Mental capacity


  • The 5 principles
  • Mental capacity assessments
  • Understanding information about the decision to be made
  • Is the decision in the persons best Interest?
  • What else do you need to consider?
  • Deprivation of Liberty: all person’s aged 16 and over
  • The Mental Capacity (Amendment) Act 2019
  • Other resources
  • Mental capacity means being able to make your own decisions. The Mental Capacity (Amendment) Act 2019 (MCA) aims to ensure that individuals participate as fully as possible in all decisions relating to them.

    It protects those who cannot make their own decisions about a particular matter for any reason whether temporary or permanent. It applies to people aged 16 years and over. A person’s mental capacity (ability) may vary over time and/or may depend on the type of decision that needs to be made.

    Anyone caring for or supporting an individual may assess capacity where they are the person proposing the intervention. The assessment must be specific to the decision that needs to be made, at the time the decision needs to be made. Mental capacity is therefore time and decision specific, not a fixed notion of a person’s overall competence.

    For health and care interventions and medical decisions, informed consent is always needed for treatment or examination; the doctor or healthcare professional who is proposing the intervention will have to assure themselves whether or not the person has capacity (ability) to give (or withhold) informed consent to the proposed intervention. Therefore ‘Consent’ and ‘Capacity’ can be viewed as two sides of the same coin.

    The 5 principles of the Mental Capacity Act


    1. A presumption of capacity
    2. Individuals are supported to make their own decision
    3. Unwise decisions
    4. Best interests
    5. Less restrictive option

    These are as follows:

    1. Presumption of capacity

    Start off by thinking that everyone can make their own decisions. Ask yourself, “does it appear that this person can make this decision?” Are you assured that they have understood? If not, apply principle 2 (below).

    2. Being supported to make their own decisions

    Give the person all the support you can to help them make decisions. To justify an intervention, you must show that you have taken all practicable and realistic steps to help them to make the decision, such as explaining the risks and benefits to help them to make an informed choice and decide whether to give or withhold their consent. This might also include using a different form of communication, treating a medical condition which may be affecting the persons capacity (such as a urinary tract infection), or a structured learning programme to improve the persons capacity.

    3. Unwise decisions do not necessarily mean lack of capacity

    Keep in mind that just because the person has made a choice in one area of their lives that seems to you unwise it doesn’t automatically mean that they lack capacity in a different choice at a different time.

    Remember: one person’s seemingly unwise decision is another person’s calculated risk. However, if you have tried all practicable steps to support them to make the choice themselves, they are unlikely to regain capacity and/or the decision cannot be delayed, and support has not been successful then apply principles 4 and 5 (below).

    The following link is to a helpful article; How do I know if it’s an unwise mental capacity decision? Beth Yolland-Jones | 14 Oct 2022.

    4. Decisions must be taken in the person’s best interests

    Anytime someone does something, or decides for someone who lacks capacity, it must be in the person’s best interests. The MCA provides a non-exhaustive checklist of factors that decision-makers must work through in deciding what is in a person’s best interests:

    Next of Kin (NoK) - remember, the role of ‘next of kin’ alone does not confer consent giving rights. The following link is to a very helpful guidance regarding NoK:

    Next of Kin: Understanding decision making authorities.
    PDF, 397kb, 4 pages

    Any best interest decision must be made in the person’s best interest not solely the best interest of services or family or professionals.

    5. Carefully consider actions to ensure the less restrictive option is taken

    The decision maker should always consider whether it is possible to provide the intervention or support in a less restrictive way. Is there a less restrictive and or intrusive option that will achieve the desired outcome?

    Mental capacity assessments

    An assessment of a person’s capacity must be based on their ability to make a specific decision at the time it needs to be made (with support if necessary), and not their ability to make decisions in general. A person may be able to make decisions about some issues but not about others. For example, a person may be able to manage a small financial allowance to cover their day-to-day expenditure but not be able to make more complex decisions about their financial affairs.

