Hallucinations and delusions

Some people with dementia may experience hallucinations or delusions. Of course not everyone with dementia will be affected and not everyone who has these problems has dementia. This advice sheet looks at ways of handling these experiences.

People with dementia sometimes experience hallucinations. They may see, hear, smell, taste or feel things which are not really there. Hallucinations involving sight or hearing are the most common.

The reaction of the person with dementia to the hallucination may vary.

• They may realise that their imagination is playing tricks with them and pay no attention to the hallucination. They may find it difficult to decide whether or not the hallucination is real. In such instances they may find it reassuring if you go with them to look at where they saw an imaginary object, or to check the room where they thought they heard voices or other noises. You can then confirm that nothing is there.
• As the dementia becomes more severe some people may become convinced that what they are seeing or hearing is real. This can be very frightening. It is worth trying to let them know that, although you cannot share their experience, you do understand that it is distressing for them. There is no point in arguing about whether or not what they are seeing is real.

They may realise that their imagination is playing tricks with them and pay not attention to the hallucination.

Hallucinations are less likely to occur when the person is occupied or interested in what is going on around them.

If the person with dementia is distressed by their hallucinations or if the hallucinations are persistent speak to the GP. Medication can sometimes be prescribed.

Visual Hallucinations

Visual hallucinations are the most common type of hallucination in dementia. The person may see people, animals or other objects. Sometimes the hallucinations involve quite complicated scenes or bizarre situations.

Visual hallucinations can start with misinterpretations. The person may think they see faces or objects in swirling patterns on fabrics or in the shadows in a room, for instance.

Many people with dementia who experience visual hallucinations only experience them occasionally. Moreover they often only last a few seconds. However, sometimes they are more persistent and troublesome. Possible causes of visual hallucinations include:

Illness: Hallucinations can result from physical illness such as infections or the side-effects of some types of medication. Advice from a doctor is usually necessary to help rule out these possibilities.

Eyesight: Visual hallucinations may be due to poor eyesight. Poor eyesight cannot always be improved but you should:

• arrange regular eye checks and encourage the person to wear their glasses if they need them discuss with the GP whether cataracts should be removed if poor sight is due to cataracts
• check that any glasses worn are clean and of the right strength
• make sure that there is good lighting

Changes in the brain: People sometimes experience hallucinations because of changes that are occurring in their brain as the dementia progresses.

Visual hallucinations often occur in people who have Lewy body dementia. In this type of dementia the person usually has a mixture of the symptoms found in Alzheimer's and Parkinson's disease.

People who have persistent visual hallucinations together with stiffness and slowing of movement, or marked fluctuations in their abilities, are likely to have Lewy body dementia. If this is the case, anti-psychotic medication, which is sometimes given for troublesome hallucinations, can make any stiffness worse. It should therefore only be prescribed in low doses, if at all, and regularly reviewed.

Auditory Hallucinations

Auditory hallucinations occur when people hear voices or other noises although nothing is there. As with visual hallucinations it is important to rule out possible causes such as physical illness and the side-effects of medication. It is also worth checking the person's hearing and making sure their hearing aid is working properly, if they have one.

One sign that the person may be having hallucinations involving voices is when they talk to themselves and pause, as though waiting for someone else to finish what they are saying, before continuing. However, it is important to remember that not everyone who talks to themselves is having hallucinations.

Shouting at people who are not there also suggests the possibility of hallucinations. People are less likely to hear imaginary sounds while they are talking to someone real so company can help.

Delusions

People with dementia may sometimes become rather suspicious, usually due to their failing memory. They may accuse someone of stealing from them, when something has been mislaid for example. However, they are often reassured when the object is found.

With some people this suspicion goes much further and they may develop distorted ideas about what is actually happening. They may become convinced that other people want to harm them, for example, and no amount of evidence to the contrary will persuade them otherwise. This kind of belief is called a delusion and can be very distressing both for the person with dementia and for those close to them.

Some of the delusions that people with dementia have include:

• their partner is being unfaithful
• their partner or close relative has been replaced by an impostor who closely resembles them
• their home is not their own
• their food is being poisoned
• their neighbours are spying on them.

People with dementia usually have these odd ideas because of the changes that are occurring in their brain. However, sometimes these ideas may also follow on from hallucinations. There is often little point in arguing with the person as this only causes further distress.

Try to reassure the person that you are on their side and want to help them. Distract them with other activities.

Ask for advice from a specialist community nurse. Medication can sometimes be helpful, particularly if the person is becoming aggressive. Ask the GP.

Explaining Behaviour

It is important to explain any unusual beliefs or behaviour to all those in contact with the person with dementia so that they understand the situation and can reassure or distract the person as appropriate.

The Society would like to thank Dr Rupert McShane, Department of Psychiatry, University of Oxford for help in preparing this advice sheet.

Page Text supplied by The Alzheimer's Disease Society of Great Britain