Antidepressants are commonly prescribed for dementia patients, but new research suggests they might be doing more harm than good.

A study of nearly 19,000 individuals found that those taking these medications experienced a faster cognitive decline than those who didn’t. Not all antidepressants had the same effect, suggesting that careful selection could mitigate some risks.

Antidepressants Linked to Faster Cognitive Decline

Antidepressants are commonly prescribed to help manage symptoms like anxiety, depression, aggression, and sleep disturbances in people with dementia.

However, a new observational study using data from the Swedish Dementia Registry (SveDem) suggests that dementia patients taking antidepressants may experience faster cognitive decline than those who do not.

A Large-Scale Study with Surprising Results

The study analyzed data from 18,740 dementia patients, with about 23 percent receiving antidepressant treatment. Over the course of the study, 11,912 antidepressant prescriptions were recorded, with selective serotonin reuptake inhibitors (SSRIs) making up 65 percent of them.

“Depressive symptoms can both worsen cognitive decline and impair quality of life, so it is important to treat them. Our results can help doctors and other healthcare professionals choose antidepressants that are better adapted for patients with dementia,” says Sara Garcia Ptacek, researcher at the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, and the study’s last author.

Selective serotonin reuptake inhibitors (SSRIs) are a class of antidepressants commonly used to treat depression, anxiety disorders, and other mental health conditions. They work by increasing serotonin levels in the brain, which helps regulate mood.

Common SSRIs:

• Fluoxetine (Prozac)
• Sertraline (Zoloft)
• Escitalopram (Lexapro)
• Citalopram (Celexa)
• Paroxetine (Paxil)
• Fluvoxamine (Luvox)

Researchers from Karolinska Institutet and Sahlgrenska University Hospital in Gothenburg tracked the cognitive changes of dementia patients over time. They compared those taking antidepressants with those who were not, as well as examining the effects of different types of antidepressants.

While it remains unclear whether the cognitive decline is caused by the medication itself or the underlying depressive symptoms, the study found a clear association between antidepressant use and faster cognitive deterioration.

Differences Between Antidepressants Matter

The study also points to differences between different drugs. The SSRI escitalopram was associated with the fastest cognitive decline, followed by the SSRIs citalopram and sertraline.

Mirtazapine, which has a different mechanism of action, had less negative cognitive impact than escitalopram.

The researchers now want to investigate whether certain patient groups, such as people with specific dementia types or biomarkers, respond better or worse to different antidepressants.

“The goal is to find these subgroups to create more individualised care,” says Sara Garcia Ptacek.

Reference: “Antidepressant use and cognitive decline in patients with dementia: a national cohort study” by Minjia Mo, Tamar Abzhandadze, Minh Tuan Hoang, Simona Sacuiu, Pol Grau Jurado, Joana B. Pereira, Luana Naia, Julianna Kele, Silvia Maioli, Hong Xu, Maria Eriksdotter and Sara Garcia-Ptacek, 25 February 2025, BMC Medicine.
DOI: 10.1186/s12916-025-03851-3

The study has been funded by the Swedish Research Council, Region Stockholm, the Swedish Dementia Research Foundation, the Alzheimer’s Foundation and New Innovative Roads Call – a private initiative from the Leif Lundblad family and others. The researchers report no conflicts of interest.