A new study has raised concerns over the use of antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs), in dementia patients, suggesting a possible link to accelerated cognitive decline. The study, conducted by researchers at the Karolinska Institute in Sweden, found that dementia patients taking SSRIs experienced a more rapid deterioration in brain function compared to those who were not on the medication.
According to NHS data, an estimated 5.4 million patients in England are currently prescribed SSRIs, making them the most commonly used antidepressant in the country. These medications are often prescribed to dementia patients to help manage mood and behavioral changes associated with the condition.
Dementia is a syndrome characterised by a decline in cognitive function such as memory, thinking, orientation, comprehension, calculation, learning capacity, language, and judgment—beyond what might be expected from normal aging. This deterioration in cognitive abilities is often accompanied by changes in emotional control, social behavior, or motivation.
The World Health Organisation (WHO) states that dementia results from a variety of diseases and injuries that primarily or secondarily affect the brain, with Alzheimer’s disease being the most common form, contributing to 60–70 per cent of cases. It’s important to note that while age is the strongest known risk factor, dementia is not an inevitable consequence of aging. The condition significantly impacts individuals, their families, and caregivers, leading to increased dependency and the need for care as it progresses.
In Nigeria, prevalence varies across studies. Researchers from the University of Ibadan, Yusuf Baiyewu and colleagues, in their study on Aging and Mental Health, reported an overall dementia prevalence of 6.4 percent, with higher rates observed in women. However, a separate study by Hendrie, Ogunniyi, Hall, and colleagues in Ibadan found a lower prevalence rate of 2.3 per cent in 2001 published in Alzheimer’s & Dementia journal. These variations may result from differences in study methodologies, population demographics, and regional factors.
The research analysed data from nearly 19,000 dementia patients with an average age of 78, following them over a four-year period. Among the participants, about 20 percent were on antidepressants, with the majority (65 percent) taking SSRIs. The study measured cognitive function using memory tests that assessed the ability to recall information such as dates, years, and word lists.
Findings indicated that patients taking SSRIs experienced a decline of 0.39 additional points per year on a 30-point cognitive scale, while those on higher doses saw a more pronounced decline of 0.42 points per year. The authors, however, noted that while the difference was measurable, the clinical significance remains uncertain.
Further analysis revealed that patients on antidepressants had a seven percent higher risk of death and an 18 percent increased likelihood of fractures. Those on higher doses of SSRIs were found to be 35 percent more likely to develop severe dementia, with an 18 percent higher chance of death and a 25 percent increased risk of bone fractures. Despite these findings, researchers emphasised that the study could not establish a direct causal relationship between the drugs and these adverse outcomes. They suggested that the observed decline could be attributed to the underlying depression rather than the medication itself.
An additional aspect of the study showed that patients with frontotemporal dementia, a rarer form of the disease that affects younger individuals, exhibited a slower progression of symptoms when treated with antidepressants. This highlights the complexity of antidepressant effects on different forms of dementia.
Commenting on the findings, Professor Tara Spires-Jones, president of the British Neuroscience Association, acknowledged the study’s robustness but emphasised the need for further research. She noted that patients requiring antidepressants might have had more aggressive forms of dementia, potentially influencing the study’s outcomes.
Similarly, Richard Oakley, associate director for research and innovation at the Alzheimer’s Society, stated that while the study suggested a link between antidepressant use and cognitive decline, it did not rule out depression itself as a contributing factor. He stressed the need for more research to clarify the effects of antidepressants on dementia progression.
Dr Prasad Nishtala, a life sciences expert at the University of Bath, also underscored the study’s limitations, particularly the lack of mechanistic explanation for the observed cognitive decline. He called for further investigations using broader real-world data sources to validate the findings.
){kind=link}