Mental Capacity Act

Last updated on 12 Oct 2021

The Mental Capacity Act 2005 (MCA) provides a comprehensive framework for decision making on behalf of adults aged 16 and over who are unable to make decisions for themselves, i.e. they lack capacity.

The Act applies in England and Wales only. The Act applies to all decisions taken on behalf of people who permanently or temporarily lack capacity to make such decisions themselves, including decisions to include such people in research. 

All researchers working with research participants who lack, or may lack, capacity need to be aware of its underlying principles and the provisions relating to research. 

The Act is accompanied by a statutory Code of Practice providing guidance on how it should be used. Researchers and others making decisions involving people lacking capacity have a legal duty to have regard to the guidance in the Code of Practice. 

In addition to the information below, the HRA provides a free eLearning module on research involving participants lacking mental capacity.

What are the core principles of the Act? 

Section 1 of the Act sets out a number of core principles. These are rooted in the common law, ethical guidelines and best practice and are designed to be fully compliant with the relevant sections of the Human Rights Act. 

These principles are: 

  • a person must be assumed to have capacity unless established otherwise 
  • individuals should be helped to make their own decisions as far as practicable 
  • a person is not to be treated as unable to make a decision merely because he makes an unwise decision 
  • all decisions and actions must be in the best interests of the person lacking capacity 
  • all decisions and actions must be the least restrictive of the person’s rights and freedom of action. 

What is capacity? 

Capacity refers to the everyday ability that individuals possess to make decisions or to take actions that affect them, from simple decisions such as what to have for breakfast to far-reaching decisions about serious medical treatment or financial affairs. 

A person lacks capacity if he or she is unable to make or communicate a decision about a particular matter because of an impairment of, or a disturbance in, the mind or the brain. 

This may be the result of a variety of conditions, including: 

  • dementia 
  • mental illness 
  • learning disability 
  • brain damage 
  • intoxication 
  • any other condition causing confusion, drowsiness or loss of consciousness (e.g. concussion, stroke, heart attack, epileptic fit, serious accident, delirium). 

How is capacity assessed? 

The Act contains a two-stage test of capacity: 

  • Is there an impairment of, or disturbance to, the functioning of the mind or brain?

And if so; 

  • Is the impairment or disturbance sufficient that the person is unable to make that particular decision? 

The Act says that a person is unable to make a decision if unable to: 

  • understand the information relevant to the decision 
  • retain the information 
  • use or weigh the information 
  • communicate his or her decision (by any means). 

A person with a duty of care must assess capacity to make a particular decision at the time the decision needs to be made, and should not assume that a person cannot make any decision. A person’s loss of capacity may be temporary, and capacity may fluctuate. 

Some people may lack capacity to make a complex decision but retain the capacity to make other decisions. The duty to assess capacity also applies to researchers when recruiting participants into, and conducting, intrusive research. For further guidance on assessing capacity, see Chapter 4 of the statutory Code of Practice. 

Whose responsibility is it to decide whether a potential participant has the capacity to consent for themselves to research?

This is the responsibility of the researcher, consulting as appropriate with other care professionals. 

Scope of the research provisions 

Does the Mental Capacity Act apply to my research?

The Act applies to any intrusive research within England and Wales, wherever it takes place, except for clinical trials of investigational medicinal products. This may include research in healthcare, social care, criminal justice and other settings. It is not limited to research undertaken within NHS organisations or other public bodies. 

Which parts of the Act apply to research? 

Sections 30-33 of the Act provide lawful authority for intrusive research to be carried out involving people without capacity provided that the research has been approved by an appropriate body. Section 34 makes transitional provisions relating to the loss of capacity in research which started before 1 October 2007. 

What is 'intrusive research'?

Under Section 30 of the Act, research is intrusive if it is of a kind that would be unlawful if it was carried out 'on or in relation to a person who had capacity to consent to it, but without this consent'. Therefore intrusive research means research that would legally require consent if it involved people with capacity. Intrusive research is not limited to trials of clinical interventions. 

It includes non- interventional research where consent is legally required, for example involving the processing of personal data or the administration of questionnaires, interviews or observations. Intrusive research involving a person who lacks capacity is unlawful unless it is approved by an appropriate body. 

What research is not intrusive? 

Consent is not a legal requirement, and therefore the research is not intrusive, if it is limited to one or more of the following: 

  • processing of non-identifiable data
  • processing of identifiable patient data with the approval under Section 251 of the NHS Act 2006 (or formerly under Section 60 of the Health and Social Care Act 2001)
  • use of tissue samples (cellular material) held prior to the coming into force of the Human Tissue Act on 1 September 2006 ('existing holdings')
  • use of tissue samples (cellular material) taken from a living person, provided that the person is not identifiable to the researcher and the research project has ethical approval
  • use of the results of the analysis of DNA in material taken from a living person, provided that the person is not identifiable to the researcher and the research project has ethical approval. 

Does the Mental Capacity Act apply to clinical trials of investigational medicinal products (CTIMPs)? 

No. Under Section 30 of the MCA, CTIMPS are specifically excluded from the research provisions of the Act. This is because separate provision is made for including adults lacking capacity in CTIMPs in Schedule 1 of the Medicines for Human Use (ClinicalTrials) Regulations 2004. 

Further information about these provisions is available in our information paper on informed consent in CTIMPs.

Do the research provisions apply in Northern Ireland? 

No. The Mental Capacity Act only applies to England and Wales. In Northern Ireland, the inclusion of adults lacking capacity in research is governed by the Section 132 provisions of the Mental Capacity Act (Northern Ireland) 2016. However, as the acts that apply in Northern Ireland, England and Wales are closely aligned, a scheme of mutual recognition of NHS/HSC research ethics committee (REC) review for research involving adults lacking capacity to consent has been agreed between these three nations.

