2.2. Define the terms ‘delusion’ and ‘hallucination’

This. guide will help you answer 2.2. Define the terms ‘delusion’ and ‘hallucination’.

Many people living with dementia experience changes in how they see, understand, and interact with their surroundings. Among these changes, delusions and hallucinations can appear. They often cause distress, confusion, or anxiety, both for the person with dementia and those around them. Knowing what these terms mean, how they differ, and how they may present in dementia, helps workers provide compassionate and effective support.

What is a Delusion?

A delusion is a fixed, false belief. This belief is not based on fact or shared reality. A person with dementia might believe something that is not true. They will hold onto this belief despite evidence or logical arguments against it. Delusions are a kind of psychotic symptom, but they are not the same as having unusual ideas or being simply mistaken.

Delusions in dementia take on many forms. Some common types are:

• Paranoid delusions: Believing someone is out to harm, deceive, or steal.
• Jealous delusions: Thinking a partner is unfaithful without reason.
• Persecutory delusions: Feeling targeted or mistreated by others.
• Misidentification delusions: Not recognising familiar people or places and thinking they are imposters.

Features of Delusions in Dementia

• Belief is firm and often does not change even when shown evidence.
• The belief is not shared by others or based in reality.
• Delusions are not just simple misunderstandings or confusion.

Example of a Delusion

Mary, who has Alzheimer’s disease, insists her neighbour is stealing her jewellery. Her keys and rings are actually locked away safely, but Mary keeps accusing and is convinced her neighbour sneaks inside her flat.

Causes and Triggers

Delusions may appear because of:

• Memory loss: When a person cannot remember where they put something, they may believe someone stole it.
• Changes in the brain: The parts of the brain which help understand reality are damaged.
• Unfamiliar surroundings: When moved to a new place, confusion can make delusions more likely.

Effects on Daily Life

Delusions can make life harder for everyone involved. They can cause:

• Social withdrawal
• Suspicion of friends, family, or staff
• Distress and fear

The person may act based on these beliefs, leading to further confusion or even placing themselves or others at risk.

What is a Hallucination?

A hallucination is when a person hears, sees, smells, tastes or feels something that is not there. In other words, a person experiences something with one of their senses that others do not observe. Hallucinations are a sensory experience without an external cause.

Hallucinations are different from misinterpreting real things, which is common in dementia. For instance, confusing a dark coat on a chair for a person is not a hallucination, but misperception. A hallucination means the brain is creating the experience without anything to trigger it in reality.

Types of Hallucinations

Hallucinations can involve any of the five senses, but in dementia, the most common are:

• Visual hallucinations: Seeing people, animals or objects that are not there.
• Auditory hallucinations: Hearing voices, music or sounds that others do not hear.
• Olfactory hallucinations: Smelling things that are not present.
• Gustatory hallucinations: Tasting things that are not present.
• Tactile hallucinations: Feeling someone touching them or insects crawling on their skin when there are none.

Example of a Hallucination

Alan, who has Lewy body dementia, often sees children playing in his living room. There are no children present, but the scene seems real to Alan. He might speak to the children or make space for them. He sometimes gets upset when others do not see the children.

Causes and Triggers

Hallucinations in dementia are more common in certain types, such as dementia with Lewy bodies and Parkinson’s disease dementia. Other causes include:

• Medical conditions, like infections or pain
• Side effects from medication
• Poor lighting or sensory impairment (such as poor eyesight or hearing loss)

Disrupted brain chemicals and changes to sensory processing in the brain make hallucinations more likely.

Effects on Daily Life

Hallucinations may disturb or frighten someone. In some cases, they may be comforting or neutral, but often they cause:

• Fear or distress
• Difficulty sleeping
• Strain on relationships
• Disruption of normal activities

The person may react to the hallucination as if it is real, trying to move away, shout, or call for help.

Differences Between Delusions and Hallucinations

While both delusions and hallucinations are classed as symptoms of psychosis, they are not the same. Recognising the difference helps workers support people appropriately.

