Lithium treatment helps slow the progression of memory loss, according to new research, published in the British Journal of Psychiatry. The finding raises the possibility that lithium could one day be used to prevent Alzheimer’s disease.

Researchers from the University of Sao Paulo, Brazil, carried out a small-scale study with 41 people. All the participants were over the age of 60 and had been diagnosed with mild cognitive impairment. A total of 21 of the patients took low-doses of lithium every day for a year. The other 20 participants took a placebo or ‘dummy’ pill. All participants underwent tests of their memory and attention. They also gave a sample of their cerebrospinal fluid, which was tested for phospho-tau concentrations – a biomarker for Alzheimer’s disease.

After 12 months, the researchers found that all the participants experienced a decline in their memory and cognitive functioning. However, the decline was significantly smaller in the group treated with lithium than in the placebo group. Lithium treatment was also associated with a significant decrease in concentrations of phospho-tau in people’s cerebrospinal fluid.

Lithium treatment was not associated with any major side effects. People in both the lithium and placebo groups reported a similar number of side-effects, most of which were mild and only lasted for a short period.

Dr Orestes Forlenza, who led the research, said: “We found that lithium treatment reduced people’s cognitive decline. The people who received lithium treatment for a year performed better on the memory and attention tasks than those who had taken the placebo.

He added: “This study supports the idea that giving lithium to a person who is at risk of Alzheimer’s disease may have a protective effect, and slow down the progression of memory loss to dementia. Although our study has a relatively small sample size, we believe our results are promising and point to a need for further trials with larger numbers of participants.”

Professor Allan Young, a psychiatrist from Imperial College London, has welcomed the research. Writing in an editorial in the same issue of the British Journal of Psychiatry, Professor Young said: “Clearly this trial is encouraging and the effects of lithium on cognition and Alzheimer’s disease biomarkers are very suggestive of likely benefit. This trial adds to the increasing evidence that lithium may have beneficial effects on the brain and begs to be replicated in further randomised trials.”

In his editorial, Professor Allan has called on government and charitable organisations to take the lead in funding these trials. Professor Allan said: “The pharmaceutical industry is clearly very much focused on developing treatments for dementia...If such treatments were to be given to large numbers of at-risk individuals for prolonged periods of time, the commercial rewards to those owning the patents for such treatments are likely to be very considerable.

He added: “Lithium, of course, is under no patent and will not attract industry funds for further development as a treatment except perhaps as a comparator to commercial compounds or possibly in combination with another agent. The onus is therefore on governmental and charitable funding agencies. Such trials will not be cheap but, were they to prove positive, the possible benefits in health to our ever-ageing population would be beyond any such price.”