Lithium, a cheap medication long prescribed on the NHS to treat bipolar disorder and some forms of depression, may also help fight dementia, according to researchers.
Dementia affects 982,000 people in the UK, and there is currently no cure or preventative treatment.
Previous research has linked lithium deficiency to cognitive impairment. A study published in the journal Nature found lower levels of lithium in the brains of people with Alzheimer's disease.
In animal models, lithium deficiency has been shown to accelerate cognitive decline and the build-up of plaque in the brain, both of which are associated with Alzheimer's. In mice genetically engineered to develop Alzheimer's, low-dose lithium treatment improved memory performance and reduced signs of brain damage.
Researchers believe lithium may help protect brain cells involved in memory and thinking, and preserve connections between regions of the brain.
The findings were outlined in a perspective article published in the journal Translational Psychiatry, in which researchers argued that low-dose lithium warrants further investigation as a potential treatment for people with early Alzheimer's disease.
Expert reaction
Dr Richard Oakley, associate director of research and innovation at Alzheimer's Society, said the study adds to a growing discussion about the potential role of lithium in Alzheimer's, but stressed it does not show that lithium can prevent or treat dementia.
He said some research has suggested that people with Alzheimer's have lower levels of lithium in their brains, but that clinical trials in people with early Alzheimer's disease have so far been small, with no clear evidence of an impact.
Oakley said there is no single approach that will tackle dementia and that all promising avenues should continue to be explored. He said the only way to know which potential treatments can make a meaningful difference to people's lives is through more research.