    Therefore, the starting point must always be to assume that a person has the capacity (ability) to make a specific decision, unless it can be established that they lack capacity. The person does not have to ‘prove’ they have capacity.

    A person’s capacity must always be assessed explicitly in terms of their capacity to make a specific decision at the time it needs to be made.

    You must treat everyone equally. You cannot decide that someone lacks capacity based upon assumptions regarding age, appearance, about their condition or behaviour. For example, any scars, features linked to Down’s syndrome, muscle spasms caused by cerebral palsy, as well as aspects of appearance like skin colour, tattoos and body piercings, or the way people choose to dress (including religious dress).

    The person must be placed at the very heart of the decision-making process. When considering a person’s capacity, it is important that steps are taken to try and support the person to make their own decision, and this can include asking the following questions:

    Anyone assessing someone’s capacity to make a decision will need to apply the *test in the Mental Capacity Act

    *Whilst it is often known as the ‘capacity test’, it is not a medical test, but rather a legal test.

    It can be broken down into three questions:

    1. The first question is, “Is the person able to make the decision (with support if required)?” If so, no further steps in the assessment process are needed.

    2. If they cannot, the second question you must ask is "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?" (It doesn’t matter whether the impairment or disturbance is temporary or permanent).

    Many factors can affect a person’s capacity such as:

    3. If so, the final question you must answer is: “Is the person’s inability to make the decision because of the impairment or disturbance?” The impairment or disturbance must be the reason the person cannot make the decision.

    What proof of lack of capacity does the Act require?

    Anybody who claims that a person lacks capacity should be able to show on the balance of probabilities, that the person lacks capacity to make a particular decision, at the time it needs to be made. This means being able to show that it is more likely that the person lacks the capacity to make the decision in question at the time it needs to be made. The person does not have to 'prove' that they have capacity.

    Assessing ability to make a decision

    As stated earlier, this can be broken down into three questions:

    1. Is the person unable to make the decision?
    2. Is there an impairment or disturbance in the functioning of the person’s mind or brain?
    3. Is the person’s inability to make the decision because of the impairment or disturbance?

    Another useful way to look at assessing a person’s ability to make a decision is to ask yourself:

    “Can the person make this decision at the time it needs to be made?”
    If the answer is ‘Yes’, that is the end of the process and you respect what they have decided, even if the decision appears to be ‘unwise’ such as withholding consent to medical treatment. Where the answer is either ‘no’ or ‘don’t know’ ask yourself;
    “What appropriate help and support to make the decision should be given?”
    This could be through providing information in a simpler way, such as using easier words or pictures, trying at different times of the day or when they are in better health or having a family member, friend or an independent person or advocate to help them express their choice.

    A person is unable to make a decision if they cannot:

    1. Understand information about the decision to be made (the Act calls this ‘relevant information’) including understanding the likely consequences of making, or not making the decision.
    2. Retain that information in their mind (long enough to make the decision).
    3. Weigh or use that information as part of the decision-making process, or
    4. Communicate their decision (by any means).

    The first three should be applied together, ideally in the form of conversation. If a person cannot do any of these three things, they will be judged as unable to make the decision, at the time it needs to be made.

    The fourth only applies in situations where people cannot communicate their decision in any way, whether by talking, using sign language or any other means.

    Ask yourself:

    The following 30 minute film shows all of the steps in action: Using the Mental Capacity Act in the community.

    In conclusion, ask yourself:

    1. “Does the person have general understanding of what decision they need to make and why they need to make it?”
    2. “Does the person have a general understanding of the likely consequences of making, or not making, this decision, or deciding one way or another?”

    A conclusion that a person lacks capacity to make a particular decision must be based upon the test as per MCA 2005, and not on any other test a health or social care professional may use for other tasks. For instance:

    A common area of difficulty can be where a person gives coherent answers to questions, but it is clear from their actions that they are unable to give effect to their decision. This is sometimes called an impairment in their executive function. If the person cannot understand (and/or use and weigh) the fact that there is a mismatch between what they say and what they do when required to act, it can be said that they lack capacity to make the decision in question.

