Assessing the mental capacity of a person with dementia

The Mental Capacity Act gives guidance on assessing mental capacity – when it should be done and who should do it. This can be used when assessing the mental capacity of a person with dementia.

1. Dementia and the Mental Capacity Act 2005
2. You are here: Assessing the mental capacity of a person with dementia
3. Making decisions for a person with dementia who lacks mental capacity
4. Planning ahead using the Mental Capacity Act
5. Mental Capacity Act – other resources

When should mental capacity be assessed in a person with dementia?

You must always assume that a person is able to make a decision for themselves, until it is proved that they can’t.

A person’s capacity may be questioned if there is doubt about whether they can make a particular decision. This could happen if:

• the person’s behaviour or circumstances are making those around them doubt whether the person has capacity to make a particular decision
• a professional says they have doubts about the person’s ability to make the decision – this could be a social worker or the person’s GP
• the person has previously been unable to make a decision for themselves.

To work out whether a person has capacity to make a decision, the law says you must do a test (often called an assessment) to find out whether they have the ability to make the particular decision at the particular time.

Before the person is tested, they should be given as much help as possible to make the decision for themselves. Those who are supporting the person to make the decision should find the most helpful way to communicate with the person. This may mean:

• trying to explain the information to them in a different way
• helping them to understand the ideas that are involved in making the decision
• breaking down information into small chunks.

Not all decisions need to be made immediately. It is sometimes possible to delay a decision until a person has capacity to make it. However, this won’t be possible for every decision.

The person with dementia should be offered different ways of communicating their wishes and decisions. Better communication can make it easier to meet the needs of the person with dementia.

Who can assess mental capacity in a person with dementia?

In general, whoever is with the person when a decision is being made will assess their capacity. However, this will differ depending on the decision that needs to be made – for example:

• Everyday decisions (such as what someone will eat or wear) – whoever is with them at the time can assess the person’s capacity to make the decision. This is likely to be the person’s family member, carer or care worker.
• More complicated decisions (such as where someone will live or decisions about treatment) – a professional will assess the person’s capacity to make the decision.

In general, family members and carers know the person with dementia best. They can often tell when the person is or is not able to make a decision. When a person has dementia, it’s likely that they will have to do this more often as the person's condition progresses.

If the decision is complicated, the person's carer or family members can consult a professional, such as a solicitor or a health or social care professional. Note that certain professionals may charge for advice.

Whether it is someone close to the person or a professional, they must firmly believe that the person with dementia can’t make their own decision before taking action to make the decision for them. The steps below can help with this assessment.

How is mental capacity assessed in a person with dementia?

If you need to decide whether a person has the mental capacity to make a specific decision, follow the steps below.

Always try to use your knowledge of the person to help you decide. You can also ask other people for advice – such as the person’s GP, community nurse or social worker.