Decision-making capacity in dementia

The two-stage mental capacity assessment

Decisions cannot be made for a person with dementia unless there is evidence that they can't make the decision themselves. But how can we assess a person's capacity to make a decision? The Mental Capacity Act sets out two things that have to be checked before it can be decided that a person cannot make a decision for themselves:

Always start from the assumption that the person has the capacity to make the decision in question.

First principle of Mental Capacity Act

This is called the two-stage mental capacity assessment.

Who decides whether a person can make their own decisions?

The person who is expected to do the mental capacity assessment is the person who might have to do something in the person's best interests (for more on this, see the feature on 'Making decisions in a person's best interests' in this section) if the person lacks capacity. Here are some examples:

As you can see, any member of the care team – or the wider community – may have to make an assessment about a person's mental capacity.

What is expected of care workers?

Care workers don't have to be experts in working out whether a person with dementia can make a particular decision. It is OK to have a 'reasonable belief'.

But how do you establish what is a reasonable belief? If you know a person has dementia, you need to think about whether they can understand what the risks are. For example, if the person wants to go out for a walk alone, can they understand the risks of traffic and remember the way home? Or if a person wants to make a cup of tea, are they able to understand the risk from boiling water?

If the decision is minor – say, deciding between tea and coffee or what music to listen to – then most people will be able to make their own decision. If you think a person with dementia is unable to make a particular decision, you should be able to give reasons for this. It is good practice to write these in their care plan. Here are some examples to show what this would look like:

Mrs Singh is unable to make decisions about having a wash. This is because her dementia means she doesn't understand the risks of not washing when doubly incontinent.

Mr Charles has dementia and diabetes. He is unable to make decisions about what he eats. This is because he does not understand the risks of poor sugar control.

But it is important to remember that people can make unwise decisions – even in relation to their own – if they understand the consequences.

A capacity dilemma: helping with medication

Often care workers are expected to help people with dementia to take their medication. As a care worker, you need to know if the person is making their own decisions about agreeing to take the medication or if it is being given to them in their 'best interests' (for more on this, see the feature 'Making decisions in a person's best interests' in this section).

The doctor prescribing the medication should have decided this already and let the staff supporting the person know. This should be written in the care plan.

The care staff wouldn't need to do a capacity assessment each time they supported the person, but should be alert for any evidence that the person might have improved their ability to consent to taking the medication. If this happens, make sure the doctor knows that you think the person's capacity has improved.

Where the person lacks capacity, it would be OK to encourage the person to take their medication if they are gently resisting it. But it wouldn't be good practice to ignore any evident distress about taking the medication, or for the staff member to hide the medication in food or to use a form of restraint so the person takes the medication. This can only happen if it is written in the care plan and agreed by a proper best interests process as being in the person's best interests.


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Available downloads:

  • Activity: Capacity to make decisions
  • What the research says: Making decisions