Many of the mechanisms identified by the aforementioned organoid studies are common to depression and AD, including decreased serotonergic innervation, neuroinflammation, and disruptions in crucial signaling pathways, including BDNF (Mendes-Silva et al., 2016; Linnemann and Lang, 2020; Bajaj and Mahesh, 2024). Here, BDNF is linked to depressive symptom measurement.