Several researchers have found that lithium has some value in fighting dementia. The researcher Lars Kessing has published several studies showing that people taking clinical doses of lithium for bipolar disorder have a lower incidence of dementia in old age.
In 2011, another researcher, Oreste Vicentes Forlenza, reported that a year of low-dose lithium (typically around 300mg/day) slowed deterioration in people with mild cognitive impairment compared to placebo.
In an article published in the journal Current Alzheimer Research in 2013, researchers led by Marielza Andrade Nunes reported that very small doses of lithium (more than a thousand times lower than doses used to treat mood disorders) also improved mild cognitive impairment in people with Alzheimer’s disease.
In Nunes’ study, participants with Alzheimer’s disease were randomly assigned to receive either 300 micrograms of lithium daily or a placebo. Beginning at three months of treatment, those receiving the microdoses of lithium showed stable performance on a common Alzheimer’s evaluation tool that measures how well patients remember, recall information, and follow directions; while those taking placebo got worse.
This continued over the 15 months of the study, with the difference between the two groups intensifying over time—those taking placebo got worse, while those getting the microdoses of lithium remained stable.
There were no complaints of side effects from the microdoses of lithium, and participants showed no sign of impairment to their kidney or thyroid function (a risk with the higher doses of lithium used to treat bipolar disorder).
In 2015, Nunes and colleagues reported in the journal PLOS ONE that in a mouse model of Alzheimer’s disease, mice treated with chronic low doses of lithium in their water had less memory disruption, fewer plaques in the brain, and fewer reductions in cortex and hippocampus size compared to mice given plain water.
These studies suggest that low or micro doses of lithium may be a promising treatment for Alzheimer’s disease. Much more research is needed to determine appropriate lithium dosing for the treatment of dementia or cognition problems.