Lithium’s therapeutic window: Although trace or low-dose lithium supplementation appears safe and potentially protective, long-term pharmacological doses are associated with adverse effects, including renal impairment, thyroid dysfunction, and tremor (Malhi et al., 2013); The recent Nature study (Aron et al., 2025), which demonstrated that lithium deficiency exacerbates amyloid and tau pathology while supplementation prevented decline in mouse models of AD, provides strong support for the biological plausibility of our model. This evidence concerns the gene MAPT and Alzheimer disease.