Lithium Shows Promise in Treating Alzheimer's

Results of testing in mice suggests it may protect against memory loss

Kristen Fischer,

AARP

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Published August 07, 2025

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Lithium has been around since the 1800s and is commonly used to treat bipolar disorder. It’s also a metal that naturally occurs in our brains. Yet, the idea of using it to prevent or reverse Alzheimer’s disease is gaining traction, thanks in part to a report published Aug. 6 in Nature.

When researchers evaluated human brain tissue and experimented with mice, they found that declining lithium levels were linked to memory loss, says Bruce Yankner, M.D., a geneticist at Harvard Medical School. Lithium deficiency was also associated with the buildup of amyloid plaques and tau tangles — hallmarks of Alzheimer’s disease.

Then Yankner’s team gave a particular form of lithium to mice with low levels of it and saw their memory problems reverse.

Though two antiamyloid drugs are available for people with early-stage Alzheimer’s because they may slow down damage to the brain, they don’t stop it, Yankner says. Today, more than 7 million Americans live with Alzheimer’s disease.

“There’s no drug that stops the progression or restores function,” he says, adding that his research offers a “glimmer of hope.” He’s hoping to see further research in people soon.

The lowdown on lithium

Lithium was used as a health tonic in the 1800s and was an early treatment for gout. Lithium carbonate has been the gold standard mood stabilizer for people with bipolar disorder since the 1970s. It’s been studied for cognitive problems, with mixed results.

Yankner’s human data came from an existing trial that evaluated participants who were either cognitively normal, had mild cognitive impairment (MCI) or had Alzheimer’s disease. The participants had agreed to regular testing and consented to let researchers examine their brain tissue after they died.

The researchers looked at levels of 27 metals in the brain tissue and blood. Of all the metals, lithium was the only one with low levels in the prefrontal cortex of people with MCI and Alzheimer’s disease — an area of the brain important for reasoning, planning and language.

Along with those who had Alzheimer’s disease, people with MCI — early on, even before amyloid began to form the tell-tale plaques — had lower lithium uptake, which could be due to genetic and environmental factors, Yankner says. People also may have less lithium because amyloid plaques sequester the metal in the brain.

Amyloid plaques trap lithium

Yankner’s team tested mice by severely reducing lithium in their diets. It's found in some foods and in water that flows through lithium-rich rock. The mice with less lithium had worse memory.

When they took mice that were engineered to have genes that gave them Alzheimer’s symptoms and gave them a low lithium diet, “the pathology dramatically increased,” Yankner explains. The mice were also less able to clear amyloid plaques, he says.

As amyloid plaques start to accumulate in the brain, they trap lithium as the disease progresses, Yankner explains.

So then his team tested two types of lithium in those mice and learned that the type of lithium mattered.

Lithium carbonate, used for bipolar disorder, got snared by the plaques. Lithium orotate was less likely to get grabbed, and it restored the memory of the mice.

More work needed in humans

Results in mice can be encouraging, but scientists need to do more studies on humans, says Manisha Parulekar, M.D., codirector of the Center for Memory Loss and Brain Health at the Hackensack Meridian Neuroscience Institute at Hackensack University Medical Center, who wasn’t involved with the study but reviewed the report. Any treatments must be shown to be effective and safe in large studies of people before they can be recommended.

Lithium orotate is available on the market as a supplement, but lithium can be toxic to humans at certain levels, so no one should take it without a doctor’s care, Parulekar says. Patients taking lithium for bipolar disorder should have their blood levels checked regularly, she adds.

Because memory was reversed in mice but has not been proved to reverse in humans, Yankner says people should not take lithium supplements. “You can never be sure what’s in them,” Yankner says, noting that they’re not regulated by the Food and Drug Administration.

“We need to wait for the clinical trials to really know what is the best dose for a person and to be assured that there won’t be toxicity,” Yankner adds.

The big takeaway from the study was confirming the effects of lithium depletion in the brain, seeing how it affected plaques and seeing that lithium orotate has the potential to reverse damage, Parulekar says. “I think that’s the reason why this is getting so much buzz,” she adds.

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Kristen Fischer is a contributing writer at AARP based at the Jersey Shore. She has also written for Health, WebMD, and McKnights and is the author of Zoo Zen: A Yoga Story for Kids.