P2RY12 and depressive disorder: Of note, although we did not observe difference in the homeostatic microglial marker P2RY12, a previous study reported an increase of this marker in depression in those without dementia (Böttcher et al., 2020) and a mouse model of postpartum depression suggested that decreased hippocampal expression of P2RY12 is associated with depressive symptoms (Kim et al., 2023).