Understanding the Link Between Dementia and Depression

Research indicates that depression is linked to an increased risk of dementia. However, this research is still ongoing and needs to be investigated further. Let’s review some recent findings.

A 2020 study conducted in Sweden compared dementia risk in people with and without depression. The study found that people with a diagnosis of depression were at a higher risk of developing dementia.

The risk of dementia appeared to be highest in the first year after a diagnosis of depression. After that, the risk decreased rapidly with time. However, it was still elevated more than 20 years after the diagnosis of depression.

Researchers involved in a 2019 study also found links between depression and dementia. This study included 11,472 older adults throughout Latin America, 26 percent of whom had depression or depressive symptoms.

Both depression and depressive symptoms were found to be associated with an increased risk of dementia in this group. But this study didn’t account for the fact that depression can also be a symptom of dementia.

A 2021 study used statistical modeling to look at the effect of depressive symptoms on cognition in four groups of people whose ages ranged from 20 to 89 years old. The goal of this study was to find an association between depressive symptoms at different stages of life and cognitive impairment.

Researchers found that elevated depressive symptoms in early adulthood (ages 20 to 49), as well as in later life (ages 70 to 89), were associated with cognitive impairment in late life as well as a faster rate of cognitive decline.

The effects of dementia can have a great impact on a person’s mood and emotions as they try to cope with their cognitive changes. This means that depression can also appear as a symptom of dementia.

Depression as a symptom of dementia isn’t uncommon. A 2015 review notes that up to 40 percent of people with dementia can experience depression.

Many dementia symptoms also overlap with depression symptoms, including:

• having difficulty with memory and concentration
• feeling depressed, down, or helpless
• losing interest in previously enjoyable activities
• isolating yourself from others

Due to the significant overlap in symptoms, depression can be hard to diagnose in people with dementia.

A 2019 review of studies notes that older individuals with depressive symptoms, particularly those with Alzheimer’s disease, don’t always meet the classic diagnostic criteria for major depression.

Treating depression in people with dementia can be complicated. People with dementia often have difficulty remembering things and focusing, which can make talk therapy difficult. But this may benefit some people.

A 2019 review of studies suggests that antidepressant medication is often ineffective at treating depression in people with Alzheimer’s disease.

Common antidepressants include:

• selective serotonin reuptake inhibitors (SSRIs)
• serotonin and norepinephrine reuptake inhibitors (SNRIs)
• tricyclic antidepressants (TCAs)
• monoamine oxidase inhibitors (MAOIs)

When doctors do prescribe antidepressants to people with dementia, they need to monitor them closely. This is because it can be difficult to observe the effects of psychiatric medications in people with dementia.

Lifestyle changes can also be difficult for people with dementia, but friends, family, and caregivers can help. Examples of constructive lifestyle changes include:

• continuing to stay active
• staying socially engaged and avoiding isolation
• trying out ways to relax and reduce stress, such as yoga or meditation
• reaching out to your support network, such as your friends and loved ones

There’s currently no cure for dementia. But managing this condition can help improve quality of life.

Medications known as acetylcholinesterase inhibitors can slow the progression of dementia, including:

• donepezil (Aricept)
• galantamine (Razadyne)

The support of loved ones and caregivers is also essential. Ways you can help include:

• helping to maintain an individual’s independence as long as possible
• helping with daily activities and personal care
• encouraging activities that provide mental and social stimulation
• managing the mood, behavioral, and sleep symptoms associated with dementia
• managing other health conditions and treatments

Whether they’re occurring separately or together, symptoms of dementia and depression need to be evaluated by a healthcare professional. Here are some signs that it’s time to look for care.

Dementia symptoms

Dementia symptoms can vary by individual. They may appear subtle at first, before becoming more noticeable as time passes. Look out for:

• increased forgetfulness, which can include:
  • forgetting where you put things
  • difficulty recalling events or people’s names
  • getting lost in places that should be familiar to you
  • repeating questions
  • losing track of time
• problems with decision making or problem solving
• trouble speaking or expressing thoughts
• difficulty with or needing help with daily tasks
• changes in mood, which can include things such as depression, anxiety, or agitation
• trouble with movement and balance

Depression symptoms

Depression symptoms impact a person nearly every day for at least 2 weeks. They can include:

• persistent depressed mood
• feelings of pessimism, worthlessness, or helplessness
• agitation or restlessness
• loss of interest in activities that normally provided happiness
• low energy levels
• sleep changes, such as sleeping too much or very little
• trouble with concentration, memory, or decision making
• extreme changes in eating habits that can lead to noticeable weight loss or weight gain
• thoughts of death or suicide

Dementia and depression are closely linked. Some research suggests that having depression earlier in your life is a risk factor for developing dementia later on.

Depression can also be a symptom of dementia, particularly in the early stages of dementia. But because there’s a lot of overlap between the symptoms of the two conditions, it can be hard to diagnose depression in some people with dementia.

Whether they happen separately or together, people with symptoms of dementia or depression should be evaluated by a healthcare professional. Prompt, early treatment can help improve quality of life.