Antidepressants may hasten decline from dementia, study says. Experts are unconvinced

Dementia goes hand-in-hand with depression, anxiety and mood swings. Doctors often use antidepressants to control those symptoms so patients can function longer. (Wavebreakmedia/iStockphoto/Getty Images via CNN Newsource)

Doctors often use antidepressants to manage the depression, anxiety and agitation that accompanies a diagnosis of dementia. Now, a new study suggests the use of antidepressants may hasten the cognitive decline of people with dementia. It’s a conclusion that some experts consider unwarranted.

“We found that patients with dementia who took antidepressants had greater cognitive decline over time,” said senior study author Sara Garcia Ptacek, an assistant professor in neurosciences at the Karolinska Institute in Solna, Sweden.

However, patients and their caregivers should not overreact to the findings as the study was observational and more research needs to occur, Ptacek said in an email.

Experts not involved with the study agree the study’s findings should be interpreted with caution.

“The severity of depression in dementia patients wasn’t fully accounted for, which has the potential to bias the results”, said Dr. Prasad Nishtala, a reader in the department of life sciences at the University of Bath in the United Kingdom, in a statement.

Preventive neurologist Dr. Richard Isaacson, director of research at the Institute for Neurodegenerative Diseases in Boca Raton, Florida, said doctors who treat dementia aren’t likely to change their practices based on this study.

What the public hears and acts on, however, is a different concern, Isaacson said.

“As a clinician, the worrisome thing is that a patient’s loved one will hear about this study and say, ‘Oh if we use an antidepressant, my mom will decline faster,’” he said.

“Then what happens to the patient’s quality of life? Could they become more agitated and be a danger to be kept at home?” Isaacson continued. “Could they become more withdrawn, socially restricted and apathetic? Very probably.”

Confusing results

The study, published Monday in the journal BMC Medicine, analyzed medical data from 2007 to 2018 on 4,271 people with dementia enrolled in the Swedish Registry for Cognitive/Dementia Disorders, a repository on dementia research. All the participants had been on antidepressants for at least six months before the study began. Selective serotonin reuptake inhibitors, known as SSRIs, were the most common antidepressants prescribed.

The more severe the dementia, the stronger the association between antidepressant use and cognitive decline, the study said.

“However, a major limitation of the study is that the researchers didn’t know if the people that needed antidepressants were more severe and more likely to decline in the first place,” Isaacson said.

More importantly, tests of cognitive decline administered during the study showed patients on commonly used antidepressants actually declined more slowly than what is typical for dementia patients overall, Isaacson said.

Cognitive decline among patients in the study who used antidepressants was measured by the Mini‐Mental State Examination, a standard test for mental acuity. The 11 questions on the test gauge five areas of cognitive function. The maximum score is 30, and a score of 23 or lower is indicative of cognitive impairment.

Typically, the cognition of people with dementia declines between one and three points a year on the test. Yet the patients using certain antidepressants in the study declined less than a point a year – a much slower rate than the typical person with dementia.

“It’s like the study contradicts itself,” Isaacson said. “If someone reads this research and concludes antidepressants fast-forward cognitive decline in people with dementia, that’s bogus. That’s not what this study says.”

Much more research needs to be done before an association between antidepressants and cognitive decline can be verified, said Dr. Emma Anderson, an associate professor of epidemiology and genetic epidemiology at University College London, in a statement. She was not involved in the study.

“When based on limited evidence, these claims can be very damaging for public understanding of antidepressants, which we know help millions of people around the world.”

Article written by Sandee LaMotte, CNN