Lithium (Low-Dose) for Cognitive Function

Research suggests that low-dose lithium may offer modest but meaningful benefits for cognitive function, particularly in the context of age-related decline and neurodegenerative conditions. A 2024 network meta-analysis of over 6,500 participants found that lithium performed comparably or superiorly to newer anti-amyloid antibody drugs on certain cognitive measures while showing better tolerability, and a large 2026 ecological study found that counties with higher naturally occurring lithium levels in drinking water had modestly lower rates of dementia diagnoses. Supporting evidence comes from a 2023 review article suggesting neuroprotective effects at low doses, a mouse study finding improved cognitive outcomes when low-dose lithium was combined with another drug after mild traumatic brain injury, and a pilot animal study showing enhanced and more durable cognitive benefits when lithium was added to an antipsychotic regimen. However, the evidence has notable limitations: a 2023 randomized controlled trial in Alzheimer's patients found no significant change in BDNF levels or cognitive function with lithium treatment, several of the supporting studies are animal models or ecological analyses that cannot establish causation at the individual level, and researchers consistently note that this field remains in early stages with more rigorous human trials needed before firm conclusions can be drawn.