Abnormalities of intrinsic brain activity in late-life depression: a meta-analysis of resting-state functional imaging studies

Neuroimaging studies using a variety of techniques have demonstrated abnormal patterns of spontaneous brain activity in patients with late-life depression (LLD). However, the findings are variable and often inconsistent, hindering understanding of underlying neuropathology. We conducted a meta-analysis of whole-brain resting-state functional neuroimaging studies in LLD compared to healthy controls (HC), using anisotropic effect-size seed-based d mapping, to identify the most consistent brain activity alterations and their relation to clinical features. After systematic literature search, we included 13 studies reporting resting-state functional activity in a total of 476 LLD patients compared with 394 HC. We found higher activity in LLD vs HC in the left fusiform gyrus (FG), right parahippocampal gyrus (PHG) and right middle frontal gyrus (MFG), and lower brain activity in the left supplementary motor area (SMA), left superior frontal gyrus (SFG) and left postcentral gyrus (PoCG). In the subgroup meta-analysis of studies with a single functional index, LLD showed higher regional homogeneity (ReHo) in the left FG and right PHG, and also higher amplitude of low frequency fluctuations and/or fractional amplitude of low frequency fluctuations (ALFF/fALFF) in the left FG and lower activity in the left SFG. In the subgroup meta-analysis of studies using corrected p values, LLD vs HC showed similar patterns, with higher activity in the left FG, right PHG, and right MFG, and lower activity in the left SFG, left superior occipital gyrus (SOG), left PoCG, and left SMA. This study advances understanding of brain resting-state functional imaging features underlying LLD. These findings may have practical implications in the clinical diagnosis of and intervention for LLD.