Correlation between cerebral small vessel disease and late-life depression: Insights from neuroimaging studies

Late-life depression (LLD) is commonly observed in elderly individuals with cerebral small vessel disease (CSVD). Structural or functional injury of brain parenchyma can affect vascular physiology and lead to CSVD. To date, accumulating evidence has indicated that advanced age and persistent hypertension may damage the regulation of cerebral blood flow (CBF) in response to hemodynamic changes. CBF abnormalities have been associated with endothelial damage followed by blood-brain barrier (BBB) disruption, and together they injure brain parenchyma. Consequently, ischemic neuroimaging markers are manifested in the form of lacunar strokes, cerebral microbleeds, enlarged perivascular spaces, subcortical infarcts, and particularly white matter hyperintensity. According to statistical analyses, CSVD-related hallmarks are associated with depression, especially in late life, as has been suggested by the well-known vascular depression hypothesis. Dysfunctional coordination, involving limbic-cortical pathways from fronto-subcortical circuits, is now drawing more attention. In the elder individuals with depression, the implicit role of numerous CSVD abnormalities have yet been sorted and elucidated exclusively. Connections between neuroimaging findings and clinical pathology are not clarified. This review summarized a possible association between CSVD and LLD to gain insights into the mechanism of LLD's development.