- A new study investigated the impact of antidepressants on cognitive decline in dementia patients.
- The researchers studied nearly 19,000 people diagnosed with dementia, and around 23% received antidepressants as a treatment for depression.
- The study showed that cognitive decline was worse in people who took antidepressants than in people who did not take one.
- The scientists also discovered that certain types of antidepressants may contribute to faster cognitive decline than others.
Dementia affects millions of people, and scientists are working to develop early detection of dementia and more effective treatments. They are also looking for ways to reduce the severity of symptoms, including slowing the progression of symptoms.
Researchers based in Sweden recently completed a study of people diagnosed with dementia. They examined the role antidepressants may have on dementia symptoms, chiefly cognitive decline.
The study findings showed that antidepressants may speed up cognitive decline in these patients. The researchers were careful to note that depression alone could contribute to the more rapid cognitive decline, and they also noticed a difference in the decline depending on the antidepressant that was prescribed.
The study appears in
Dementia risk increases with age, and according to the
Alzheimer’s disease is the most prevalent form of dementia. Other dementia types include frontotemporal dementia and Lewy body dementia.
Some symptoms of dementia include:
- memory loss
- getting locations, dates, and names confused
- changes in mood
- losing items
- difficulty speaking and writing.
There is no cure for this condition, but between early diagnosis and interventions, providers can help patients manage symptoms with certain medications and therapies.
Since changes in mood are common with dementia, depression is common and occurs in an estimated 30 to 50% of people with the disease.
Doctors often prescribe antidepressants to help manage depression symptoms. Some popular options are selective serotonin reuptake inhibitors or SSRIs (sertraline and fluoxetine), tricyclic antidepressants (amitriptyline and amoxapine), and serotonin-norepinephrine reuptake inhibitors or SNRIs (duloxetine and desvenlafaxine).
The authors of the new cohort study wanted to find out whether it is possible for antidepressants and antidepressant classes to impact the rate of disease progression. They noted that prior studies were limited in scope and had inconclusive findings and that the clinical efficacy of the antidepressants was unclear.
The researchers used data from the Swedish Registry for Cognitive/Dementia Disorders (SveDem), collected between 2007 and 2018, for their analysis. Of the 18,740 dementia patients included in the study, approximately 23% were on antidepressants.
The participants had a mean age of 78.2 years, and 54.5% of the participants were women. All participants had at least one follow-up visit after receiving their dementia diagnosis.
To track cognitive changes, the researchers utilized Mini-Mental State Examination (MMSE) scores that were recorded both at the time the dementia diagnosis was documented and at follow-ups.
The researchers analyzed not only the rate of cognitive decline in people who took antidepressants versus those who did not but the difference in medication classes as well.
The researchers discovered there may be a link between antidepressant use and an increase in the rate of cognitive decline in dementia patients. The decline rate for all categories of antidepressants and all types of dementia on the MMSE screening was a differential of 0.30 points per year.
Additionally, the scientists found a difference in cognitive decline depending on the class of antidepressants the participants took.
People who took SSRIs experienced faster cognitive decline than people who took SNRIs or tricyclic antidepressants. Mirtazapine (Remeron), an atypical antidepressant, had a less harmful impact on cognitive functioning.
When focusing on only mediations in the SSRI class, escitalopram (Lexapro) was linked to a faster decline than sertraline (Zoloft). Meanwhile, people who took citalopram (Celexa) experienced a slower decline.
Also, the researchers found an association between higher doses of SSRIs and a higher risk of severe dementia, fractures, and all-cause mortality.
The study further examined factors such as sex and baseline cognitive function. They found that the effect of antidepressant use on cognitive decline was more pronounced in men and individuals with lower baseline MMSE scores.
While these findings demonstrate a possible connection between taking antidepressants and worse outcomes in dementia, it is important to note that this is only an association, and more research is needed.
The researchers are unsure whether the medications are the cause of the increased cognitive decline or if it is a matter of depression and other neuropsychiatric issues causing problems.
Aanand Naik, MD, a geriatrician and executive director of the Institute on Aging at UTHealth Houston, who was not involved in the research, spoke with Medical News Today about this study.
Naik advised that further research is necessary before becoming overly concerned with the findings.
“I would be cautious about overinterpreting these results,” he emphasized, speaking about the study design:
“The study designs the authors used is a population-based cohort with trends over time in a large nationally representative sample. I’m not clear from this study that using depression medications causes cognitive decline.”
While Naik acknowledged that the study shows cognitive decline on the MMSE, he thought that “the need for depression medication likely heralds the onset of worsening behavioral symptoms and progression of dementia.”
David Merrill, MD, a board-certified geriatric psychiatrist at Providence Saint John’s Health Center in Santa Monica, CA, and Singleton Endowed Chair in Integrative Brain Health, also spoke with MNT to provide insights on the study.
Merrill, who was likewise not involved in this study, also emphasized that further research is needed on this topic, but did explain a reason why patients on antidepressants could have some degree of cognitive decline.
“One possibility is that SSRIs may influence neurotransmitter systems in ways that exacerbate cognitive deterioration,” said Merrill. “Additionally, the depressive symptoms themselves, which these medications aim to treat, might inherently contribute to cognitive decline, making it challenging to disentangle the effects of the medication from the underlying condition.”
When asked whether these findings should influence clinical practice for prescribing antidepressants in people with dementia, Merrill advised a “careful, individualized approach.”
“Clinicians should thoroughly assess the severity of depressive symptoms and consider non-pharmacological interventions, such as psychotherapy or behavioral therapies, as first-line treatments,” he recommended. “If antidepressant medication is deemed necessary, selecting agents with a more favorable cognitive profile and closely monitoring the patient’s cognitive function over time is essential.”
