Skip to content

The Mental Capacity Act (MCA) 2005

The Mental Capacity Act 2005, covering England and Wales, provides a statutory framework for people who lack capacity to make decisions for themselves, or who have capacity and want to make preparations for a time when they may lack capacity in the future. It sets out who can take decisions, in which situations, and how they should go about this.

The Mental Capacity Act 2005 affects people who can’t make decisions for themselves, perhaps because of:

  • a learning disability;
  • dementia;
  • a mental health problem;
  • a head injury or a stroke;
  • a drug, alcohol or substance addiction; or
  • an acute illness, or the treatment for it.

All major decisions where a person lacks mental capacity are covered by the Act, from how their finances are managed to whether or not they have medical treatment.

The MCA Code of Practice (pdf, 1.7Mb) provides guidance to anyone who is working with and/ or caring for adults who may lack capacity to make particular decisions.

The Code has statutory force, which means that certain categories of people have a legal duty to have regard to it when working with or caring for adults who may lack capacity to make decisions for themselves.

The 5 principles of the Mental Capacity Act

  1. A person must be assumed to have capacity unless it is established that they lack capacity.
  2. 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. A person is not to be treated as unable to make a decision merely because he makes an unwise decision.
  4. 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. 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 freedom of action.

Assessing capacity

Assessments of capacity should be time and decision specific.

To help determine if a person lacks capacity to make particular decisions, the Act sets out a two-stage test of capacity.

Stage 1 - Is there an impairment of or disturbance in the functioning of a person’s mind or brain? If so,

Stage 2 - Is the impairment or disturbance sufficient that the person lacks the capacity to make a particular decision?

The MCA says that a person is unable to make their own decision if they cannot do one or more of the following:

  • understand information given to them;
  • retain that information long enough to be able to make the decision;
  • weigh up the information available to make the decision; and
  • communicate their decision – this could be by talking, using sign language or even simple muscle movements such as blinking an eye or squeezing a hand.

People must be given all practical and appropriate support to help them make the decision for themselves.

Decision Making

If a person has been assessed as lacking capacity then any action taken, or any decision made for or on behalf of that person, must be made in his or her best interests (principle 4). The person who has to make the decision is known as the ‘decision-maker’ and normally will be the carer responsible for the day-to-day care, or a professional such as a doctor, nurse or social worker where decisions about treatment, care arrangements or accommodation need to be made.

The Deprivation of Liberty Safeguards is an amendment to the Mental Capacity Act 2005.

The Act introduces new roles and responsibilities

The Act introduces a new form of Power of Attorney which allows people over the age of 18 to formally appoint one or more people to look after their health, welfare and/or finances, if at some time in the future they lack capacity to make those decisions.

Further information is available from DirectGov: What is lasting powers of Attorney

Independent Mental Capacity Advocates (IMCAs) are a statutory safeguard for people who lack capacity to make some important decisions. This includes decisions about where the person lives and serious medical treatment when the person does not have family or friends who can represent them. Further information about IMCA is available from POhWER Advocacy

The Act creates statutory rules with clear safeguards so that people may make a decision in advance to refuse treatment if they should lack capacity in the future. Further Information is available from DirectGov: Your right to refuse future medical treatment

The Act also creates a new criminal offence of ill treatment or wilful neglect of a person who lacks capacity. Further information on MCA 2005 is available from The Department of Health (DoH)