Is There a Link Between Parkinson’s Disease and Alzheimer’s Disease?

Parkinson’s disease and Alzheimer’s disease are two of the most common neurodegenerative disorders affecting older adults. Because both conditions impact the brain and can cause changes in memory, thinking, and daily functioning, many people wonder whether there is a connection between them.
Could Parkinson’s disease increase the risk of cognitive decline? And if someone has Parkinson’s, does that mean they will develop Alzheimer’s disease? The relationship between these two conditions is more complex than many people realize. Understanding the similarities and differences can help individuals and families better navigate diagnosis, treatment, and long-term care planning.

Are Parkinson’s Disease and Alzheimer’s Disease the Same?
No. Parkinson’s disease and Alzheimer’s disease are separate neurological disorders with different primary symptoms and underlying brain changes.
Parkinson’s disease is primarily known as a movement disorder. Common symptoms include:

• Tremors
• Slowed movement (bradykinesia)
• Muscle stiffness (rigidity)
• Balance and coordination problems

Alzheimer’s disease primarily affects memory, thinking, and cognitive function. Early symptoms often include:

• Memory loss
• Difficulty learning new information
• Problems with reasoning and judgment
• Confusion about time or place

While the two diseases are different, they can share some overlapping symptoms as they progress.

Is There a Connection Between Parkinson’s and Alzheimer’s?
Researchers have discovered that both conditions involve abnormal protein buildup in the brain.
In Parkinson’s disease, the primary protein involved is alpha-synuclein, which forms clumps called Lewy bodies.
In Alzheimer’s disease, abnormal accumulations of beta-amyloid plaques and tau tangles damage brain cells.
Although the diseases develop differently, both cause progressive damage to neurons and can affect memory, thinking, mood, and behavior over time.

Can People with Parkinson’s Develop Dementia?
Yes. Some individuals with Parkinson’s disease may develop Parkinson’s disease dementia (PDD), especially in later stages of the disease.
Symptoms of Parkinson’s disease dementia may include:

• Difficulty concentrating
• Slower thinking
• Memory challenges
• Trouble planning and organizing
• Visual hallucinations
• Changes in judgment

However, Parkinson’s disease dementia is not the same as Alzheimer’s disease, even though some symptoms overlap.
What Is Dementia with Lewy Bodies?
Another related condition is Dementia with Lewy Bodies (DLB), which shares characteristics of both Parkinson’s disease and dementia.
People with DLB may experience:

• Cognitive decline
• Visual hallucinations
• Fluctuations in attention
• Parkinson-like movement symptoms

Because these disorders involve similar brain changes, diagnosing them can sometimes be challenging.
What Does the Research Show?
Researchers continue to study the relationship between Parkinson’s disease, Alzheimer’s disease, Parkinson’s disease dementia, and Lewy body dementia.
Current evidence suggests that while Parkinson’s disease does not directly cause Alzheimer’s disease, some individuals may develop cognitive symptoms that resemble those seen in Alzheimer’s. Understanding these differences is important because treatment approaches and care needs may vary.
Why Early Recognition Matters
Recognizing cognitive changes early allows individuals and families to seek medical evaluation, access support services, and develop care plans that promote independence and quality of life.
Regular communication with healthcare providers can help identify changes in memory, thinking, mood, and daily functioning.

Why Support Matters
A diagnosis of any form of Parkinson’s can feel overwhelming. But with the right support and resources, individuals can maintain independence, quality of life, and emotional well-being.
For resources, referrals, and support in navigating Parkinson’s and related conditions, contact the Parkinson’s Association of Southwest Florida at www.paswfl.org or call 239-417-3465.

For over 25 years, PASWFL has provided free, high-quality services and programs to individuals and families touched by Parkinson’s disease in Southwest Florida. Their goal is simple: help people live well with PD, regardless of where they are in their journey.
Each week, PASWFL offers more than 25 free programs and support groups, including:
• Wellness and fitness classes
• Speech Exercise classes
• Educational seminars
• Support for care partners
• Support groups
There are no fees to become a member, and PASWFL welcomes anyone touched by PD.

Take the First Step Toward Living Well
If you suspect early Parkinson’s or have been recently diagnosed, you don’t have to face it alone.
👉 Click here to sign up for the PASWFL newsletter:
https://parkinsonassociationswfl.org/signup-enews.html
👉 Click here to become a member—it’s free and confidential:
https://parkinsonassociationswfl.org/signup.html
To learn more, visit www.paswfl.org and discover the power of support, education, and community.