Table 3.

Microglial changes.

Type of disorder	In vivo imaging data	Postmortem molecular data	Postmortem cellular data
Major depressive disorder	Increased TSPO density in the PFC, ACC and insula detected by PET scan (Setiawan et al., 2015) TSPO availability was higher in the ACC and insula of patients with suicidal thoughts compared to patients without such intention (Holmes et al., 2018)	Up-regulated gene expression of Iba-1 and MCP-1 in suicides (Torres-Platas et al., 2014) Elevated cytokines (TNF-α, IL-1β, IL-6) and Toll-like receptors in the PFC of suicide victims (Pandey, 2017) Reduced expression of genes associated with microglia and glial cell functions in the DLPFC (Pantazatos et al., 2017)	HLA-DR-immunopositive activated microglia in the hippocampal CA1 area (Bayer et al., 1999) Significant microgliosis in the ACC, DLPFC and MD thalamus of suicide patients (Steiner et al., 2008) Significantly increased density of QUIN-positive cells in the sACC and aMCC (Steiner et al., 2008) Increased ratio of primed Iba-1-positive microglia in the white matter of the dorsal ACC in depressed suicides (Torres-Platas et al., 2014) Increased proportion of blood vessels surrounded by macrophages (Torres-Platas et al., 2014) Increased density of Iba-1-positive cells in contact with blood vessels in the dorsal PFC white matter of suicide victims (Schnieder et al., 2014)
Bipolar disorder	Elevated TSPO binding in the right hippocampus (Haarman et al., 2014)

Abbreviations: ACC, anterior cingulate cortex; aMCC, anterior midcingulate cortex; DLPFC, dorsolateral prefrontal cortex; HLA-DR, the major histocompatibility complex II protein; Iba-1, ionized calcium binding adaptor molecule 1; MCP-1, monocyte chemoattractant protein-1; MD, mediodorsal; PET, Positron-Emission Tomography; PFC, prefrontal cortex; QUIN, quinolinic acid; sACC, subgenual anterior cingulate cortex; TSPO, translocator protein-18 kDa.