False beliefs and delusions in dementia

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We understand the world through our senses. The five basic senses can be affected by dementia: hearing, sight, smell, taste and touch. These senses collect information and send it to the brain, which uses it to make sense of the world around us.

For some people living with dementia, their brain misinterprets the information from their senses. This can lead to them holding false beliefs and delusions about the world around them. These false beliefs or ‘different realities’ can be very distressing for the person with dementia – and the people caring for them. A common example is believing that someone is stealing from them. It might not be true, but to the person experiencing this belief, it’s real and trying to explain that it isn’t real, might increase the person’s distress.

In this leaflet, we’ll look at what we mean by false beliefs and delusions, suggest why this might be happening, and think about ways to prevent or manage them.

What are false beliefs and delusions?

A person’s beliefs are the basis for how they view the world. We start forming what we believe as children and continue to build upon it throughout our lives. Examples could include someone’s religious or political beliefs. But there are ‘life lessons’ that people can pick up that can have a negative influence on their lives, for instance, beliefs such as: “Don’t trust people; they’ll always let you down.”

Our beliefs are personal to us, and as such, it’s possible that all of us might have thoughts and beliefs at some time that are ‘false’. Someone might believe that their neighbour doesn’t like them when there’s no evidence to support this. But people with normal cognitive function have some control over how their beliefs affect them and don’t usually allow them to become a negative influence in their life.

When someone has dementia, they may lose the ability to moderate their thoughts or keep them in check, and this is when false beliefs can become a problem.

Delusions are fixed ideas that aren’t based on reality. But to a person with dementia, they feel true, and the person’s mind can’t be changed by appealing to reason. As a result of their dementia, people may misplace or lose things, have difficulty in recognising people or their environment or may appear to be living in the past. To help them make sense of this ‘different reality’, those with dementia may believe that people are stealing their money or other possessions, or think there are people trying to mislead or harm them. One common accusation is that the person’s partner is being unfaithful, when there is no evidence that this is the case. These different realities or delusions can make the person with dementia feel frightened, which can lead to them resisting their friend’s and family’s attempts to care for them.

Why does it happen?

Dementia can cause people to have difficulty with recognising people, places and things, particularly in later stages. Dementia can also affect people’s memory, so that they might not remember where they left something or why they’re in a particular place.

These problems with recognition and memory can lead to suspicion, paranoia and false beliefs. They might think that ‘strange people’ are in their house; they might find themselves unexpectedly in a place they don’t recognise. Objects might seem to disappear from the place they were sure they were in. Conversations they’re having might not make sense to them. People seek to understand these confusing and worrying events, and might do so by blaming someone or something else.

Delirium can also lead to the appearance or increase in false beliefs or different realities. If there is a sudden change in someone’s behaviour or thinking, or they appear much more confused than usual, it could be due to delirium. This should be investigated by a doctor immediately (please see our leaflet on Causes and treatment for delirium).

How can I recognise when a person with dementia is experiencing delusions?

The person with dementia might:

  • make accusations that someone is stealing from them or harming them in some way
  • hide possessions around the house to keep them safe
  • phone the police frequently
  • refuse to open the door or take calls from people who they are suspicious of
  • talk in whispers in the house and say things such as: “They can hear us”
  • constantly lose things
  • think they’re younger than they are, and want to carry out roles they used to do, such as going to school or work
  • mistake identities of people
  • believe they’re in a different place
  • re-live past traumas or events

Practical tips on preventing some false beliefs and delusions

If possible, in the early stages of dementia, decide with the person, on places to keep essential items such as keys, handbag and money, so you can establish a routine and locate important things more easily.

You could also:

  • keep spares of important items that might get misplaced, like glasses or keys
  • make sure the person with dementia has regular hearing and sight tests
  • monitor the person with dementia for any signs of infection, constipation or other physical ill health, and seek a medical appointment quickly
  • look out for possible side effects if there has been a change in medication. Occasionally some medications can cause or exacerbate false beliefs or delusions
  • check the person with dementia is eating and drinking sufficiently
  • try to keep to a routine and limit changes to the person’s environment
  • keep photographs of them and close family/friends through different life stages around the house, to help them recognise the present time

Tips for managing false beliefs and delusions as they happen

  • Try to recognise and understand that to the person, this belief or reality is real and so are the emotions they feel as a result
  • Provide explanations and reassurance to the person without challenging or correcting the false belief or delusion
  • Respond to any fear, distress and anger by speaking in a calm and reassuring way. You could say something like: “The thought that someone is stealing from you must be very distressing. Let’s have a look around to see if we can find it in case it was accidently misplaced.” This acknowledges what the person is feeling and offers them a solution
  • Try to establish what caused the false belief or delusion and if possible prevent this becoming an issue again, for example, put their wallet or purse in a previously agreed, obvious, place
  • Try to involve the person in doing something they enjoy as a way of distracting them
  • If these strategies are not working, try just ‘going along’ with the person until they’re calmer and/or have moved onto a different topic
  • Arrange for a medical check-up to rule out the possibility of other physical or mental health problems, or issues with medication
  • Sometimes, where delusions are causing a major problem, a trial of a drug treatment may be appropriate
  • Recognise that if a family member, friend or carer is falsely accused of stealing or harming the person, they’re likely to feel distressed and may also need to be reassured. You could pass on a copy of this leaflet so they can understand what is happening and try some of the suggested techniques

Please remember that sometimes the claims the person with dementia is making may be right and someone could be stealing from them or taking advantage of their vulnerability. This needs to be carefully checked before jumping to the conclusion that what they are saying is a false belief or delusion. If you are concerned, you can contact Dementia UK’s Admiral Nurse Dementia Helpline on 0800 888 6678

Sources of support

Dementia UK leaflet on Changes in perception and hallucinations in dementia dementiauk.org/changes-in-perception

Dementia UK leaflet on Life story work

Dementia UK leaflet on Things to try when someone with dementia stops recognising you

False beliefs and delusions in dementia

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