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1.6 Mental Capacity


The Mental Capacity Act (MCA) 2005 provides a statutory framework to empower and protect some of the most vulnerable people in society. It makes it clear who can take decisions, in which situations and how they should go about this in respect of people who lack Capacity to make particular decisions for themselves.


Mental Capacity Act Code of Practice

Mental Capacity Act: Easy Read

SCIE Library of MCA Resources


  1. Mental Capacity Principles
  2. Assessing Capacity
  3. Best Interests
  4. Independent Mental Capacity Advocates
  5. IMCAs in Safeguarding
  6. IMCAs in Care Reviews
  7. Lasting Power of Attorney
  8. Advance Decisions
  9. Written Statements About WIshes and Feelings
  10. Court of Protection

1. Mental Capacity Act Principles

There are five principles of the Mental Capacity Act 2005 (MCA). These are:

  1. Presumption of Capacity: A person must be assumed to have Capacity unless it is established that he lacks Capacity;
  2. Must offer any practicable support: A person is not to be treated as unable to make a decision unless all practicable steps to help him to do so have been taken without success;
  3. Unwise/Lack of Capacity: A person is not to be treated as unable to make a decision merely because he makes an unwise decision;
  4. The Best Interest Principle: An act done, or decision made, under this Act for or on behalf of a person who lacks Capacity must be done, or made, in his Best Interests;
  5. The Least Restrictive Principle: Before the act is done, or the decision is made, regard must be had to whether the purpose for which it is needed can be as effectively achieved in a way that is less restrictive of the person’s rights and freedoms.

2. Assessing Capacity

The Mental Capacity Act specifies that “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”.

A person is not able to make a decision if he / she is assessed as unable to do any one of the following:

  • Understand the information relevant to the decision; or
  • Retain that information; or
  • Use or weigh that information as part of the process of making the decision; or
  • Communicate their decision (whether by talking, using sign language or any other means).

Click here to view Mental Capacity Act: Tips for Assessing Capacity.

3. Best Interests

An act done, or decision made, under the MCA for or on behalf of a person who lacks Capacity must be done, or made, in his or her Best Interests.

The Act provides protection from liability where there is a reasonable belief that the person lacks Capacity to Consent and a reasonable belief that the decision is in the person’s Best Interest.

It is not necessary to hold a meeting each time a Best Interest decision needs to be made.

 It is important to consider who is the best person to make the Best Interest decision. It will usually be the person who is carrying out the decision (and therefore requires protection from liability).

The decision-maker is the person who is providing or organising the care. For example, for:

  • A surgery – the surgeon or member of the surgical team;
  • A flu injection – the community nurse administering the flu injection or the GP who prescribed it;
  • A shower/bath – the care worker.

So, a local authority worker will usually be the decision-maker for the:

  • Decision to accept or refuse a community care assessment;
  • Decision to accept or refuse a local authority funded support package;
  • Decision of whether to move into local authority funded residential care.

The decision-maker must consider the Best Interest checklist, as below, including the views of the person and others who are close to the person. A record should be made showing how a decision was reached and detailing the factors that were taken into account.

3.1 Best Interest Checklist

Working out someone’s Best Interests cannot be based simply on age, appearance, condition or behaviour:

  • All relevant circumstances should be considered;
  • Every effort should be made to encourage and enable the person to take part in making the decision;
  • If there is a chance the person will regain the Capacity, then it may be possible to put off the decision;
  • The person’s past and present wishes and feelings, beliefs and values should be taken into account;
  • The views of other people who are close to the person who lacks Capacity should be considered.

A Best Interest decision maker should seek consensus with others involved with the person. The decision-maker does not have power to overrule others.

The MCA Code of Practice suggests that holding a meeting or conference may be a useful to resolve disputes or disagreements allow family members to air conflicting views, have a multi-disciplinary discussion about what treatment is in a person’s Best Interest.

If there is still a disagreement after the meeting, an interim plan can be made. The person who disagrees should be given advice on how to challenge the decision. If the dispute is about admission to residential care or hospital, deprivation of liberty should be considered. Relatives can use the Complaints Procedure especially if the person is unable to do so.

Click here to view Best Interests Guidance.

4. Independent Mental Capacity Advocates

Independent Mental Capacity Advocates (IMCA) provide statutory advocacy introduced by the Mental Capacity Act 2005 (MCA). The MCA gives some people who lack Capacity a right to receive support from an IMCA.

IMCAs support and represent people who have been assessed as lacking Capacity to make specific decisions in their lives.

4.1 When to refer for an IMCA

Click here to view When Should I Request an IMCA? Flowchart.

5. IMCAs in Safeguarding

Click here to view IMCAs in Safeguarding: Policy and Guidance.

6. IMCAs in Care Reviews

Click here to view IMCAs in Care Reviews: Policy and Practice.

7. Lasting Power of Attorney

The Mental Capacity Act sets out guidance for appointing Lasting Powers of Attorney. A person can appoint a person, or persons, to make certain decisions on their behalf in the event that they later lack mental Capacity to make those decisions themselves.

Lasting Power of Attorney can be granted for financial and / or health and welfare decisions.

They must be registered with the Office of the Public Guardian before use. If a person indicates they are acting as power of attorney for another person who lacks Capacity, it is best to ask to see the documentation to confirm what type of power of attorney the person has, and whether it is registered. If there are any concerns about how the Power of Attorney is fulfilling their role, these can be raised with the Office of the Public Guardian.

Click here to view information about Lasting Power of Attorney.

8. Advance Decisions

The Mental Capacity Act allows adults with Capacity to set out a refusal of specified medical treatment for a time when they might lack the Capacity to Consent or refuse that treatment. Advance decisions may be written or verbal, but must state precisely what treatment is to be refused, in medical or everyday language. Advance decisions to refuse life-sustaining treatment must be in writing, signed and witnessed and must include a statement saying that it applies even if life is at risk.           

Click here to view further information about Advance Decisions to Refuse Treatment.

9. Written Statements About Wishes and Feelings

People may also make an advance statement about their preferred care or treatment for a future time when they may lack Capacity to make that decision. However, such statements about preferred treatment are not binding in the same way as advance decisions to refuse treatment. They must be considered in Best Interest decision-making.

It is not possible to make a binding advance decision to refuse care. Advance statements about care preferences including living arrangements must be considered as part of Best Interest decision-making. If a person has put their care preferences in writing, the decision maker must consider them carefully and record their reasons for not following the written wishes including the reasons why it was not in the person’s Best Interest.

10. Court of Protection

The Court of Protection is a specialist court dealing with decision-making for adults who may lack Capacity to make specific decisions for themselves.

Local authorities, health bodies, services users, relatives and other concerned parties may seek legal advice about making an application to the court of protection for an order determining treatment, residence, care or contact arrangements.

This will usually only be the case where it is not possible to reach agreement on what is in a person’s Best Interest.

There are some decisions that only the court can make on behalf of a person lacking Capacity. These are found in the Chapter 8, MCA Code of Practice.

Some parties must ask permission of the Court of Protection before making an application. People who do not need permission include:

  • A person who lacks, or is alleged to lack, Capacity in relation to a specific decision;
  • The donor of the Lasting Power of Attorney an application relates to – or their attorney;
  • A deputy who has been appointed by the court to act for the person concerned;
  • A person appointed by a supervisory body as a relevant person’s representative.

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