history of suicidal attempts.

Conclusions:

• Significant variations in SC-FC coupling within WM tracts characterize MDD and its distinct subgroups.
• These findings underscore the critical role of WM network integrity in the pathophysiology of major depressive disorder.
• SC-FC coupling alterations may serve as potential biomarkers for MDD and its clinical manifestations.