Key Points

• Delusions are about beliefs. Something the person thinks is true, without grounds in reality.
• Hallucinations are about perception. The person senses something that is not actually there.

You might hear a person talk about a hallucination (“There’s a dog barking in my room.”) or act based on a delusion (“My family is poisoning my food, so I won’t eat.”).

Students often mix up these terms, but the distinction is important for care planning and response.

Delusions in Dementia: More Detail

In dementia, delusions tend to be simple and often reflect the person’s history or fears. For instance, someone who worked as a teacher may believe their home is a school, and they are being inspected.

Common Features in Dementia

• Themes often repeat. For example, feeling unsafe, thinking valuables are stolen, or fearing abandonment.
• Linked to memory gaps. If a person cannot recall moving an object, they might believe someone took it.
• Sometimes mixed with real events. If a carer helps with finances, the person may insist money is missing.

Effects on Relationships

Delusions can strain relationships with family and friends. If a person insists, day after day, that someone is stealing, it may wear down trust on both sides. Workers need patience and understanding, and they should never argue or try to force someone out of a delusion.

Responding Effectively

• Stay calm and listen.
• Do not try to argue or force the person to accept your view.
• Provide comfort or reassurance.
• Redirect their attention if possible.
• Make the environment familiar and supportive.
• Keep records, so patterns can be spotted and shared with health professionals.

Hallucinations in Dementia: More Detail

Visual hallucinations are especially common in Lewy body dementia. The person often sees people, animals, or moving shapes that are not there. Auditory hallucinations — hearing voices or music — are rarer.

Observing Symptoms

Watch for signs that the person may be hallucinating:

• Speaking to someone who is not present.
• Looking at or reaching towards empty space.
• Appearing frightened by things others do not see.

When Hallucinations Occur

Hallucinations often occur late in the day or in poor lighting. Fatigue, stress, or overstimulation can trigger them. Some people are more prone when they are ill or in pain.

Impact on Quality of Life

Hallucinations may deeply affect the person’s mood and behaviour. Repeated distressing hallucinations may lead to anxiety, aggression, or withdrawal. Some people, though, accept them calmly if they are not frightening.

Responding Effectively

• Offer reassurance and support.
• Avoid denying what the person experiences.
• Check for sources of stress, pain, or infection.
• Make the environment as calm, safe, and well-lit as possible.
• Share observations with health professionals if symptoms change or worsen.

Why These Definitions Matter in Care

Knowing what delusions and hallucinations are enables the worker to:

• Recognise symptoms early.
• Respond compassionately without confrontation.
• Protect the safety and dignity of people with dementia.
• Work with others to review medication or physical health if symptoms appear suddenly.
• Plan activities and routines which minimise stress or confusion.

Misunderstanding these terms can lead to poor support, increased distress, and even harm. Care workers must use both empathy and clear understanding of these concepts.

Supporting People with Delusions and Hallucinations

Approaches used in care depend on knowing the difference between a belief and a perception.

Practical Advice

• For delusions: Use distraction, change the topic, or support the person to check a fact (such as where keys are kept). Never force confrontation.
• For hallucinations: Redirect attention, create a calm environment, and check sensory aids like glasses and hearing aids are working.

Not every delusion or hallucination needs medical treatment. The worker should focus on comfort, reassurance, and keeping the person safe. If new or severe symptoms appear, involving the GP or community mental health team is wise.

Involving Family and Friends

Help relatives know that these experiences are part of the illness, not deliberate behaviour. Offer advice on calm responses and avoid blaming. Including family in the care plan helps everyone feel more secure.

Final Thoughts

Delusions and hallucinations are two of the most challenging symptoms for people with dementia. Delusions are false beliefs; hallucinations are false perceptions. Knowing the difference means support workers can respond safely, calmly, and compassionately. Recognising these symptoms early can help avoid distress, maintain relationships, and promote the best possible quality of life for the person with dementia and everyone involved in their care. Understanding these terms is a key part of working in health and social care.