Lithium Deficiency: A Silent Trigger in Alzheimer’s Disease

One of the key challenges in Alzheimer’s research is identifying the very first events that set the disease in motion, long before memory loss or other symptoms become clear. A recent Nature study points towards lithium, a trace element usually discussed in psychiatry, as a potential early factor in brain ageing and vulnerability. Analyses of human brain tissue showed that lithium levels are markedly reduced in the prefrontal cortex of people with mild cognitive impairment and Alzheimer’s disease, while levels in the cerebellum remain comparatively stable. Crucially, amyloid plaques were found to bind lithium directly, reducing its local availability to neurons and glial cells.

This depletion had widespread consequences. In both human tissue and mouse models, lithium loss was associated with accelerated amyloid accumulation, abnormal phosphorylation of tau, activation of microglia, synaptic degeneration, myelin breakdown and measurable cognitive decline. Transcriptomic analysis showed that excitatory neurons downregulated genes linked with synaptic transmission, oligodendrocytes displayed reduced expression of myelin-related genes, and microglia activated inflammatory pathways. These changes strongly overlapped with the transcriptional patterns found in human Alzheimer’s brains, suggesting that lithium deficiency is not a downstream effect of pathology but an early driver of disease processes.

Much of this effect appears to involve dysregulation of glycogen synthase kinase-3β (GSK3β), an enzyme that lithium normally inhibits and that is closely linked with tau phosphorylation and microglial reactivity. With lithium sequestered by amyloid, GSK3β activity is left unchecked, creating a molecular bridge between ionic imbalance, synaptic instability and neuroinflammation.

The therapeutic findings are particularly interesting. Lithium carbonate, the conventional clinical salt, binds strongly to amyloid and was therefore less effective. Lithium orotate, which binds less tightly, retained bioavailability and was able to prevent and even reverse pathological changes in mice. It preserved synapses, maintained myelin, dampened inflammatory responses and supported memory. In healthy ageing mice, lithium orotate also sustained synaptic density and cognitive performance, pointing to a wider role for lithium in resilience during ageing as well as in disease.

These findings connect with other recent work that has explored how apparently minor molecular perturbations can alter the dynamics of the whole brain. A study published in Nature Computational Science used a multiscale modelling framework to examine how receptor-level changes caused by anaesthetics spread through circuits and networks to produce unconscious states. Although the focus there was on pharmacology rather than ageing, the principle is similar. Both lines of research show that small molecular events can reverberate across multiple levels of organisation, reshaping network behaviour and cognition.

For me, the convergence of these studies points towards a future in which neuroscience is increasingly integrative. Lithium deficiency may represent a silent but decisive trigger of Alzheimer’s disease, while computational models offer the means to explore how such molecular changes scale up to alter network activity and behaviour. Understanding how ions, receptors, circuits and cognition are connected in this way will be essential if we are to develop interventions that preserve resilience and delay the onset of disease.

References

1. Aron L, Ngian ZK, Qiu C, Choi J, Liang M, Drake DM, et al. Lithium deficiency and the onset of Alzheimer’s disease. Nature. 2025. doi: 10.1038/s41586-025-09335-x
2. Sacha M, Tesler F, Cofré R, Destexhe A. A computational approach to evaluate how molecular mechanisms impact large-scale brain activity. Nat Comput Sci. 2025;5:405-417. doi: 10.1038/s43588-025-00796-8

How to cite this post

Olegario RL. Lithium deficiency: a silent trigger in Alzheimer’s disease [Internet]. Brasília (BR): Raphael L. Olegario; 2025 Aug 24. Available from: https://rlolegario.com/2025/08/24/lithium-deficiency-a-silent-trigger-in-alzheimers-disease/