March 5, 2025
Some commonly prescribed antidepressants may speed cognitive decline in people with Alzheimer’s disease, new findings suggest. But more research is needed to confirm the findings, and experts caution that anyone with dementia who is taking the drugs should not stop taking them without talking to a doctor first.
Doctors commonly prescribe antidepressants to people with Alzheimer’s disease and other forms of dementia. The drugs can help to relieve problems like anxiety, depression, aggressive behaviors and poor sleep.
“Depressive symptoms can both worsen cognitive decline and impair quality of life, so it is important to treat them,” said study author Dr. Sara Garcia Ptacek of the Karolinska Institute in Sweden. “Our results can help doctors and other health care professionals choose antidepressants that are better adapted for patients with dementia.”
For the study, researchers looked at 18,740 men and women with Alzheimer’s disease and other forms of dementia who were living in Sweden. Their mean age was 78.
During an average follow-up period of about four years, about 23 percent of them were prescribed an antidepressant drug. The most common antidepressants were in a class of drugs called selective serotonin reuptake inhibitors, or SSRIs. These drugs boost levels of the “feel-good” chemical serotonin in the brain.
Doctors monitored patients’ memory and thinking skills using the Mini-Mental State Exam, a commonly used questionnaire to measure mental acuity. They found that those on antidepressants tended to show more rapid declines than those who weren’t taking the drugs. Patients with more severe dementia appeared to show the greatest cognitive declines.
Some antidepressants seemed to affect cognition more than others. The SSRI escitalopram (brand name Lexapro) was associated with the fastest cognitive decline, followed by the SSRIs citalopram (Celexa) and sertraline (Zoloft). Mirtazapine (Remeron, Remeronsoltab), which alters different chemicals in the brain, had less of an impact on cognition than escitalopram.
In addition, patients on the highest doses of SSRIs tended to have the greatest cognitive decline. They were also more likely to have more bone fractures, a common result of falls.
The study was observational, so it is impossible to determine whether the antidepressants caused the cognitive decline. Depression itself can dull memory and thinking skills, and some of the patients on antidepressants may have had more advanced levels of dementia.
It is possible that people with Alzheimer’s disease may respond better to some antidepressants than others. “The goal is to find these subgroups to create more individualized care,” said Dr. Ptacek. The findings were published in the journal BMC Medicine.
Experts caution that more research is needed to better understand the risks and benefits of antidepressants for people with Alzheimer’s. Agitation, aggression and other behavioral issues typically become more common as the disease progresses and can be a tremendous stress for patients and family members. Antidepressants may help to ease mood and behavioral issues and allow people with Alzheimer’s to be cared for at home longer.
It is important for people with Alzheimer’s or another form of dementia who have been prescribed SSRIs to continue taking the medication and talk with their doctor about any concerns. In many cases, the benefits of taking the drugs to treat depression and anxiety symptoms outweighs the risk of the negative cognitive effects.
By ALZinfo.org, The Alzheimer’s Information Site. Reviewed by Eric Schmidt, Ph.D. Fisher Center for Alzheimer’s Research Foundation at The Rockefeller University.
Source: Minjia Mo, Tamar Abzhandadze, Minh Tuan Hoang, et al: “Antidepressant use and cognitive decline in patients with dementia: a national cohort study”, BMC Medicine, February 25, 2025
