Aberrant brain dynamics in major depressive disorder with suicidal ideation

Area of Science:

• Neuroscience
• Psychiatry
• Medical Imaging

Background:

• Suicidal ideation (SI) is a common symptom in major depressive disorder (MDD).
• Previous research linked MDD with SI to static brain alterations.
• Dynamic changes in brain activity patterns in MDD with SI remain largely unknown.

Purpose of the Study:

• To investigate the dynamic brain activity and functional connectivity patterns in MDD patients with suicidal ideation (MDD-SI) compared to those without (MDD-NSI) and healthy controls (HCs).
• To explore the correlation between altered dynamic brain metrics and the severity of suicidality.

Main Methods:

• Resting-state functional magnetic resonance imaging (rs-fMRI) was used in 60 MDD-SI, 58 MDD-NSI, and 58 HCs.
• The sliding-window approach calculated dynamic fractional amplitude of low-frequency fluctuation (dfALFF) for regional activity and dynamic degree centrality (dDC) for functional connectivity.
• Group comparisons and correlation analyses were performed between dynamic metrics and suicidality severity.

Main Results:

• MDD-SI exhibited decreased dfALFF in the left lingual gyrus and right middle occipital gyrus compared to MDD-NSI.
• MDD-SI showed decreased dDC in the right middle frontal gyrus relative to MDD-NSI.
• Reduced dDC in the right middle frontal gyrus significantly correlated with increased suicidality severity.

Conclusions:

• Specific alterations in brain dynamic regional activity and distant functional connectivity distinguish MDD-SI from MDD-NSI.
• Decreased temporal variability in the right middle frontal gyrus's distant connectivity is a key finding associated with SI.
• These dynamic brain patterns may indicate a neurobiological predisposition for suicidal ideation in major depressive disorder.