Cross-sectional neuroimaging and postmortem studies have reported associations between depressive symptoms and elevated cerebral tau burden (Gatchel et al., 2017; Babulal et al., 2020; Gonzales et al., 2021; Moriguchi et al., 2021; Tommasi et al., 2021), suggesting a potential contribution of depression to early tau pathology. This evidence concerns the gene MAPT and major depressive disorder.