“Mixed dementia” refers to a condition in which more than two types of dementia are present. Alzheimer’s disease and vascular dementia are the most common.

Dementia is a syndrome caused by changes in your brain. It affects basic cognitive functions, such as memory, reasoning, and thinking skills.

Unlike age-related cognitive changes, dementia can lead to a loss of basic functioning and independence. Mixed dementia is a type of dementia consisting of at least two dementias.

This article reviews risk factors for mixed dementia, along with symptoms and management. Talk with a doctor about mixed dementia if you’re concerned about yourself or a loved one. You can use the information in this article to start the conversation.

“Mixed dementia” refers to changes in the brain caused by more than two types of dementia. This can include brain changes from two or more of the following:

Alzheimer’s disease is caused by abnormal protein deposits in the brain. Vascular dementia is a result of recurrent strokes that are caused by abnormal blood vessels in the brain. When combined, a person can have both types of changes.

It’s not clear how common mixed dementia is when compared with other types, but research based on autopsies suggests that mixed dementia may be much more common than experts once believed.

Such findings highlight the need for more effective means of mixed dementia diagnosis, especially since many of the symptoms are similar to other forms of dementia.

In many cases, symptoms of mixed dementia are often similar to Alzheimer’s disease, but the exact symptoms a person experiences with mixed dementia depend on which area of the brain is affected.

Some of the possible symptoms of mixed dementia include:

  • memory loss
  • losing everyday items
  • repeating questions
  • difficulty with everyday tasks
  • loss of language skills
  • mood and personality changes
  • difficulty with reading and writing
  • hallucinations
  • suspiciousness
  • social withdrawal
  • difficulty sleeping
  • impaired perception of danger or excessive fear of danger
  • walking difficulties
  • reduced coordination
  • stooped posture (as seen in Lewy body dementia)

How quickly does mixed dementia progress?

Like other types of dementia, mixed forms are progressive, though there’s no set timeline of progression. While Alzheimer’s disease may progress slower than other dementias, vascular dementia may progress rapidly, particularly in cases of stroke.

Also, symptoms of mixed dementia may seem to progress quickly due to the presence of multiple dementias.

As with all types of dementia, age is the greatest risk factor for mixed dementia. It’s estimated that dementia among Americans may double by the year 2050 due to the number of adults who will reach age 65 years and older.

Mixed dementia is most common in adults more than 85 years of age.

Overall, the risk factors for mixed dementia are similar to other dementias, though blood and heart diseases may increase the risk of vascular issues with mixed dementia.

Aside from age, other risk factors for mixed dementia may include:

Also, some researchers believe that symptoms are more likely to be present in mixed dementia because of multiple effects on the brain. These dementias include Alzheimer’s disease along with blood clots related to vascular dementia and/or Alzheimer’s disease with the presence of Lewy bodies.

Similar to other types of dementia, there’s currently not a mixed dementia-specific treatment available.

A doctor may recommend the following management tips for mixed dementia:

  • Cholinesterase inhibitors: These medications may help treat symptoms of Alzheimer’s disease by improving thinking and memory skills. They may also help treat symptoms of Lewy body and vascular dementias.
  • Medications for stroke prevention: Blood thinners and high blood pressure medications may benefit vascular dementia by reducing the chances of a stroke.
  • Other medications to alleviate symptoms: These medications include antidepressants and sleep aids. Others may help treat muscle stiffness or anxiety.
  • Physical and occupational therapies: Such therapies can help with everyday tasks, such as walking, eating, and getting dressed.

Overall, the outlook for people with mixed dementia varies based on:

  • when the symptoms begin
  • how far the dementia progresses before receiving an official diagnosis
  • the presence of other chronic conditions, such as heart disease or diabetes
  • whether there’s vascular involvement, as this may increase the risk of a life threatening heart attack or stroke

The average life expectancy may also vary based on the types of brain changes that have caused mixed dementia, as follows:

One 2018 study also found that the outlook for people with mixed dementia and vascular involvement was the shortest of all dementias. Here, researchers estimated an average life span loss of 10 years.

It’s estimated that one-third of all adults more than 85 years of age have at least one type of dementia. This statistic includes mixed dementia, which involves having at least two types. Despite being widespread among older adults, this syndrome isn’t considered “normal” with age.

While there are currently no preventive measures or cures for mixed dementia, it’s important to talk with a doctor if you or a loved one has risk factors or symptoms of this condition. Early support and management can significantly improve your quality of life.