Amyloid plaques, the protein deposits that define Alzheimer's disease, bind natural lithium in brain tissue and deprive neurons of a mineral they need to function normally. Professor Bruce Yankner of Harvard Medical School spent ten years tracing this mechanism, and in a study published in Nature in August 2025 he showed that restoring lithium levels with a targeted compound reverses plaques and restores memory in a mouse model of the disease.
How Plaques Rob the Brain of Lithium
Yankner, co-director of the Paul F. Glenn Center for the Biology of Aging at Harvard Medical School, leads a team including scientists Liviu Aron, Ngian Zhen Kai and Chenxi Qiu. Their central finding: amyloid plaques bind naturally occurring lithium and strip it from brain tissue. In brain regions of Alzheimer's patients, particularly the prefrontal cortex, the team measured significantly lower lithium levels than in healthy people of the same age.
To test whether this lithium depletion contributes to the disease rather than merely accompanying it, the team induced artificial lithium deficiency in healthy mice. The animals developed Alzheimer-like changes more rapidly and showed greater memory loss than controls. The mechanism operates in both directions: amyloid plaques reduce available lithium, and lithium deficiency accelerates the formation of further plaques.
Why Lithium Orotate, Not Lithium Carbonate
The team tested sixteen different lithium compounds. Lithium carbonate, the standard psychiatric medication, was eliminated early. Delivering a therapeutically effective dose would require quantities that produce serious side effects, including tremors, weight gain and kidney damage. Lithium orotate crosses the blood-brain barrier far more efficiently and achieves the same result at one-thousandth the dose of a psychiatric formulation.
In mice with Alzheimer's pathology, lithium orotate not only prevented further plaque growth but partially reversed existing amyloid and tau deposits. Synapses, the connection points between neurons, reformed. On memory tasks requiring spatial orientation, treated animals performed similarly to healthy controls.
How Far Is the Path to a Treatment?
Around 55 million people worldwide live with Alzheimer's disease or related dementias, and the World Health Organization estimates that number will triple by 2050. Current treatments such as lecanemab and donanemab can slow disease progression in patients diagnosed early but cannot halt it and work only in a subset of patients. That lithium orotate in a mouse model partially reverses existing plaques and restores memory is an unusual result.
A standard caveat applies, and Alzheimer researchers emphasize it consistently: mice do not develop genuine Alzheimer's disease. Animal models reproduce only specific aspects of the pathology, and numerous drug candidates that performed convincingly in mice have failed in human trials. The Harvard team and independent neurologists explicitly caution that no one should take lithium orotate supplements on their own initiative before clinical trials in humans confirm safety and efficacy.
What Comes Next
A clinical trial at Massachusetts General Hospital and Brigham and Women's Hospital in Boston was scheduled to begin in spring 2026. It will first investigate whether giving lithium orotate to people with early signs of cognitive decline normalizes lithium levels in the brain and whether that correlates with measurable cognitive benefits. Yankner expects the first interim results no sooner than late 2027. The discovery that Alzheimer's may partly reflect a mineral deficiency opens a research direction that dementia science has barely explored.