Research results have emerged indicating that antidepressants prescribed for patients with dementia impair cognitive functions such as memory and thinking. Patients with dementia often experience anxiety, depression, and hallucinations, leading to the prescription of antidepressants. Therefore, medication aimed at alleviating psychological symptoms has negatively impacted the patients' conditions. However, other researchers have taken a cautious stance, noting that it is premature to conclude that antidepressants are detrimental to dementia.
A research team from Sweden's Karolinska Institute led by Professor Sara Garcia-Ptacek announced on the 25th in the international journal BMC Medicine that they confirmed the finding that selective serotonin reuptake inhibitors (SSRIs), a type of antidepressant, can accelerate cognitive decline in dementia patients through a study tracking more than 20,000 dementia patients, some of whom took SSRIs and some who did not.
Serotonin is known to ease depression and is often referred to as the 'happiness hormone.' Once secreted from brain cells, it is absorbed again and broken down, but SSRIs prevent the absorption of serotonin, instead increasing its levels. SSRIs are widely prescribed not only for depression but also for anxiety disorders and dementia patients.
The research team compared the cognitive decline trends between 11,912 patients taking antidepressants and 6,828 patients not taking them among 18,740 dementia patients in Sweden from May 1, 2007, to October 16, 2018. The average age of the patients was 78, and 64.8% of the prescribed antidepressants were SSRIs.
Evaluation of the patients using a brief mental state examination revealed that when antidepressants were taken more than once, cognitive function scores decreased by an average of 0.42 points annually. Moreover, the group taking antidepressants showed a higher risk of death from age-related diseases, including fractures, compared to other patients. The risk increased as the dosage of antidepressants increased.
Professor Garcia-Ptacek noted, 'Although antidepressants have been prescribed to dementia patients for a long time, there has not been research investigating their impact on cognitive function,' adding, 'Additional studies are necessary to understand what risks may be associated with antidepressants for dementia patients.'
However, following the release of this study, experts raised counterarguments. Richard Isaacson, a research director at the U.S. Alzheimer's Disease Research Center, refuted, 'While this study states that the cognitive function scores of patients taking antidepressants declined by 0.42 points annually, dementia patients typically decline by 1 to 3 points each year,' emphasizing, 'Ultimately, the cognitive decline among patients taking antidepressants has progressed at a significantly slower pace compared to typical dementia patients.'
Professor Isaacson expressed concern that families of patients might see the study results and think, 'If we use antidepressants, our parents' dementia will progress more quickly,' and stressed that 'antidepressants are essential for helping dementia patients avoid withdrawal.'
Professor Emma Anderson from University College London noted that 'far more research is needed to confirm the association between antidepressants and cognitive decline,' warning that 'making such claims based on limited evidence could cause significant confusion among the public, who know that antidepressants help millions of people worldwide.'
References
BMC Medicine (2025), DOI: https://doi.org/10.1186/s12916-025-03851-3