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Mood and behaviour changes

A family with the daughter looking at something her mother has painted
How dementia changes behaviour

Dementia can change the way someone feels and behaves. These changes might be subtle or dramatic. They might come and go, or persist. They might lead to the person feeling, saying and doing things that are very out of character.

These changes aren’t deliberate, but they can be upsetting for the person with dementia, and for the people close to them.

There are many reasons why a person’s behaviour may change, including:

  • physical changes in the brain caused by dementia
  • inability to communicate as well as they used to
  • changes in their environment, like temperature, noise, crowds, light, large rooms or open areas
  • changes in abilities like vision, hearing or thinking, that can make ordinary tasks overwhelming and stressful
  • changes in health, due to medication side-effects, not feeling well, or an underlying illness
  • physical discomfort, like hunger, tiredness, dehydration, being too cold or warm, constipation or the need to go to the toilet
  • emotional or physical needs that aren’t being met.

Kinds of mood and behaviour change

Every person experiences dementia differently, but common mood and behaviour changes include:

What you can do

If you notice changes in the mood or behaviour of someone close to you with dementia, it can help to start keeping a diary or log of what’s happening. It can help you better understand what’s triggering these changes and what works to help them. Make a note of:

  • what specifically happened: how they changed, what they did or said
  • when it happened
  • who was involved
  • what was happening around them just before it happened
  • who was affected
  • how you and other people responded and whether it helped.

Go over the events you’ve listed regularly to look for patterns, causes, and useful strategies to help. You can also show your diary to your doctor or specialist for advice.

Tips to minimise changes in behaviour

  • Provide a calm, relaxing environment.
  • Keep the person’s environment familiar and their routine regular.
  • Stay neutral if they tell you something that seems wrong or untrue. Try to avoid correcting them.
  • Allow plenty of time for communication and daily activities.
  • Avoid punishment. The person may not remember the event and be unable to learn from it.
  • Stay as calm as you can, especially when they can’t.
  • Speak slowly, in a quiet and reassuring voice.
  • Try to distract them with a conversation or activity they enjoy.

Responding to changed moods and behaviours is a process of trial and error. There’s no one solution that works for everyone, every time. But the more you notice, and the more things you try, the better equipped you’ll be to help them and yourself.

It’s okay to take care of your own health and happiness. If you're struggling as someone who cares for a person with dementia, contact the free, confidential National Dementia Helpline on 1800 100 500, any time of the day or night, for information, advice and support.

Responding to changes in behaviour

Help with changed mood and behaviour

If changes in the mood or behaviour of someone close to you with dementia are causing them or you distress, there is help available:

Dementia expert webinar: changed behaviours, with Scientia Professor Henry Brodaty AO
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Last updated
23 July 2024