The associations of depression and hypertension with brain volumes: Independent or interactive?

Area of Science:

• Neuroscience
• Psychiatry
• Cardiology

Background:

• Major depressive disorder (MDD) and hypertension independently affect brain regions involved in emotional and autonomic regulation.
• The combined effects and interactions of MDD and hypertension on brain structure remain unexamined.

Purpose of the Study:

• To investigate the unique and interactive effects of MDD and hypertension on gray and white matter brain volumes.
• To explore if brain volume in specific regions mediates the comorbidity between MDD and hypertension.

Main Methods:

• Voxel-based morphometry (VBM) was employed to analyze brain volumes in a sample of individuals with MDD and/or hypertension.
• Analyses focused on main effects of MDD and hypertension, as well as their interactions, on gray and white matter volumes.
• Whole-brain analyses and region-of-interest (ROI) analyses (hippocampus, ACC, IFG) were conducted, with results corrected for multiple comparisons.

Main Results:

• Significant interactive effects were observed in the mid-cingulate cortex (MCC), cerebellum, and anterior cingulate cortex (ACC) total ROI volume.
• MDD combined with hypertension was associated with reduced gray matter volume in the ACC and MCC.
• A trend towards larger cerebellar gray matter volume was noted in individuals with both MDD and hypertension; no white matter volume associations were found.

Conclusions:

• The coexistence of MDD and hypertension exerts unique effects on brain volumes within critical emotional and autonomic regulatory areas.
• Brain volume alterations in these interconnected regions may serve as a key mechanism underlying the comorbidity of MDD and hypertension.