    However, this conclusion can only properly be reached when there is clear evidence of repeated mismatch between what the person says and what they do.

    This means that in practice it is unlikely to be possible to conclude that the person lacks capacity as a result of their impairment on the basis of one single assessment.

    Understanding information about the decision to be made

    It is important not to assess someone’s understanding before they have been given relevant information about a decision. Every effort must be made to provide information in a way that is most appropriate to help the person to understand. Quick or partial explanations are not acceptable unless the situation is urgent.

    Relevant information includes:

    Examples of effective communication to support the person understand the relevant information include:

    1. A person with a learning disability may need somebody to read information to them. They might also need illustrations to help them to understand what is happening or they might stop the reader to ask what things mean. It might also be helpful for them to discuss information with an advocate.
    2. A person with anxiety or depression may find it difficult to reach a decision about treatment in a group meeting with professionals. They may prefer to read the relevant documents in private. This way they can come to a conclusion alone and ask for help if necessary.
    3. Someone who has a brain injury might need to be given information several times. It will be necessary to check that the person understands the information. If they have difficulty understanding, it might be useful to present information in a different way (for example, different forms of words, pictures or diagrams). Written information, audiotapes, videos and posters can help people remember important facts.

    It is only after all practicable steps to support the person to understand have been unsuccessful can you look at taking the decision for the person in their best interest. You cannot make a best interest decision for someone who has the capacity to make the decision themselves.

    Is the decision in the persons best interest?

    Although there is no single definition of what would be in a person’s best interests, the Code of Practice gives a non-exhaustive checklist of things that must be considered when another person is making a decision. You need to weigh up these factors in order to work out what is in the persons best interest.

    Assess whether the person might regain capacity

    For example, after receiving medical treatment. If they might, could the decision be postponed? If so, do so.

    Encourage participation

    Do whatever's possible to encourage and support the person to take part and as far as they're able. At its heart the MCA is an empowering piece of legislation.

    Find out the person's views

    Including their past and present wishes and feelings - these may have been expressed in writing or through behaviours or habits.

    Any beliefs or values – e.g. religious, cultural, moral and political that may influence the decision.

    Identify all relevant circumstances

    Try to identify the things the individual lacking capacity would take into account if they were making the decision themselves.

    It is not substitute decision making which is where you put yourself in the situation and ask yourself, “if this was me what would I choose?”

    Avoid discrimination

    Don't make assumptions on the basis of age, appearance, condition or behaviour.

    Consult others

    If it is practical to do so, consult other people for their views about the person's best interest. In particular consult with:

    What else do you need to consider?

    Before any treatment or intervention on offer can be given to a person, legal authorisation must be obtained, ask yourself, “Under what legal framework?” For most this will be the authority of their informed consent. Remember, even where a Lasting Power of Attorney (LPA) for health and welfare is in place, do not assume that the person cannot consent to the particular decision at the time it needs to be made. Supported decision making remains, especially for clinical decisions.

    Avoid restricting the persons rights

    See if there are other options that may be less restrictive.

    If restraint is being considered, there needs to be a reasonable belief that it is necessary in order to prevent harm to the person. It needs to be a proportionate response to the likelihood of the person suffering harm, and the seriousness of that harm.

    Always consider if this could be a deprivation of the persons liberty and ask yourself:

    Deprivation of Liberty: all person’s aged 16 and over

    Does the restriction constitute a deprivation of the person’s liberty?

    If so, formal legal authorisation will be required, without which this deprivation of liberty will breach the person’s right to liberty under Article 5 of the European Convention of Human Rights - Right to liberty and Security (PDF, 895kb, 64 pages).

