Understanding changes in behaviour

Understanding changes in behaviour

Dementia affects people in different ways and changes in the behaviour or emotional state of a person living with dementia are common. These changes can sometimes be stressful for the person, and for families and carers.

    Why behaviour may change?

    There are many reasons why a person’s behaviour may change.

    It may be caused by:

    • an inability to communicate as effectively as they once did
    • changes in the brain caused by dementia, affecting memory, mood and behaviour
    • changes in the environment, such as temperature, noise, crowds, light, large rooms or open areas
    • changes in abilities, such as when a familiar task becomes too complex
    • changes in health, due to medication, not feeling well, or an underlying illness such as an infection or pain.

    Dementia sometimes makes it harder for a person to say what they need or to understand what people are asking of them. Understanding the causes of their behaviour can help you find ways to respond if this occurs.

    Seek advice

    Always discuss concerns about changes in behaviour with their doctor. A medical examination can help identify any medical conditions or side effects of medication that may be causing the changes. The doctor can also be a good source of information and advice.

    Responding to changes in behaviour often requires trial and error. Always remember that the behaviour is not deliberate.

    Anger and aggression are often directed at family members and carers because they are closest. The behaviour is out of the person’s control and they may feel frightened. They may need reassurance, even if it does not appear that way.

    Tips to minimise changes in behaviour

    • Provide a calm, relaxing environment and follow a daily routine.
    • Keep the person’s environment familiar. Strange situations or unfamiliar people may cause confusion and stress.
    • Stay quiet or neutral if you are told something that seems wrong or untrue. Try and avoid correcting the person.
    • Do not rush the person. Allow plenty of time for communication and daily activities.

    Tips to respond to behaviour changes

    • Avoid punishment. The person may not remember the event and be unable to learn from it.
    • Stay calm.
    • Speak slowly, in a quiet and reassuring voice.
    • Try to redirect a conversation or task to something that is more enjoyable.


    Aggression is often an expression of anger, fear or frustration. Aggressive behaviour can be physical, such as hitting out. It can also be verbal, like shouting.

    Tips to minimise the risk of aggressive behaviour

    • Aggression can sometimes be a response to an unmet want or need. Try to anticipate their needs.
    • When offering assistance, approach the person slowly and so they can see you. Explain what is going to happen in short, clear statements. For example, saying “I’m going to help you take your coat off” may avoid aggression as a self-defence response.
    • Regular physical activity and exercise may help prevent some behavioural changes.

    Tips to respond to aggressive behaviour

    • Usually, it is best to avoid touch.
    • Avoid restraint, leading the person away or approaching from behind.
    • Try leaving the person alone and give them time to settle.
    • Call a friend or neighbour for support.


    Some people living with dementia overreact to seemingly small incidents. This is called a catastrophic reaction. They may:

    • scream
    • shout
    • make unreasonable accusations
    • become agitated or fixed in their ways
    • cry or laugh uncontrollably or inappropriately
    • become withdrawn.

    This behaviour can appear very quickly and can make family and carers feel frightened.

    Overreacting can be caused by:

    • stress due to the unmet demands of a situation
    • frustration caused by misinterpreted messages or feeling rushed, embarrassed or incompetent.
    • another underlying illness, infection or pain.

    It may be a passing phase, decreasing as the condition progresses. Or it may go on for some time.

    Tips to minimise the risk of overreacting behaviour

    • Keep a diary of these behaviours. It may help you figure out a pattern or trigger.
    • You can use this information to assist with reducing the risk or responding to future incidents.


    People living with dementia can appear intent on searching for something they believe is missing. They may also hoard things for safekeeping.

    There are many causes of hoarding behaviours:

    • Isolation. When the person is left alone or feels neglected, they may become completely focused on themselves. The need to hoard is a common response.
    • Memories. Events in the present can trigger negative memories of the past.
    • Loss. Losing friends, family, a meaningful role in life, an income and a reliable memory can increase a person’s need to hoard.
    • Fear of being robbed. They may hide something precious, forget where it has been hidden and then blame someone for stealing it.

    Tips to try for hoarding behaviour

    • Learn their usual hiding places and look there first for missing items.
    • Provide a drawer of odds and ends to sort out. This can satisfy the need to be busy.
    • Provide a rummage box to support the safekeeping of treasured items and support memory and reminiscing prompts.
    • Keep the environment familiar. This helps the person find their way around and reduces the need for hoarding.

    Repetitive behaviour

    A person living with dementia may repeat an action, question or statement many times. This may be due to their inability to remember what they have already said and done.

    They may also become clingy and shadow you, even following you to the toilet, for fear of losing sight of you. These behaviours can be upsetting and irritating.

    Tips to respond to repetitive behaviour

    • If an explanation does not help, try distraction, with a walk, food or favourite activity.
    • It may help to acknowledge the feelings underneath a repeated question or statement. For example, “What am I doing today?” may mean a feeling of uncertainty. If someone repeatedly asks what they should be doing, it may help to give them a written list of upcoming appointments.
    • Answer repeated questions as if you are being asked for the first time. The person cannot remember they have asked you, so avoid telling them you have already answered their question.
    • Repetitive movements may be reduced by providing something else to do with their hands, such as a soft ball to squeeze or clothes to fold.

    Where to get help

    If changes in behaviour are causing distress for the person, or the behaviour is having an impact on you:

    • Discuss with the person’s doctor your concerns about changes in behaviour.

    • Call the National Dementia Helpline on 1800 100 500 to learn about support services and education programs, including carer support groups, counselling, and services and programs to assist you to understand and respond to changes and maintain your health and wellbeing.

    • Call the Dementia Behaviour Management Advisory Service on 1800 699 799. They support people living with dementia who experience changes in behaviour that impact their care or the carer.

    Additional reading and resources

    For information, advice, common sense approaches and practical strategies on the topics most commonly raised about dementia, read our Help sheets

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