Antidepressants for Alzheimer’s Disease

Alzheimer’s disease is known to cause symptoms that affect memory. But it can also cause behavioral symptoms. Depression is a common behavioral symptom in people living with Alzheimer’s.¹

But depression can be hard to diagnose in those with Alzheimer’s disease. It may have signs that overlap with those of Alzheimer’s, like trouble focusing. Or it may present differently than depression in those who do not have Alzheimer’s. For example, those with dementia often express depression as agitation. What looks like depression can even be a drug side effect.^1,2

Doctors are cautious when diagnosing and prescribing drugs for depression in people with Alzheimer’s disease. They perform thorough mental and physical exams. They often rely on caregivers for important information about the person’s behavior. If they do diagnose depression, they may prescribe an antidepressant drug to treat it.^1,2

How do antidepressants work?

In general, antidepressants change the levels of chemicals in the brain called neurotransmitters. These chemicals carry messages from nerve cells. They help regulate many bodily functions, including mood.^3,4

The most common type of antidepressant prescribed for people with dementia is selective serotonin reuptake inhibitors (SSRIs). Compared with other types of antidepressants, SSRIs interact less with other drugs. They may also have fewer side effects. This is why doctors often prefer to prescribe SSRIs.^1,2

SSRIs work by blocking the absorption of the neurotransmitter called serotonin. Normally, after serotonin delivers its message, a nerve cell will absorb it. SSRIs block this process. This boosts the overall amount of serotonin available for the brain to use. This can help relieve symptoms of depression.^3,4

Examples

At this time, the SSRIs approved by the US Food and Drug Administration (FDA) to treat depression are:^4,5

• Citalopram (Celexa^®)
• Escitalopram (Lexapro^®)
• Fluoxetine (Prozac^®)
• Paroxetine (Paxil^®)
• Sertraline (Zoloft^®)
• Vilazodone (Viibryd^®)
• Vortioxetine (Trintellix^®)

Some studies suggest that citalopram is the SSRI that works best for treating depression in people with dementia.^2,6

What are the possible side effects?

Side effects can vary based on the specific drug you are taking. Common side effects of SSRIs include:^4,5

• Upset stomach, including throwing up or diarrhea
• Headache
• Agitation or anxiety
• Dizziness
• Shaking or trembling
• Tiredness or drowsiness
• Sweating
• Changes in appetite
• Decreased sexual desire or function

Another possible side effect of SSRIs is serotonin syndrome. This severe condition results from having too much serotonin in the body. Serotonin syndrome can be life-threatening and needs emergency medical treatment. It may cause:⁴

• Muscle spasms
• Racing heart
• Fever
• Confusion
• Other symptoms

All antidepressants have a boxed warning. This is the strictest warning from the FDA for a drug. They have this warning because they can increase the risk of self-harm and thoughts of suicide, especially in young people.^4,5

These are not all the possible side effects of SSRIs. Talk to your doctor about what to expect when taking SSRIs. You should also call your doctor if you have any changes that concern you when taking an SSRI.

Other things to know

There is not much evidence that antidepressants work in people with dementia. Research shows that taking an antidepressant may increase their risk of falling, being hospitalized, and even dying. Because of this, doctors will need to weigh the possible risks against the benefits before prescribing an antidepressant.^2,7

SSRIs may take weeks to begin taking effect. During this time, the side effects may be the strongest. Do not stop taking an SSRI abruptly. Stopping too quickly can cause withdrawal symptoms. Work with your or your loved one’s doctor to wean off of the drug slowly.⁴

Caregivers play a very important role in seeking treatment for a person with Alzheimer’s disease. If their language skills are impaired, the person may not be able to report their own symptoms. If their memory has declined, they may not remember having symptoms.^1,2,6,7

Caregivers should report any symptoms of depression that they observe to their loved one’s health team. They can also help monitor their loved one for drug side effects.^1,2

SSRIs can have dangerous interactions with other drugs. Before starting treatment for Alzheimer’s disease, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you take. This includes over-the-counter drugs.^4,5