Expert opinion - The Mental Capacity Act 2005

This legislation has important implications for oncology and palliative medicine. By Dr Michael Ball

The Mental Capacity Act 2005 provides a statutory framework in England and Wales to empower and protect adults aged 16 or over who lack capacity to make their own decisions. Similar legislation exists in Scotland, in the form of the Adults with Incapacity (Scotland) Act 2000.

The Mental Capacity Act was introduced in April and October 2007 and is now fully in force (see box 1). Its main provisions, covering capacity, best interests, advance decisions, independent mental capacity advocates (IMCAs), lasting powers of attorney (LPAs) and a new Court of Protection, have important implications for oncology and palliative medicine.


The Act is underpinned by five key principles

  • A presumption of capacity Every adult has the right to make his or her own decisions and must be assumed to have capacity to do so unless it is proved otherwise
  • Individuals supported to make their own decisions A person must be given all practicable help before anybody treats them as being unable to make their own decisions
  • Unwise decisions Just because an individual makes what might be seen as an unwise decision, they should not be treated as lacking capacity to make that decision
  • Best interests An action carried out or decision made under the Act for, or on behalf of, a person who lacks capacity must be done in their best interests
  • Least restrictive option Anything done for, or on behalf of, a person who lacks capacity should be the least restrictive of their basic rights and freedoms

The Act is supported by a code of practice, which provides guidance and information about how the Act works in practice and should therefore be the first point of reference for anybody interested in finding out more. The code has statutory force, which means that there is a legal duty to have regard to it when working with, or caring for, adults who may lack capacity to make decisions. A copy of the code can be downloaded from

Many of the provisions of the Act, particularly in relation to capacity, best interests and advance decisions, are based on common law principles. The Act clarifies and improves on these, but also introduces some important new areas of law, for example, IMCAs, LPAs and the Court of Protection. It also includes a new criminal offence of wilful neglect or ill-treatment of people without capacity.

Assessing capacity
The Act provides a two-stage test for assessing capacity, very similar to the previous common law test. Is there an impairment of, or disturbance in the functioning of, the person's mind or brain? The impairment or disturbance of the mind or brain may occur in a wide range of situations; for example, people who are affected by the symptoms of drug or alcohol misuse, mental illness, dementia, learning disabilities or the long-term effects of brain damage.

Is the impairment of disturbance such that the person is unable to make a decision? Patients are unable to do this if they cannot understand and retain the information, use or weigh it as part of the decision-making process, or communicate the decision by any means. Temporary factors, such as acute illness, severe pain, the effect of medication or distress after a death or shock, may also affect somebody's ability to make a decision.

The two-stage test is decision-specific. Nobody can be labelled 'incapable' as a result of a particular condition or diagnosis.

Best interests
If the two-stage test for assessing capacity is applied and the patient is found to lack capacity, the previous common law principle of applying best interests is described in the Act. This provides a non-exhaustive checklist that must be taken into account when assessing what is in the patient's best interests.

Healthcare professionals should not discriminate when making best interest decisions, for example, when the patient is very old. They should instead consider all of the relevant circumstances when making a decision.

Find out what the patient would have taken into account if they were making the decision themselves, for example, their religious views. If possible, delay the decision if there is any likelihood that the patient may soon regain capacity and be able to make the decision. Enable and encourage participation, even though the patient lacks capacity.

There should be special considerations for life-sustaining treatments. In this case, the person making the best interests decision must not be motivated in any way by a desire to bring about the patient's death. They should not make assumptions about the patient's quality of life. Take into account the person's past and present wishes and feelings, beliefs and values, and the views of other people, such as close friends and relatives.

Advance decisions
An advance decision (previously called advance declaration or living will) means a decision made by somebody when they have capacity to refuse treatment once they have lost that capacity. These decisions were already in force under common law, but the Act clarifies the law and makes an important change.

Advance decisions can be made orally and they can be altered or withdrawn orally. The person making the decision must be over 18 years old. The treatment being refused must be specified; for example, a statement giving a general desire not to be treated is not enough to make the decision valid.

The main change in the Act is that refusal of life-sustaining treatment must be in writing, containing a statement that it applies even if life is at risk, signed by the patient and witnessed.

