What is the Mental Capacity Act?

Louise Petty

August 12, 2024

5 min read

It’s vital that all health and social care professionals understand what the Mental Capacity Act requires of them in order to ensure patients are respected, protected and empowered to make their own decisions. In this article, we’ll look at what and who is covered by the Mental Capacity Act, the main principles of the Act and how to ensure you’re always acting in a person’s best interests when making decisions on their behalf.

What is the Mental Capacity Act?

The Mental Capacity Act 2005 (MCA) is a UK law designed to empower and protect people in care who lack the capacity to make their own decisions. For example, choosing anything from what to eat and what to wear to deciding which care home to move to or whether to have surgery or new medication.

‘Mental capacity’ refers to a person’s ability to make decisions, whether in day-to-day life or one-off, more serious decisions about their care, treatment or finances. A person with good mental capacity is able to make choices, understand information about the choices and communicate their decisions. Someone who lacks mental capacity is unable to do these things, often as a result of illness, injury, a mental health condition or medication.

The Mental Capacity Act has a two-stage test to determine capacity:

Does the person have an impairment of their mind or brain, whether as a result of an illness or external factors, such as alcohol or drug use?
Does the impairment mean the person is unable to make a specific decision when they need to? People can lack capacity to make some decisions but have capacity to make others. Their mental capacity can also change over time.

In all situations, a person should be enabled to make their own decisions. They’re also allowed to nominate someone else to make decisions on their behalf if they become unable in the future, and this person should always be consulted if you need to make a choice on behalf of a patient.

If a person lacks capacity to make decisions, and you need to make a decision for them, then it must always be in their best interests. Section 4 of the Mental Capacity Act contains a checklist that outlines what you need to consider to ensure you’re acting in a person’s best interests:

Consider a person’s past and present wishes, feelings, beliefs and values.
Consider the specific type of condition, illness or injury the person has, how long it’s likely to last for and the person’s age.
Consider if the person is likely to regain capacity to make the decision in the future. If so, postpone the decision until that point (wherever possible).
Encourage the person to take part in the decision, doing whatever you can to help them be involved and to communicate in a way that works for them.
Consider the views of the person’s family, carers or nominated person/s.
Never make assumptions about a person that could be discriminatory, i.e decisions based on their age, disability, race or sex.

In specific cases, decisions may need to be made on behalf of a person which restrict their personal freedom. This is known as a deprivation of liberty and can only happen in very specific circumstances. If a deprivation of liberty is required, the care provider must first apply to their local authority for legal authorisation, as depriving someone of their freedom can infringe on a person’s basic human rights.

Who Does the Mental Capacity Act Apply to?

Everyone who works or cares for someone who may lack capacity to make decisions must comply with the Mental Capacity Act. This applies to all types of job roles in health and social care, including nurses, doctors, therapists, assistants, support workers, social workers and many more.

The Mental Capacity Act itself applies to all people aged 16 or over and who may lack capacity to make decisions for one or more reasons. This includes people with:

An illness, such as dementia or stroke.
A brain injury.
A learning disability.
A mental health condition.
Unconsciousness, such as from anaesthetic or an accident.

These conditions don’t necessarily mean a person lacks the capacity to make all decisions. In some instances, they may be unable to make specific decisions but are able to decide on others. For example, they’re able to choose their clothing but unable to choose their care environment. The key is to never assume someone lacks capacity and never to make all decisions on behalf of a person.

The Mental Capacity Act defines someone as ‘unable to make a decision’ if they cannot:

Understand the information relevant to the decision.
Retain information to make a decision.
Use or weigh up information to make a decision.
Communicate their decision in any way.

5 Principles of the Mental Capacity Act

There are five principles of the Mental Capacity Act that must be considered before any action is taken on behalf of a person. The five principles are:

Always assume a person has the capacity to make a decision, unless it’s proved otherwise.
Always help people to make their own decisions wherever possible. Support the person in all ways you can to make the choice themselves.
Never assume someone doesn’t have capacity to make a decision, just because you think their choice is wrong or unwise.
All decisions made on a person’s behalf must be in their best interests.
Always opt for the least restrictive alternative if a decision needs to be made on someone’s behalf. Decisions must not restrict someone’s basic rights or freedoms and, where there are multiple options, the least restrictive option must be chosen.

If you work in health and social care, then an understanding of the Mental Capacity Act is an important part of your role. People who lack capacity must be fully supported to make their own decisions where possible, and you should only ever make choices on their behalf if everything else has been tried first. As a caregiver, acting in a person’s best interests is one of the most important things you can do, and this includes empowering them to make their own decisions.