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Mental Capacity Act (MCA) practice guidance


Part 6 How to assess capacity

[MCA section 2-3; Code of Practice chapter 4]

What is capacity?

The MCA defines a lack of capacity as:

‘a person lacks capacity in relation to a matter if at the material time he is unable to make a decision for himself in relation to the matter because of an impairment of, or a disturbance in the functioning of, the mind or brain.’

(MCA section 2(1); Code of Practice 4.3).

Capacity relates to a particular decision at a particular time. In the past, someone’s ‘capacity’ was assessed in an overarching way and a general statement was made that ‘Mrs X lacks capacity’ – and then all decisions were made for Mrs X. The MCA makes this practice unlawful.

The test

The MCA introduces a two step process of assessing someone’s capacity.

Step 1: The diagnostic test
The first step is known as the diagnostic test. This means looking for evidence that the person is suffering from; ‘an impairment of, or a disturbance in, the functioning of the mind or brain.’ This is a very wide gateway which would include any form of:

  • learning disability
  • mental illness, including dementia
  • brain injury, including stroke damage
  • neurological damage,
  • intoxication – from chronic drug use to a couple of glasses of wine
  • temporary confusional state caused by infection, illness, tiredness or pain

(Code of Practice 4.12).

Most people at some time will be covered by this diagnostic test and some people will always come within it. This doesn’t necessarily mean that they lack capacity to make a particular decision at a particular point in time.

Step 2: The decision-specific functional test
This test considers whether the person can make this decision at this time. This is because you need different understanding to make different decisions. For instance, someone may not have capacity to manage their money, but may be able to make a decision about their medical treatment; they may not be able to make a decision about where they live but may be able to decide how they spend their time.

The first step of the functional test is to be clear what the decision is that needs to be made. If there is a complex situation there may need to be several capacity assessments concerning different decisions.

The assessor then needs to establish if the person can:

  • understand the information relevant to the decision
  • retain information relevant to the decision
  • use or weigh the information as part of the process of making the decision
  • communicate their decision.

(MCA section 3; Code of Practice 4.14)

If the person is unable to do any one of these four things, they lack capacity to make this decision at this time.

Make sure the person has access to all the relevant information about the decision and is helped to consider all the subtleties of the decision they need to make

The person only needs to be able to retain information long enough to use it to make the decision – there isn’t a requirement for longer term memory.

To be able to use or weigh the information someone needs to be able to consider conflicting information: for example: ‘I’ve always wanted to stay in my own home, but if I fall I might be on the floor all night before anyone finds me’. They have to be able to understand the risks and consider the consequences of their decision

The ability to communicate the decision is by any means – sign language or body language would be acceptable. (Code of Practice 4.15-25)

When should I assess?

If there is a possibility of someone recovering their capacity to make the decision – if they lack capacity because of an infection causing confusion – then the decision should wait, if it is safe to do so. Some decisions can’t wait; for example a decision about the medical treatment which might enable someone to regain their capacity. However, if at all possible, decisions should be delayed until the person has the best chance of making their own decision. (Code of Practice 4.27; 5.25-5.27)

Your duty to enable someone to make their own decision

Following Principle 2 it is your responsibility to do everything you can to give a person the best chance of being able to make their own decision.

Make sure you:

  • are clear about the decision
  • are clear about the information the person needs to understand and consider – someone making a decision about living independently would need information about the care package they might receive, how long between visits, how extensive their support would be, the risks of living independently, the options for living in care and so on
  • are able to communicate this information in a way most likely to enable the person to understand
  • have thought about how the person is best able to communicate – do you need an interpreter, help from audiology department, a speech and language therapist or other specialist?
  • consider the best time of day to do the assessment and the best location
  • have thought about whether the person should have someone with them – a family member may help them to feel more comfortable or may inhibit what they say
  • repeat the information if necessary or visit the person more than once.

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