You may have caught wind of a recent study out of Harvard looking at the connection between lithium and Alzheimer’s disease.
You’ve probably heard the word lithium before. Maybe you think of batteries, or the treatment of bipolar disorder. But researchers at Harvard are looking at lithium levels in the brain, and at lithium’s potential as a treatment for Alzheimer’s disease.
Here’s what they found, and what’s important to remember before getting your hopes up.
What Is Lithium?
Lithium is a natural element that’s been used to treat mental health conditions since the late 1940s. Doctors still use it today to help people with certain mood disorders, such as bipolar disorder.
But researchers have discovered it may help the brain with more than just mood. It may help by:
- helping brain cells talk to one another
- helping brain cells stay alive longer
- helping the brain make a special protein called BDNF, which helps the brain grow and heal
In a study of rats, chronic lithium increased levels of that same protein in both the hippocampus and the cortex.
That’s important, because Alzheimer’s disease makes those same brain connections break down.
What the Harvard Study Found
The Harvard researchers looked at two things. They measured the level of lithium in the brains of people with and without Alzheimer’s disease. And they looked at what happened to mice when lithium levels were changed. (Harvard Medical School; the full paper is Lithium deficiency and the onset of Alzheimer’s disease, in Nature.)
In people: those who had memory problems had less lithium in their brains at the time of their death.
In mice: the mice with low levels of lithium had more plaques and more tangles in their brains. Those are the changes we’ve heard a lot about in Alzheimer’s disease, and they’re connected with memory loss.
Then came the really interesting part. The scientists gave a special kind of lithium, at a very small dose, to the mice with Alzheimer’s-like symptoms.
The mice did better. Their memory improved. Their brains had fewer signs of the disease, with fewer plaques and tangles.
So this study suggests lithium might not just help the brain. It might be essential to keeping the brain running well. It also suggests that low levels of lithium in the brain may be part of how Alzheimer’s disease begins.
What Caregivers Should Know Before Getting Excited
This is exciting news, and something to keep watching. But for now, here are some important things to remember.
- Mouse evidence doesn’t equal human cures. The Harvard study is powerful, but it’s in mice and human tissue samples. It’s not yet large human clinical studies.
- The lithium trials so far are small and short. Many trials of lithium for Alzheimer’s or mild cognitive impairment last weeks to months and involve a small number of people. What we’d like to see is bigger groups of people, studied for longer, to see how long the effects last.
- Lithium is hard to dose. It has a very narrow therapeutic window, which means it’s hard to find a dose that works, even the way we use it today.
- It can be hard on older adults. Even moderate levels can stress the kidneys, the thyroid and fluid balance. There are side effects we have to be cautious of.
- How well it works will depend on how far the dementia has progressed. That’s true of many of the treatments we have.
- Many people drop out of lithium trials. It can be difficult to tolerate.
Never Try Lithium on Your Own
Do not try any medications on your own, including lithium. It must be prescribed, and it must be carefully monitored by a doctor, even when it’s used for mental health.
Nothing in this post is a treatment recommendation. Please keep working with your loved one’s healthcare provider.
What’s Next for Lithium and Alzheimer’s Research?
Scientists are now planning bigger studies to see whether lithium really does help treat Alzheimer’s disease, and how to use it in the safest way possible.
If you want to know how those bigger studies work and why they take so long, I explain it in are we actually making progress in dementia research?
For now, the best thing you can do is stay informed, ask questions, and talk to your loved one’s doctor before trying anything new.
But this research does give us hope. It’s one more piece of the puzzle in fighting Alzheimer’s disease.
When a new headline lands every week, it can be hard to know which ones matter for the person you care for. Inside the Care Collective, we talk through what research like this does and doesn’t change, and how to care for your loved one, and yourself, in the meantime. You can learn more here.
Sources & References
Harvard Medical School, “Could lithium explain and treat Alzheimer’s disease?”
Aron L, et al. Lithium deficiency and the onset of Alzheimer’s disease. Nature (2025)