    Currently, unless authorised under an alternative legal framework such as the Mental Health Act 1983, the deprivation of liberty will need to be authorised under the:

    Identifying if a person is being deprived of their liberty

    • are they confined?

    • do they lack the mental capacity to give informed consent to the arrangements for them to receive care and/or treatment?

    • are these said arrangements imputable to the state? (Does a public body such as the Local Authority (LA) or NHS know about it?)

    Where all three elements are fulfilled, the person is being deprived of their liberty.

    In order to answer the first point, ‘are they confined’ one must deploy the ‘Acid Test’ from Cheshire West as follows:

    All three elements must be present. If they are, a DoLS application must be made to:

    The Mental Capacity (Amendment) Act 2019

    The Mental Capacity (Amendment) Act (referred to as ‘the Act’ hereafter) both repeals and replaces DoLS with a new scheme called the Liberty Protection Safeguards (LPS) applicable in all settings for people aged 16 years and over.

    At the time of writing there is no implementation date for the Act which will bring LPS into force.


    Therefore, any young person subject to S.20, S.31 or S.39 of the Children Act 1989 will fall within the scope of the Act, as well as other arrangements such as family fostering.

    For further information, please see the following 11-minute animation - LPS: A visual summary of what you need to know.

    The MCA Code of Practice

    Professionals and carers must have regard to the Code and record reasons for assessing capacity or best interests. If anyone decides to depart from the Code, they must record their reasons for doing so. The code is at the time of writing (November 2020) which will introduce the Liberty Protection Safeguards (LPS) scheme to replace the Deprivation of Liberty Safeguards (DoLS) scheme.

    Currently, the original Code of Practice remains in force.

    The MCA Code of Practice
    PDF, 975KB, 301 pages

    However, the Mental Capacity (Amendment) Act 2019 (which brings Liberty Protection Safeguards (LPS) into statute) Code of Practice has been released in draft form as follows:

    Mental Capacity Act 2005 Code of Practice, including the Liberty Protection Safeguards (
    PDF, 3200KB, 518 pages

    Record Keeping

    The Code of Practice advised that assessments of capacity by professionals should be recorded. You should keep a record of the process for working out best interest relevant for each decision. If you are not following the written wishes of the person now lacking capacity the reasons must be recorded.


    Read more about Deputies

    Advance Decisions

    Learn more about Advance Decisions

    Independent Mental Capacity Advocates (IMCA)

    Independent Mental Capacity Advocates (IMCA)

    Other resources

    Mental Capacity Act 2005 Code of Practice, including the Liberty Protection Safeguards

    The Toolkit - Mental Capacity Toolkit

    Video: Using the Mental Capacity Act in the community

    BMA Mental Capacity Act Toolkit

    GMC Decision Making Tool

    Royal College of Psychiatrists

    Care Quality Commission

    Council for Disabled Children Decision Making Toolkit

    Council for Disabled Children Capacity and EHC plans

    SCIE MCA resources

    39 Essex Street MCA Newsletters
    LPS: A visual summary of what you need to know (11 minutes)

    Video: Liberty Protection Safeguards - Looking forwards - for social care | SCIE

    Rapid Response Webinars - Essex Autonomy Project

    Capacity guide - The situation seems risky to me

    Pan-London NHS: MCA lead toolkit

    Liberty Protection Safeguards - elearning for healthcare (

    NHS Learning Hub

    Resources specifically regarding under 18-year-olds.

    Video about 16/17-year-olds and the MCA

    39 Essex Chambers are working on a guidance note about 16/17 year olds and the MCA: current guidance notes on capacity and best interests are here, along with a guidance note on deprivation of liberty and those under 18:

    This guidance may help in terms of thinking about capacity assessment, especially in terms of more complex cases:

    Serious medical treatment guidance

    The Council on Disabled Children's website resource about the framework for decision making
    PDF, 393kb, 36 pages

    Children - Which Decision Counts? – Part One: Medical Treatment Decision

    Consent to treatment - Children and young people - NHS (