Association of brain network efficiency with aging, depression, and cognition

Area of Science:

• Neuroimaging
• Graph theory
• White matter connectivity

Background:

• Graph theory measures applied to neuroimaging offer new insights into brain connectivity.
• The cognitive correlates of these network measures, especially in major depression, require further investigation.

Purpose of the Study:

• To compare four network efficiency measures from novel white matter connectivity techniques.
• To examine associations between these measures, aging, depression, and cognitive functions.

Main Methods:

• Cross-sectional study of 43 healthy controls and 40 individuals with major depressive disorder.
• Diffusion tensor imaging-derived structural connectivity matrices and the Brain Connectivity Toolbox were used.
• Trail Making Test and Object Alternation task assessed information processing speed and decision-making.

Main Results:

• All four network efficiency measures showed negative correlations with age.
• In the depressed group, normalized global efficiency negatively correlated with depression severity.
• Increased global efficiency was linked to poorer performance on the Object Alternation task.

Conclusions:

• Network efficiency measures may reflect distinct aspects of brain network organization.
• These aspects vary depending on the population and behavioral context studied.