Antidepressants and Dementia

Dementia is a general term that represents a group of progressive diseases that can affect thinking, memory, personality, mood, and behavior. To help alleviate some of the symptoms of dementia, medical professionals often prescribe antidepressants. With the prevalence of dementia increasing due to an aging global population, evaluating antidepressant safety and efficacy is essential. In particular, one area of concern is the potential link between antidepressant medications and the development of dementia.

The Use of Antidepressants for Dementia

The relationship between antidepressant use and the risk of dementia is complex and isn’t yet fully understood. Healthcare providers commonly prescribe antidepressants to manage the depression, anxiety, and agitation that can accompany dementia. While they don’t cure psychiatric disorders or mood disorders, antidepressants help relieve symptoms by altering the balance of certain neurotransmitters in the brain (specifically serotonin, norepinephrine, and dopamine) that affect mood and emotions ^[1]. 

Types of antidepressants used as treatment options for dementia include ^[1]:

• Monoamine Oxidase Inhibitors (MAOIs): MAOIs are the oldest form of antidepressants, and while they can be very effective, they’re typically only used when other treatments haven’t worked. 
• N-methyl-D-aspartate (NMDA) Antagonists: These drugs block NMDA receptors in the brain and help control mood, learning, and memory.
• Selective Serotonin Reuptake Inhibitors (SSRIs): These are the most common type of antidepressants and are typically prescribed for moderate and severe depression. They are thought to cause fewer side effects than other types of antidepressants.
• Serotonin and Norepinephrine Reuptake Inhibitors (SNRIs): Introduced in the mid-90s, SNRIs are thought to be an effective medication for those who’ve had unsuccessful treatment with SSRIs. They’re also used to treat anxiety.
• Tricyclic Antidepressants (TCAs): TCAs are an older class of antidepressants reserved for treatment-resistant depression and anxiety due to increased rates of side effects.

Since people can often remain on these medications for years or even decades, researchers recognized the need to explore the potential cumulative effects of antidepressants, including cognitive decline and dementia risk ^[2].

Studies Linking Antidepressants and Dementia

Dementia symptoms can worsen cognitive decline and impair quality of life, so proper treatment is important. Antidepressants have been linked to cognitive decline and dementia, but findings have been mixed so far.

While scientists still need to conduct larger studies with broad participant representation, strict controls, and rigorous follow-up before an association between antidepressants and cognitive decline can be verified, there is evidence to indicate that there is an existing link. The research conducted on selective serotonin reuptake inhibitors (SSRIs), anticholinergic antidepressants, and benzodiazepines is particularly compelling. 

Study on SSRIs and Dementia

Using data from 18,740 patients in the Swedish Dementia Registry, researchers found that people taking antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs), experienced a faster rate of cognitive decline than those who did not take these medications ^[3]. 

Published in 2025, the study analyzed dementia patients who were newly prescribed antidepressants after their diagnosis ^[3]. They followed the participants over time to assess how their cognitive abilities changed, testing their cognitive function with a screening tool called the Mini-Mental State Examination (MMSE). The study also found that some SSRI antidepressants had a greater impact on memory and cognition than others, with effects being more pronounced in patients with severe dementia ^[3]. Additionally, higher doses of these medications were associated with an increased risk of severe dementia, fractures, and death ^[3]. 

Researchers also noted that study participants who used antidepressants experienced a greater cognitive decline over time compared to those who did not use antidepressants ^[3].

Study on Anticholinergic Drugs and Dementia

Many over-the-counter and prescription drugs have anticholinergic properties, meaning they block a neurotransmitter known as acetylcholine. These medications are commonly used by older adults, particularly those diagnosed with dementia ^[4]. This includes antidepressants with anticholinergic effects.

Researchers tracked nearly 3,500 adults aged 65 and older in the Adult Changes in Thought (ACT) study, using pharmacy records to identify the medications they had taken in the 10 years prior to enrollment ^[5]. 

Each participant was tracked for an average of seven years. Over that time, 800 developed dementia. When researchers examined their medication use, the people who used anticholinergic drugs more often developed dementia. What’s more, their dementia risk increased the longer they took the medication. For example, taking an anticholinergic drug for three years or more was associated with a 54% higher dementia risk than taking the same dose for three months or less ^[5].

The following antidepressants are associated with higher anticholinergic effects ^[5]:

• Amitriptyline: A tricyclic antidepressant (TCA) medication frequently cited for strong anticholinergic properties
• Paroxetine: A selective serotonin reuptake inhibitor (SSRI) with the highest anticholinergic activity in its class
• Doxepin: A sedating antidepressant with significant anticholinergic effects
• Imipramine: Another TCA medication that has anticholinergic activity and is linked to memory issues in long-term use

Study on Benzodiazepines and Dementia

A team of researchers from France and Canada linked the use of benzodiazepines to an increased risk of being diagnosed with dementia, specifically Alzheimer’s disease. Benzodiazepines are a class of central nervous system (CNS) depressant drugs sometimes used in the treatment of depression. In the study, the higher the dose of benzodiazepines, the higher the participant’s risk of developing dementia ^[6].

Researchers relied on a database maintained by the Quebec health insurance program to identify nearly 2,000 men and women over the age of 66 who had already been diagnosed with Alzheimer’s disease ^[6]. Next, they randomly selected more than 7,000 others who had not been diagnosed with Alzheimer’s, but were matched in terms of age and sex to study participants with the condition ^[6]. 

People who had taken a benzodiazepine for three consecutive months or less had about the same dementia risk as those who had never taken one ^[6]. However, those who had taken a benzodiazepine for three to six months had a 32% greater risk of developing dementia, while those taking one for more than six months faced an 84% greater chance of developing the condition ^[6]. People who were prescribed a long-acting benzodiazepine like diazepam (Valium) or flurazepam (Dalmane) were at greater risk than those prescribed a short-acting one like triazolam (Halcion), lorazepam (Ativan), alprazolam (Xanax), or temazepam (Restoril) ^[6].

Recognizing Proven Dementia Risk Factors

It is still too early to say whether antidepressants may cause dementia. It is still under investigation if certain types of dementia or patients with specific genetic markers respond better or worse to antidepressants. 

Several medical, genetic, and lifestyle factors are known to play a role in the development of dementia, so it’s important not to isolate antidepressants as the sole focus of prevention efforts. By having an understanding of the proven medical conditions that can cause dementia, patients and healthcare providers can work together to actively reduce or eliminate any modifiable risks while also effectively treating any psychiatric or mood disorders.

Some proven risk factors of dementia are ^[7]:

• Age
• Genetics
• Uncontrolled chronic conditions such as high blood pressure, diabetes, and obesity
• One’s amount of “cognitive reserve,” or the brain’s ability to cope with disease
• Exposure to air pollution
• Ethnicity
• Substance abuse or dependency, especially with existing concerns over whether alcohol can cause dementia

Using Antidepressants with Caution and Compassion

While some studies suggest a potential link between antidepressants and dementia, the evidence remains inconclusive and is often confounded by other factors. These mixed results emphasize the need for more long-term, controlled studies to untangle the potential impact of antidepressants on the brain. Future research will undoubtedly provide more information about the potential impact of medication use and how it relates to dementia risk. 

With depression being a known risk factor for cognitive decline, treatment is an essential part of dementia prevention for many people. Healthcare providers can provide support by approaching antidepressant use with balance, compassion, and clinical insight. If cognitive concerns arise, exploring options like psychotherapy, medication adjustments, or cognitive screenings can offer peace of mind and proactive health planning.