Concerning the neurobiological link between stress and depression, several studies have highlighted the role of microglia and macrophage (M/Ms) activation [18, 26–32] mediated by purinergic signalling via the membrane-bound adenosine triphosphate (ATP) receptor P2X7 (P2X7R) [33–40]. This evidence concerns the gene P2RX7 and major depressive disorder.