Two main types of dementia affect people with Parkinson's - they're called Parkinson's dementia and dementia with Lewy bodies.

Item text

Some people develop dementia after living with Parkinson's for some time. If they have had problems with movement for at least a year before experiencing dementia, this is known as Parkinson's dementia.

Dementia with Lewy bodies is diagnosed when someone has the symptoms of dementia either before or at the same time as developing Parkinson's-like problems with movement (called motor symptoms).

But in some cases of dementia with Lewy bodies, no motor symptoms develop at all.

Item text

Symptoms can include forgetfulness, slow thought processes and difficulty concentrating. This can make communication hard, as remembering words and names and following conversations can be a problem.

Some people find it increasingly difficult to make decisions, plan activities and solve problems. This can affect everyday activities such as dressing, cooking or cleaning.

People can also experience changes in their appetite, energy levels and sleeping patterns, so they may find themselves sleeping more during the day, or becoming less engaged with what's going on around them.

A lack of motivation or interest in things they previously enjoyed can also be a symptom.

Problems such as anxiety, depression and irritability can become an issue because of dementia.

Some people may also find it difficult to control their emotions and experience sudden outbursts of anger or distress, although these problems are not common.

Some people with Parkinson's dementia might also develop visual hallucinations and delusions.

Some of the symptoms of Parkinson's dementia are similar to those caused by other health issues. For example, mental health issues such as depression can mimic dementia.

Side effects from medication or medical problems, such as an infection, may be the cause of symptoms similar to dementia, such as memory problems. Symptoms caused by medication or infections can be treated effectively.

It's important to speak to your GP, specialist or Parkinson's nurse if you think you have these symptoms. They will be able to give you advice on what to do next.

Item text

We still don't fully understand why some people with Parkinson's get dementia. It isn't entirely possible to predict who it will affect, but there are factors that put certain groups of people at more risk.

Age is one example. It is rare that someone with Parkinson's under the age of 65 will develop dementia.

If someone with Parkinson's is experiencing hallucinations or delusions early on in their condition, this also suggests an increased risk of developing dementia.

If someone has been diagnosed with Parkinson's later in life, has had Parkinson's for a long period of time or has a family member with dementia, this can increase their risk of developing dementia.

Item text

A specialist will make a diagnosis based on the patient's symptoms, their medical history and the results of a medical examination.

There is no specific blood test for this condition, but tests of memory and thinking will help confirm what the problem is.

The specialist may also talk to the person's spouse or family members to find out how much of an impact issues such as memory difficulties are having on the person's day-to-day life.

It is important that other problems, such as severe depression, are excluded before the diagnosis of Parkinson's dementia can be considered.

Item text

As with Parkinson's, dementia can't be cured, but the symptoms can be treated.

If someone with Parkinson's has been diagnosed with dementia, the next step is for their specialist or Parkinson's nurse to have a look at what medication they're taking.

This is because some of the side effects of Parkinson's medication can make the symptoms of dementia worse. However, reducing the dose or withdrawing these drugs may mean that the Parkinson's symptoms aren't controlled as well as before.

For this reason, treating dementia often requires a compromise between managing the physical problems caused by Parkinson's and managing the issues caused by dementia.

Some people with Parkinson's may be suitable for dementia medication. This is likely to depend on the stage of dementia and the person's health. It may involve further memory and cognitive testing to see whether there is any change in their symptoms over time.

Medications called 'antipsychotics' or 'neuroleptics' might be considered to treat behavioural symptoms, such as sudden outbursts of anger.

Specialists usually avoid prescribing neuroleptics, but in some cases, if behavioural symptoms are becoming especially problematic, very low doses of these medications may have to be used.

If this medication is prescribed, the healthcare professional in charge of a person's care should monitor the situation carefully.

Any medication you take will need to be monitored. It's important to discuss the potential risks or side effects of any drug with your specialist so you can weigh these up against the problems you might have if you don't take it.

