A new study headed by the University of Cambridge has discovered a relationship that suggests lithium may reduce the chance of acquiring dementia.
The findings were reported in the journal ‘PLoS Medicine.’ The study included a retrospective review of nearly 30,000 patients’ health data from the Cambridgeshire and Peterborough NHS Foundation Trust. Between 2005 and 2019, the patients were all above the age of 50 and used NHS mental health treatments.
Although the overall number of patients who took lithium was modest, the analysis revealed that those who received lithium were less likely to acquire dementia than those who did not. It also stated that lithium may be used as a prophylactic therapy for dementia and that big randomised controlled trials could be conducted.
Dementia is the biggest cause of mortality in older Western populations, however there are presently no prophylactic therapies available. Dementia affects more than 55 million people globally, with Alzheimer’s disease being the most common kind.
“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 per cent,” he added.
Previous research have advocated lithium as a viable treatment for persons who have already been diagnosed with dementia or early cognitive impairment, but it is uncertain if it may postpone or even prevent the onset of dementia entirely, due to the small sample size of these studies.
Lithium is a mood stabiliser that is commonly used for 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 Chen.
Chen and his colleagues examined data from Cambridgeshire and Peterborough NHS Foundation Trust patients who sought mental health treatments between 2005 and 2019. Patients were all above the age of 50, had at least one year of follow-up appointments, and had not previously been diagnosed with moderate cognitive impairment or dementia.
548 of the 29,618 individuals in the research group had had lithium treatment, whereas the remaining 29,070 had not. Their average age was slightly under 74 years, and almost 40% of the patients were male.
In the lithium group, 53 people, or 9.7 percent, were diagnosed with dementia. In the group that did not get lithium, 3,244 people, or 11.2%, were diagnosed with dementia.
Lithium usage was related with a decreased incidence of dementia after adjusting for variables such as smoking, other drugs, and other physical and mental diseases, both for short and long-term users.
However, because the total number of patients taking lithium was limited and this was an observational research, bigger clinical studies would be required to prove lithium as a possible dementia therapy. Another drawback of the study was the small number of individuals with bipolar illness, which is generally 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 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,” he concluded.
