Parkinson’s Disease and Dementia: Symptoms, Causes, Treatments

Parkinson's disease dementia is more common than you think. Learn everything you need to know about Parkinson's and dementia on HealthyPlace.

Parkinson's disease dementia affects over half of Parkinson's disease patients. While this statistic may be frightening, it's important to remember that the majority of people diagnosed with Parkinson's are over the age of 65 – a factor that significantly raises their risk of dementia, with or without PD. All the same, dementia can severely impact your quality of life with Parkinson's, so it's important to stay informed and have a solid care team around you. Let's look at the definition of Parkinson's disease dementia and explore the signs and symptoms.

What Is Parkinson’s Disease Dementia?

Parkinson's disease is a neurological disorder characterized by the decline of dopamine cells in the brain. In addition to causing tremor, rigidity and slowed movement, Parkinson's disease can also cause Parkinson's disease dementia. Like regular dementia, this condition is marked by cognitive symptoms like confusion and memory loss.

Scientists have found that, as Parkinson's disease progresses, the loss of dopamine cells affects not only the parts of your brain responsible for movement but also the areas that control memory, judgment and mental functioning. This is why many people in the late stages of Parkinson's experience symptoms of dementia.

Parkinson’s Disease Dementia: Signs and Symptoms

Parkinson's disease dementia affects 50-80 % of people diagnosed with Parkinson's disease. According to the Alzheimer's Association, the signs and symptoms include:

  • Changes in memory, concentration and judgment
  • Muffled speech
  • Visual hallucinations
  • Difficulty interpreting visual information (not recognizing photos or faces)
  • Delusions
  • Paranoid ideas (thinking people are trying to hurt you or that people aren’t who they say they are)
  • Depression
  • Anxiety
  • Irritability
  • Sleep disturbances, including excessive daytime drowsiness

See Also: Parkinson’s Disease and Psychosis: Hallucinations, Delusions

Most people with Parkinson's disease dementia are unable to spot these symptoms in themselves. This is why it's essential to have a solid healthcare team in place and ensure your loved ones are aware of the tell-tale signs.

It's also worth noting that many of these changes are also symptomatic of Parkinson's disease without dementia – particularly mood changes and sleep disturbances. Your doctor should keep a close eye on the progression of your illness and watch out for signs of Parkinson's disease dementia.

What Are the Risk Factors of Parkinson’s Disease Dementia?

If you are diagnosed with Parkinson's disease, you may worry about developing Parkinson's disease dementia. While not everyone with PD experiences dementia, certain factors can increase your risk. These include:

Although every case of Parkinson's disease is different, the Alzheimer's Association suggests that the average time between being diagnosed with Parkinson's and developing Parkinson's disease dementia is around ten years.

What's the Link Between Parkinson's Disease and Dementia?

No one knows quite what causes Parkinson's disease or Parkinson's disease dementia. However, both Parkinson's disease and dementia are thought to be characterized by Lewy bodies in the brain. These Lewy bodies, first identified in Dr. Alois Alzheimer's laboratory in the early 1900s, are described as abnormal clumps of protein found in the cortex of the brain. They are also present in several other brain disorders, including Lewy body dementia (LBD).

There is currently no cure for Parkinson's disease or Parkinson's disease dementia. However, scientists are working on several clinical trials to try to change this. If you want to get involved in clinical trials or research, visit the Michael J. Fox Foundation for Parkinson's Research.

article references

APA Reference
Smith, E. (2022, January 27). Parkinson’s Disease and Dementia: Symptoms, Causes, Treatments, HealthyPlace. Retrieved on 2024, July 21 from

Last Updated: January 27, 2022

Medically reviewed by Harry Croft, MD

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