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Mental capacity and decision making

As dementia progresses, many people need help making decisions about their health, care, finances and living arrangements. We explain what mental capacity is and how to support someone who has lost capacity.

‘Mental capacity’ is a legal term that refers to someone’s ability to make decisions about their care and treatment.

Some decisions are small, like what to wear or what to buy in the supermarket.

Others are big, like when to move into a care home or whether they would want to receive lifesaving medical treatment.

Many people with dementia will eventually lose the capacity to make decisions about their health, care or finances.

To have capacity, a person must be able to:

  • understand the information relevant to the decision they are making
  • retain that information for long enough to make the decision
  • weigh up the information as part of their decision-making process
  • communicate that decision to others

Capacity may come and go – for example, the person may temporarily lose capacity if they have an infection causing delirium (an intense state of confusion), but regain it once they are better.

They might also have capacity to make some decisions but not others.

It should always be assumed that a person has capacity to make a decision unless evidence clearly proves otherwise.

If there is doubt about a person’s capacity, a trained health or social care professional can carry out a Mental Capacity Assessment. They must follow the Mental Capacity Act Code of Practice and consider:

  1. Does the person have an impairment of their mind or brain?
  2. Does the impairment mean they cannot make a specific decision when they need to?

A Mental Capacity Assessment only extends to the particular decision being made at that time – for instance, whether a person should move into a care home.

If another decision then has to be made, for example about managing their finances, another Mental Capacity Assessment will be needed.

There are two types of document which can help with planning for the future in the event that someone loses capacity.

  • An Advance Care Plan: a document in which the person sets out their wishes for their future medical and social care
  • A lasting power of attorney (LPA): a document that appoints an ‘attorney’ – that is, a person who can make decisions on someone’s behalf when they have lost capacity. There are two types: a health and welfare LPA and a property and financial affairs LPA

If possible, it is very important to establish an Advance Care Plan (ACP) and LPA soon after diagnosis while the person with dementia has capacity.

This will ensure they can make their future wishes known, and make the process of managing their care and finances less complicated for family and friends.

When a person with dementia can no longer make informed decisions for themselves, their family and health and social care staff may have to make a ‘best interest decision’.

This is especially important for big decisions, such as selling the person’s home or considering a move into residential care.

A Best Interests Meeting should be arranged to establish what is in the person’s best interests. This should involve:

  • the person with dementia (as far as possible)
  • their family
  • health and social care professionals
  • anyone else who is actively involved in the person’s life

Ideally, you should all discuss the decision together, and aim to come to a consensus about the person’s best interests.

When making a best interest decision, you should consider:

  • the person’s current wishes and views, or wishes and views they have expressed previously
  • their culture and beliefs
  • whether they have an Advance Care Plan and/or LPA, and what these say

Any decisions made should be the least restrictive option possible.

For example, if the person wishes to go for regular walks but are too vulnerable to go out alone, the best interest decision would be for someone to accompany them, rather than deciding they cannot go out.

Deprivation of liberty is when someone’s freedom is taken away, for example if:

  • they are under continuous supervision/control
  • they lack the capacity to consent to their care arrangements
  • there are limitations on where they can go eg they cannot leave a hospital or care home

Deprivation of Liberty Safeguards (DoLS) are a set of six checks that are used to ensure that if a person is deprived of liberty, it is done in the least restrictive way possible and in their best interests.

A Mental Capacity Assessment would first need to be done to establish whether the person has capacity, followed by a Best Interests Meeting.

DoLS apply in England and Wales only.

To speak to a dementia specialist Admiral Nurse about capacity, decision-making or any other aspect of dementia, please call our free Dementia Helpline on 0800 888 6678 (Monday-Friday 9am-9pm, Saturday and Sunday 9 am-5pm), email or you can book a virtual Admiral Nurse Clinic appointment by phone or video call.

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Our free, confidential Dementia Helpline is staffed by our dementia specialist Admiral Nurses who provide information, advice and support with any aspect of dementia.

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