False beliefs and delusions in dementia

At times, many of us have beliefs that may not be true. For example, someone might believe their neighbour doesn’t like them, even if there’s no evidence. But we usually have some control over our beliefs, so they don’t have an undue influence on our lives. 

When someone has dementia, however, they may lose the ability to think logically about whether their beliefs are true. These false beliefs, also called delusions, can become very powerful and upsetting. 

Common false beliefs and delusions include: 

• thinking that someone is trying to steal from them 
• thinking that someone is trying to harm them 
• believing that their partner is being unfaithful 
• thinking they’re living in the past – for example, that they still go to school or have a job 

Dementia can also affect people’s memory. They might forget where they left something and believe it has been stolen. Or they might forget that their partner has gone shopping and think they are with another man or woman. 

Delirium – a sudden onset of confusion, often with an underlying physical cause such as an infection – is another possible cause of false beliefs and delusions. If you notice a sudden change in someone’s behaviour or thinking, or if they appear more confused than usual, make an urgent appointment with their GP. 

• claiming that someone is stealing from them or trying to harm them 
• hiding possessions to keep them safe
• phoning the police frequently 
• refusing to open the door or answer the phone 
• talking in whispers, and saying things such as: “They can hear us” 
• trying to carry out activities they used to do, like going to school or work 
• mistaking people’s identities  
• believing they’re in a different place 
• reliving past traumas or events 

It’s important to remember that sometimes, the claims the person with dementia is making may be true, and someone could be stealing from them or taking advantage of their vulnerability. This needs to be carefully checked before you conclude that what they are saying is a false belief or delusion. 

However, there are ways to help a person who is experiencing false beliefs or delusions.  

• try to explain what’s happening without challenging or correcting them. You could say something like: “The thought that someone has stolen your purse must be very distressing. Let’s see if we can find it in case it was accidently misplaced”   
• speak in a calm, reassuring way to ease their distress
• 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

It’s also a good idea to arrange a medical check-up to rule out other physical or mental health problems, and to review any medication that may be causing false beliefs and delusions.  

• agree on places to keep important items like keys, handbag and wallet, so you know where to look first if they think something has disappeared 
• keep spares of essentials that might get misplaced, such as glasses or keys 
• make sure they have regular eye and hearing tests – difficulties with sight or hearing can increase confusion 
• encourage them to eat and drink regularly
• try to keep to a routine and limit changes to their environment 
• keep photographs of them and close family/friends at different life stages around the house, to help them recognise the time they’re living in