Desynchronized Functional Activities Between Brain White and Gray Matter in Major Depression Disorder

Area of Science:

• Neuroimaging
• Psychiatry
• Neuroscience

Background:

• Gray matter (GM) alterations are implicated in major depressive disorder (MDD) and treatment response.
• White matter (WM) connectivity's role in MDD pathophysiology remains incompletely understood.

Purpose of the Study:

• To investigate functional connectivity (FC) in WM, GM, and WM-GM in MDD patients.
• To explore the relationship between FC and antidepressant treatment outcomes.

Main Methods:

• Longitudinal study involving 129 MDD patients and 89 healthy controls (HC).
• fMRI (3.0T BOLD) and Hamilton Depression Rating Scale (HAMD) assessments at baseline and after 2 and 8 weeks of treatment.
• Statistical analyses included t-tests, chi-square tests, correlation analyses, and receiver operator curve analysis.

Main Results:

• MDD patients showed widespread decreases in WM-GM FC compared to HC.
• Significant reductions in connectivity were observed in 28 GM regions and 11 WM bundles in MDD patients.
• Baseline FC negatively correlated with HAMD scores and positively correlated with 2- and 8-week antidepressant response rates.

Conclusions:

• Decreased WM-GM functional connectivity is a characteristic of MDD.
• WM-GM FC alterations may contribute to MDD pathophysiology and influence antidepressant treatment efficacy.