If you have any questions about medication for Parkinson's dementia, speak to your GP, specialist or Parkinson's nurse for more advice and information.

Item text

Dementia with Lewy bodies affects a person's memory, language, concentration and attention. It also affects their ability to reason, to recognise faces and to carry out simple actions.

People with this form of dementia commonly experience visual hallucinations, which can be quite vivid. These can happen early on in the condition.

They might also experience difficulty in judging distances and movements, which can cause them to fall over for no apparent reason.

Item text

There isn't a cure or specific treatment for dementia with Lewy bodies at the moment, but there are medications that some people may find effective.

Recent research suggests that some people may benefit from dementia medications called 'cholinesterase inhibitors'. But it's important to note that not all cholinesterase inhibitors are licensed for use in the UK.

Some people may respond well to Parkinson's medication, especially if they have Parkinson's-type symptoms, such as stiffness or rigidity. However, some side effects of these drugs can make the symptoms of dementia worse, especially confusion.

Since hallucinations and delusions are often associated with this condition, some doctors may recommend the use of 'antipsychotic' or 'neuroleptic' medications.

In general, these medications should be avoided, because they may make movement problems worse. But in some cases, if behavioural symptoms are becoming especially problematic, very low doses of these medications may have to be used.

If this medication is prescribed, the healthcare professionals in charge of a person's care should monitor the situation carefully.

If you have any questions about medication for dementia with Lewy bodies, speak to your GP, specialist or Parkinson's nurse for more advice and information.

Item text

If you are caring for someone with dementia, there are practical things you can do to help reduce their agitation or confusion and make life a bit easier.

  • Keep to a daily routine as much as you can, to help them remember when certain things, like meal times, will happen.
  • Try to use familiar objects and phrases, rather than new ones.
  • Avoid unfamiliar environments – these can be stressful.
  • Encourage someone with dementia to keep engaging and interacting with people. Hobbies are also a great way to stimulate their memory and thinking.

The Alzheimer's Society have lots more tips on understanding and supporting a person with dementia.

If someone becomes less able because of their dementia, it may be necessary for their family or friends to start helping with things such as shopping, housework or cooking.

If this is the case, the person may be able to apply for Attendance Allowance or Disability Living Allowance, which will help provide some financial support.

Item text

Medication can be helpful, but it's also useful for people to get treatment from a wide range of healthcare professionals.

Physiotherapists, occupational therapists, dietitians and speech and language therapists can all help someone with dementia and those supporting them.

You can be referred to these health professionals through your GP, specialist or Parkinson's nurse. In some areas, you might be able to refer yourself at the local hospital or community health clinic.

Local support

If you're caring for someone with dementia, consider support services such as day care, respite and home care. These services can give you a chance to have some time to yourself.

Parkinson's local advisers can help you access local support services.

Local groups

Parkinson's UK has local groups that offer support to anyone affected by Parkinson's and dementia.

The Alzheimer's Society has local branches that offer support to everyone affected by dementia.

These groups often provide various activities for people with dementia and also run carers' groups, which can introduce you and your carer to other people in similar circumstances.

Legal support

If you have been diagnosed with dementia, you may want to make important decisions about your finances or your Will, and what sort of healthcare and social care you'd like in the future.

You may also want to choose someone you trust to handle your affairs, and make this a legal agreement, in the form of a power of attorney.

Find out more about your rights and legal options

Download PDFs or order printed copies

Parkinson's dementia (PDF, 174KB)

Dementia with Lewy bodies (PDF, 172KB)

We know lots of people would rather have something in their hands to read rather than look at a screen, so you can order printed copies of our information by post, phone or email.

Give us your feedback

Did you find this content helpful?

Complete our short survey to give us your feedback.

Yes, this content was helpful

No, this content wasn't helpful

Last updated June 2011. We review all our information within 3 years. If you'd like to find out more about how we put our information together, including references and the sources of evidence we use, please contact us at [email protected].