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Mental Capacity Act


The Mental Capacity Act (2005) is a law that protects and empowers people aged 16 and over who do not have the ability to make decisions for themselves. It also provides guidance to support people who need to make decisions on behalf of someone else.

The Act covers a wide range of decision making, from complex decisions such as significant financial matters, social care, medical treatment, and wider welfare matters, to simpler decisions like deciding what to eat or what clothing to wear.

The Act is underpinned by five statutory principles that are legal requirements.

Principle 1: A person must be assumed to have capacity unless it is established that they lack capacity.

The presumption of capacity means that it is assumed that everyone has capacity until proved otherwise. The burden of proving the person lacks capacity lies with the person assessing their capacity. Do not assume that someone cannot make a capacitated decision just because they have a particular condition or disability.

However, whilst the presumption of capacity is a fundamental principle it should not be used to avoid responsibility to assess capacity if it is reasonably suspected a person may lack capacity to make a specific decision, especially if this is likely to lead to serious consequences.

Principle 2: A person is not to be treated as unable to make a decision unless all practicable steps have been taken without success.

This means that all practical steps should be taken to help the person make the decision themselves. It is important to consider factors that might help them to participate in the assessment such as the time of day, the location, the form of communication used, any others who may need to be present to support them, and that the person has been provided with all the relevant, or salient, information.

Even if the person is assessed as lacking capacity they should still be involved as far as possible in the decision-making process.

Principle 3: A person is not to be treated as unable to make a decision merely because he/she makes an unwise decision.

This means that people must not be treated as unable to make a decision merely because they make an unwise decision. The focus of assessing a person’s capacity needs to be based on how they make a decision rather than the decision itself.

In complex mental capacity act assessments this may need to include consideration of both the person’s decisional capacity (their ability to state what they will do) as well as their executive capacity (their ability to actually execute/carry this out) using observational and historical evidence.

Principle 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 or her best interests.

If a person has been assessed as lacking capacity regarding a specific decision then any action taken, or decision made for, or on behalf of that person must be made in their best interests.

This should incorporate any information known about their previous preferences, interests or views.

Principle 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.

If a decision is made, or action undertaken, on behalf of a person who does not have mental capacity it should be the least restrictive option of person’s rights and freedoms. Other less restrictive options should be considered and undertaken if at all possible.

These principles clearly identify that whilst professionals should always start with assuming the person has mental capacity there may be doubt about the person’s ability to make a capacitated decision due to a range of factors including illness, brain injury, a learning disability, mental health problems or the effects of drug or alcohol.

When considering mental capacity, and whether a mental capacity assessment may need to be undertaken, there is a two-stage test that must be evidenced:

  • Does the person have an impairment of the mind or brain or is there some sort of disturbance affecting the way their mind or brain works (whether the impairment or disturbance is temporary or permanent)?
  • If so, does the impairment or disturbance mean that the person is unable to make the decision in question at the time it needs to be made?


Once this two-stage test has been satisfied the Mental Capacity Act states that a person is said to lack capacity if they are assessed as being unable to do one or more of the following things:

  • Understand the information given to them
  • Retain that information long enough to be able to make a decision
  • Weigh up the information available to make a decision
  • Communicate their decision.

It is important to remember that capacity can fluctuate and that any mental capacity act assessment that is undertaken is time and decision specific. The person only needs to be able to retain the relevant, or salient, information for long enough to weigh-up their options and communicate their decision. The Mental Capacity Act states ‘the fact that a person is able to retain the information relevant to a decision for a short period only does not prevent him from being regarded as able to make the decision.’

Independent Advocacy

Independent Mental Capacity Advocates (IMCA’s) were established in the Mental Capacity Act and help people who lack the capacity to make specific important decisions: including making decisions about where they live and about serious medical treatment options.

IMCAs are mainly instructed to represent people where there is no one independent, such as a family member or friend, able to represent the person. They are a legal safeguard to ensure that in these situations people are supported to express their wishes and feelings, weigh up their options, and make decisions.

The importance of independent advocacy continued with the implementation of the Care Act and the statutory duty for local authorities to ensure people are involved in assessment, care and support planning, and review and safeguarding processes.

If it appears that a person has care and support needs, then a judgement must be made as to whether that person has substantial difficulty in being involved and if there is an appropriate individual to support them. If they ae judged as having substantial difficulty and there is not an appropriate individual to support them an independent advocate must be appointed.

Deprivation of Liberty Safeguards (DOLS)

The Deprivation of Liberty Safeguards (DoLS) are part of the Mental Capacity Act 2005. They are intended to ensure that when someone lacks the mental capacity to consent to care or treatment the least restrictive approach is taken, and the person’s freedom is not inappropriately restricted.

A deprivation of liberty occurs when;

  • a person is under continuous supervision and control in a care home or hospital, and
  • is not free to leave, and
  • the person lacks capacity to consent to these arrangements.

The safeguards set out a procedure for hospitals and care homes to follow to obtain an authorisation if they believe it is in the person’s best interests to deprive a person them of their liberty. It is then the role of Brighton and Hove Health and Adult Social Care to arrange for assessments to authorise that the deprivation of liberty is in the person’s best interests. Without this authorisation any deprivation of liberty will be unlawful.

Whether someone is deprived of their liberty depends on the person’s specific circumstances. A large restriction may sometimes in itself be a deprivation of liberty or sometimes a number of small restrictions added together will amount to a deprivation of liberty. What needs to be assessed is the amount of control that the care home or hospital has over the person.


It is important to remember that the Mental Capacity Act applies to all professions working with people who may lack capacity to make decisions. This includes doctors, nurses, social workers, care assistants and support workers.


Below are a range of resources that are available to enable both professionals and the public to understand more about the Mental Capacity Act.

The code of practice gives guidance to people who:

  • work with people who can’t make decisions for themselves
  • care for people who can’t make decisions for themselves

It says what you must do when you act or make decisions on behalf of people who can’t act or make those decisions for themselves.

Mental Capacity Act Code of Practice – GOV.UK (

Bournemouth University have produced a Mental Capacity toolkit that can be found here.

Mental Capacity Toolkit

Tri.x have produced a Mental Capacity Act resource and practice toolkit.

Mental Capacity Act 2005 Resource and Practice Toolkit (

The National Institute for Clinical Excellence have produced guidance to help health and social care professionals support people to make their own decisions where they have the capacity to do so and to ensure that if they lack capacity they are at the centre of the decision-making process.

Overview | Decision-making and mental capacity | Guidance | NICE

This free online course from SCIE explores the Mental Capacity Act, including best interests’ decision-making, and how to support people to make their own decisions.

The course is for everyone who looks after or cares for someone, for example, doctors, nurses, care assistants, social workers, and family members.

Mental Capacity Act (MCA): e-Learning course | SCIE

If you are concerned about an adult at risk of abuse or neglect you can report a safeguarding concern at



or phone 01273 295555.

If you feel that somebody is at immediate risk of harm and that it is an emergency, call 999.