It is the responsibility of the person making the advance decision to make sure their decision will be drawn to the attention of the healthcare professional when needed. But if somebody tells a healthcare professional that an advance decision exists for a patient who now lacks capacity, the professional should make reasonable efforts to find out about the decision, for example, by asking relatives, looking in medical records or contacting the patient's GP.

Independent mental capacity advocates
The IMCA service has been set up under the Act to protect particularly vulnerable adults who lack capacity. IMCAs are a group of independent people who have been trained to assess and discuss best interests decisions with the person making those decisions, for example, the patient's consultant.

An IMCA must be instructed and consulted for patients lacking capacity who have no family or friends to support them whenever an NHS body is proposing to provide serious medical treatment, or an NHS body or local authority is proposing to arrange or change accommodation in hospital or a care home, and the person will stay in hospital longer than 28 days or in a care home for more than eight weeks.

The code of practice gives examples of serious medical treatment, including chemotherapy and surgery for cancer, ECT, therapeutic sterilisation, major surgery, major amputations, treatment resulting in loss of hearing or sight, withholding or stopping artificial nutrition and hydration, and termination of pregnancy.

The Act gives IMCAs various rights, including meeting the patient, reviewing the records and asking for a second opinion. While the final decision-maker does not have to comply with the IMCA's recommendations, they must record how they took their views into account.

Lasting powers of attorney
An enduring power of attorney (EPA) is a document that allows a patient to authorise one or more persons to make decisions concerning their assets and financial affairs, normally in the event that the patient loses capacity.

EPAs still have legal force if they were drawn up before October 2007, but after that, the Act replaced them with LPAs. An LPA, as well as conferring financial decision-making powers on another person, allows for health and social care powers to be handed over, normally to a relative or close friend (called the attorney). The Act allows for more than one attorney to be appointed if the patient wishes.

For health and social care decision-making, the attorney may only act when the patient who has given the powers has lost capacity to do so. If an attorney has been appointed, a clinician does not make the best interests decisions on behalf of the patient. Instead, the attorney is consulted and has to be obeyed, provided the decisions are in the patient's best interests. It should be noted, however, that the attorney has no power to consent to, or refuse, life-sustaining treatment, unless the LPA expressly authorises it.

The LPA must be signed by the person who is giving the powers, the attorney(s) and an independent third party, who must verify that the person giving the powers understands the purpose of the LPA and there is no fraud. The LPA must be drawn up on the correct form and registered with a new body, the Office of the Public Guardian


Mrs Joshi has never trusted doctors and prefers to rely on alternative therapies. She saw her father undergoing invasive treatment for cancer, so she is clear that she would refuse such treatment herself. She is diagnosed with cancer and discusses her wishes with her husband.

She knows her husband would respect her wishes if he ever had to make a decision about her treatment. She establishes a lasting power of attorney, appointing him as her attorney, with authority to make all of her health and social care decisions.

Mrs Joshi includes a specific statement authorising him to consent to or refuse life-sustaining treatment. He will then be able to consider her views and make decisions about treatment in her best interests if she later lacks the capacity to make these decisions herself.

Court of Protection
In October 2007, the new Court of Protection replaced the old court of the same name, which only dealt with financial affairs. Health and social care, which were previously dealt with in the High Court, are now included.

In difficult or complicated cases, or where there has been disagreement, for example, with the family, instead of the clinician making the decision on capacity or best interests, the new court can be asked to make a declaration on the matter.

Some decisions are so serious that in each case, an application should be made to the court for a declaration that the proposed action is lawful before it is taken.

Cases involving any of the following should be brought before the court - decisions about the proposed withholding or withdrawal of artificial nutrition and hydration from patients in a permanent vegetative state, cases involving organ or bone marrow donation by a person who lacks capacity to consent, cases involving the proposed non-therapeutic sterilisation of a person who lacks capacity to consent, for example, for contraceptive purposes, or all other cases where there is doubt or dispute about whether a particular treatment will be in a patient's best interests.

In conclusion, the most prominent change in the Act is the introduction of IMCAs and LPAs. As familiarity with the Act increases, healthcare professionals will find themselves having greater contact with both.

- Dr Michael Ball is a doctor and lawyer at Barts and the London NHS Trust


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