Long prescribed as a treatment for bipolar disorder, lithium is emerging as a surprising candidate in the fight against Alzheimer’s disease.
Early research in 2022 suggested that low doses of lithium could protect neurons, reduce toxic protein build up, and support cellular repair in the brain. Preliminary results indicated that lithium might help delay Alzheimer’s onset or progression, though dosing remained a critical challenge: too little risked being ineffective, too much could cause kidney and thyroid complications.
New work from Harvard University this year has strengthened the case. Analysing brain samples from 285 people, researchers found lithium levels were significantly lower in individuals with Alzheimer’s and mild cognitive impairment. They also discovered that amyloid plaques — a hallmark of Alzheimer’s pathology — contained nearly three times more lithium than surrounding tissue, suggesting the brain may both lose and trap the mineral as the disease progresses. Even more telling, amyloid plaques — the sticky protein deposits central to Alzheimer’s pathology — contained nearly three times more lithium than surrounding tissue, suggesting the brain may lose lithium in two ways: impaired uptake early in disease, and sequestration within plaques as it progresses
That work helped to reframe lithium as more than a psychiatric drug. It highlighted its potential as a neuroprotective agent — inexpensive, widely available, and worthy of closer investigation.
Mice bred to develop Alzheimer’s fared poorly on memory tests when fed a lithium-deficient diet, developing more amyloid plaques and greater brain inflammation. When given ultra-low doses of lithium orotate — around 1,000 times lower than psychiatric doses — the mice not only produced fewer plaques but also regained memory performance, without the toxicity risks of higher doses.
Together, the studies highlight lithium’s potential to slow the onset or progression of Alzheimer’s disease. While experts stress that human clinical trials remain essential, the research points to an inexpensive, widely available compound that could one day protect memory as well as mood.