There is an element sitting in your brain right now, and nobody has established how much you are supposed to have. It may shape how you think, how you act, and whether your mind holds up as you age. Last year a Harvard lab placed it near the center of Alzheimer's, arguing that running short of it may be one of the first things that goes wrong in the diease. It is already sold as the next longevity compound, the thing that finally protects the aging brain, and the people selling it have a real paper behind them. This investigation takes that case apart study by study to find out how much of it holds. The question sounds simple. The answer, as always, is not.

00:00 – Intro: Lithium and the Brain
01:57 – Lithium's Origin as a Bipolar Drug
04:55 – The Brain Growth Claim
10:10 – Where the Evidence Breaks Down
12:12 – The Harvard Brain Study
15:36 – Should You Take Lithium?
18:04 – New Trial Starting This Fall

IN THIS INVESTIGATION

-How the same element was written up as a poison and a cure in a single year, and why it was already inside every patient before anyone prescribed it.

-What happened to dementia rates across whole countries sorted by nothing but the rock their water ran through.

-Why the strongest pillars of the anti-aging case fell apart the moment someone tested them a second way.

-The measurement hiding inside every trial ever run on it, and the one small study that took it.

-What a Harvard lab found in 2025 when it finally pointed a sensitive enough instrument at an ordinary brain.


REFERENCES

Aron L, Ngian ZK, Qiu C, et al. Lithium deficiency and the onset of Alzheimer's disease. Nature, 2025. PMID 40770094

Gildengers AG, et al. Low-dose lithium for mild cognitive impairment: a pilot randomized clinical trial. JAMA Neurol, 2026. PMID 41770546

Hampel H, et al. Lithium trial in Alzheimer's disease: a randomized, single-blind, placebo-controlled, multicenter 10-week study. J Clin Psychiatry, 2009. PMID 19573486

Kessing LV, et al. Association of lithium in drinking water with the incidence of dementia. JAMA Psychiatry, 2017. PMID 28832877

Knudsen NN, et al. Lithium in drinking water and incidence of suicide: a nationwide individual-level cohort study with 22 years of follow-up. Int J Environ Res Public Health, 2017. PMID 28604590

Schrauzer GN, Shrestha KP. Lithium in drinking water and the incidences of crimes, suicides, and arrests related to drug addictions. Biol Trace Elem Res, 1990. PMID 1699579

Zarse K, et al. Low-dose lithium uptake promotes longevity in humans and metazoans. Eur J Nutr, 2011. PMID 21301855

Hajek T, et al. Smaller hippocampal volumes in patients with bipolar disorder are masked by exposure to lithium: a meta-analysis. J Psychiatry Neurosci, 2012. PMID 22498078

Moore GJ, et al. Lithium-induced increase in human brain grey matter. Lancet, 2000. PMID 11072948

Cousins DA, et al. Lithium, gray matter, and magnetic resonance imaging signal. Biol Psychiatry, 2013. PMID 23158114

Mutz J, et al. The duration of lithium use and biological ageing: telomere length, frailty, metabolomic age and all-cause mortality. GeroScience, 2024. PMID 38539016

Schrauzer GN. Lithium: occurrence, dietary intakes, nutritional essentiality. J Am Coll Nutr, 2002. PMID 11838882

Duthie A, et al. Recruitment, retainment, and biomarkers of response: a pilot trial of lithium in humans with mild cognitive impairment. Front Mol Neurosci, 2019.

NOTE: This video is educational content. It is not medical advice.