A University of Cambridge study appears to show that older adults who received lithium were less likely to develop dementia. The findings, which appear in the journal PLOS Medicine, are in agreement with other recent studies and could pave the way for larger investigations.
Dementia, the most common form of which is Alzheimer’s, currently represents the leading cause of death in elderly Western populations, but there are no preventative treatments available.
“The number of people with dementia continues to grow, which puts huge pressure on healthcare systems,” said Dr Shanquan Chen from Cambridge’s Department of Psychiatry, the paper’s first author. “It’s been estimated that delaying the onset of dementia by just five years could reduce its prevalence and economic impact by as much as 40 percent.”
In previous studies have proposed, lithium was proposed as a possible treatment for those with a dementia diagnosis or early cognitive impairment, but it is unclear whether it can delay or even prevent the development of dementia altogether, as these studies were limited in size.
Lithium is a mood stabiliser usually prescribed for conditions such as bipolar affective disorder and depression. “Bipolar disorder and depression are considered to put people at increased risk of dementia, so we had to make sure to account for this in our analysis,” said Dr Chen.
The researchers analysed data from 29 618 NHS patients who accessed mental health services between 2005 and 2019. Patients were all over 50 years of age, with a mean age just under 74, had received at least a one-year follow-up appointment, and had not been previously diagnosed with either mild cognitive impairment or dementia.
Of these patients, 548 had been treated with lithium and 29 070 had not. For the group that had received lithium, 53, or 9.7%, were diagnosed with dementia. For the group that had not received lithium, 3,244, or 11.2%, were diagnosed with dementia.
After controlling for factors such as smoking, other medications, and other physical and mental illnesses, lithium use was associated with a lower risk of dementia, both for short and long-term users. However, since the overall number of patients receiving lithium was small and this was an observational study, larger clinical trials would be needed to establish lithium as a potential treatment for dementia.
Another limitation of the study was the number of patients who had been diagnosed with bipolar disorder, which is normally associated with an increased risk of dementia. “We expected to find that patients with bipolar disorder were more likely to develop dementia, since that is the most common reason to be prescribed lithium, but our analysis suggested the opposite,” said Dr Chen. “It’s far too early to say for sure, but it’s possible that lithium might reduce the risk of dementia in people with bipolar disorder.”
Additional research is now needed to see if lithium really does have a benefit in these conditions.
Source: University of Cambridge
