Does Parkinson’s Disease Cause Dementia?

There is a link between Parkinson’s disease and dementia as it is common for people with Parkinson’s disease to go on to develop dementia. As Parkinson’s progresses, the changes occurring in the brain can begin to affect cognitive function, leading to difficulties with memory, thinking, and decision-making. 

Dementia is an umbrella term referring to a collection of symptoms relating to cognitive decline including changes in memory and thinking.

Parkinson’s disease dementia (PDD) is a decline in cognitive skills such as memory, reasoning, and thinking, that can develop in someone who has been diagnosed with Parkinson’s disease. These dementia symptoms will typically appear a year or more after the person’s initial Parkinson’s diagnosis. 

The brain changes associated with Parkinson’s disease begin in the part of the brain responsible for controlling movement. As a result, the early symptoms will be related to motor skills. For example, tremors, muscle stiffness, difficulty walking, and reduced facial expression. 

As the disease progresses and these changes spread to other areas of the brain, individuals may also experience difficulties with cognitive functions, including memory, attention, judgment, and the ability to plan and carry out tasks. It is often at this point that they are diagnosed with Parkinson’s disease dementia. 

Lewy body dementia (LBD) is caused by tiny protein deposits in the brain which build up in the nerve cells causing problems with thinking, memory, and movement. Due to this build-up, the nerve cells can’t work as well as expected, and eventually they will die.

This form of dementia can share symptoms with other types of dementia including problems with thinking and memory, but the main symptoms usually associated with Lewy body dementia are:

• Visual and/or auditory hallucinations
• Confusion
• Unpredictable changes in alertness 
• Fainting and/or falls
• Problems with movement (stiff limbs, slow movement, tremors, unsteadiness)
• Disturbed sleep
• Depression or anxiety

The disease that causes Parkinson’s is very similar to the one that causes dementia with Lewy bodies and the symptoms often overlap. Because of this, these two conditions are easily confused. The main difference between these two diagnoses is the timing of the symptoms. 

Dementia with Lewy bodies: Visual hallucinations and symptoms connected to thinking and alertness develop early in relation to movement symptoms such as slowness, difficulty walking and muscle stiffness. 

Parkinson’s disease dementia: Symptoms concerning movement and consistent with Parkinson’s disease appear first. Parkinson’s disease dementia may then develop later on and the person will experience dementia symptoms such as those relating to thinking, memory and/or changes in mood or behaviour.

These changes in cognitive ability can start to make daily life and activities more difficult, especially as the condition progresses. 

Difficulties with attention, memory, problem-solving, and decision-making can affect a person's ability to manage everyday tasks. Some individuals may also find it harder to multitask, process information quickly, or adapt to changes in routine. As cognitive symptoms worsen, they can impact confidence, relationships, and overall quality of life. 

However, people experiencing difficulties in daily life can often still live at home and continue their usual routines with assistance from family members, friends, or professional Carers. Early recognition of cognitive changes is important, as appropriate support, treatment, and practical strategies can help individuals maintain their independence and wellbeing for as long as possible. 

At Right at Home, we focus on helping people live well with Parkinson’s disease dementia and other conditions, rather than simply managing the symptoms. By taking the time to understand each Client’s unique life story, preferences, and daily routines, we provide personalised support that promotes dignity, independence, and quality of life.

At Right at Home, we build meaningful relationships with every Client, focusing on what matters most to them. 

During the early stages of Parkinson’s you may need occasional support. This could include daily visits to help with meal preparation or getting ready in the morning. As the condition progresses we offer more involved care such as live-in care and 24-hour care.

Our Care Assistants are trained in Parkinson’s care and dementia care, and work closely with you, your family, and health professionals to ensure your needs are fully met.

We offer:

• Personalised care plans that adapt as needs change
• Familiar Carers who understand each Client’s routines, preferences, and personality
• Specialist training in dementia care, including communication techniques and behaviour support
• Engaging activities that promote memory, independence, and joy
• Support with gentle exercise to promote physical wellbeing
• Family support through education, respite care, and regular updates
• Flexible services, from hourly visits to live-in care, to match the right level of support with your needs

We believe the best support is about more than managing symptoms — it’s about promoting independence, maintaining dignity, and helping people continue living life on their own terms.