Do the research provisions apply in Scotland?

No. The Mental Capacity Act only applies to England and Wales. In Scotland, the inclusion of adults lacking capacity in research is governed by the provisions of Section 51 of the Adults with Incapacity (Scotland) Act 2000.

Do the research provisions apply to children? 

In general the Act applies only to people aged 16 and over. There are a few exceptions, which are explained in Chapter 12 of the Code of Practice. For projects involving children under the age of 16, researchers and research ethics committees are advised to follow existing guidance, such as that provided by the Medical Research Council

Do projects not classified as research require approval under the Mental Capacity Act? 

No. The provisions of Sections 30-34 of the Act apply only to intrusive research. 

Appropriate body 

What is the role of the appropriate body? 

The appropriate body is responsible for approving intrusive research involving adults lacking capacity. It must be satisfied that all the criteria in Section 31 of the Act are met, including that arrangements are in place to satisfy the requirements of Sections 32 and 33. 

Who can act as the appropriate body? 

All NHS RECs established under Governance Arrangements for Research Ethics Committees (GAfREC) in England and Wales, and the Social Care REC, are appropriate bodies for the purposes of approving research under the Mental Capacity 2005 (England and Wales) Act. The Ministry of Defence RECs are also recognised for research within their remits.

Although legally any REC established under GAfREC in England / Wales may approve research under the Act, a panel of flagged RECs for research involving adults unable to consent for themselves has been established.

University ethics committees are not recognised as Appropriate Bodies under the Act.

Enquiries about recognition of committees under the Act should be directed to the HRA.

Applications under the Mental Capacity Act relating to research outside the NHS will be accepted for review by NHS RECs.

Joint statement regarding mutual recognition of Research Ethics Committee (REC) review for research studies involving adults lacking capacity to consent for themselves in Northern Ireland and England and/or Wales.

The following statement applies to ethical review of research studies that:

  • Involve adults lacking capacity to consent for themselves; and
  • Are not clinical trials of investigational medicinal products (non-CTIMPs); and
  • Are taking place in Northern Ireland and England and/or Wales

In October 2019, the Mental Capacity Act (Northern Ireland) 2016 came into operation. This act is closely aligned with Mental Capacity Act 2005, which applies in England and Wales. This means that a scheme of mutual recognition of NHS/HSC research ethics committee (REC) review for research involving adults lacking capacity to consent has been agreed between these three nations.

In practice this means that for a research project involving adults lacking capacity to consent and with sites in England/Wales and Northern Ireland only requires one NHS/HSC REC review as long as the NHS/HSC REC undertaking the review is recognised as an Appropriate Body by either:

Applying for approval under the Act 

Which REC should I apply to? 

The Research Ethics Service has flagged a number of NHS RECs in England and Wales to review new applications for approval under the Mental Capacity Act. Members of these RECs have had additional training in issues relating to the MCA. 

Applications should be booked with our Online Booking Service so they can be allocated to an appropriate REC. 

Are there any specific requirements for applications under the Act? 

The application form, available via the Integrated Research Application System (IRAS), incorporates specific questions about compliance with the Act in Part B Section 6 of the form. 

The study protocol should describe the procedures for recruiting people lacking capacity, including arrangements for identifying and consulting consultees. 

If appropriate, procedures should be described for seeking consent from participants who may regain capacity during the study. 

What happens where research is conducted in Scotland as well as England or Wales? 

Research conducted in England/Wales and Scotland requires separate approvals under the Mental Capacity Act and the Adults with Incapacity (Scotland) Act 2000 respectively. 

Separate applications should be made to recognised RECs in each jurisdiction. In Scotland, the application must be made to the Scotland A REC and should include a consent form for the guardian, welfare attorney or adult’s nearest relative. Guidance on documentation to be used in recruiting participants lacking capacity in Scotland is available in our guidance on information sheets and consent forms. 

What happens where research is conducted in Northern Ireland as well England and/or Wales?  

If the research is taking place in England or Wales as well as Northern Ireland, only one application is needed. The application should be made to a flagged REC in England or Wales or Northern Ireland

Further guidance is available in our standard operating procedures and in our guidance on information sheets and consent forms.

What is the position for research that started before the Act came into force? 

Any intrusive research involving adults lacking capacity, that started prior to 1 October 2007, required further approval from a recognised REC under Section 30 of the Act by 1 October 2008. 

If such approval has not been obtained, it is no longer lawful to undertake any intrusive research procedures on or in relation to adults lacking capacity. 

Approval criteria 

What are the requirements for approval? 

The approval criteria are set out in Section 31 of the Act:

  1. The research must be connected with an impairing condition affecting the participant or its treatment. 
  2. Research of equal effectiveness could not be carried out if confined to participants with capacity. 
  3. The research must either: (a) have the potential to benefit the participant without imposing a disproportionate burden, or (b) provide knowledge of the causes of, or treatment or care of others with, the same or a similar condition – in this case the research must involve negligible risk to the participant, not interfere significantly with their freedom of action or privacy, or be unduly invasive or restrictive. 
  4. Arrangements must be in place to comply with section 32 (consulting carers) and section 33 (additional safeguards). 

What arrangements need to be in place to comply with Section 32?

The researcher must have adequate arrangements in place for consulting consultees about whether a person lacking capacity should take part in the research. 

Reasonable steps must be taken to identify a 'personal consultee'. If no appropriate person can be identified who is willing to act as a personal consultee, the researcher may consult a 'nominated consultee', i.e. a person independent of the project appointed in accordance with the Department of Health’s guidance on nominating a consultee for research involving adults who lack capacity to consent

The consultee must be given information about the project and advise on what the participant’s wishes and feelings would be about taking part. 

The consultee gives advice rather than consent. The advice of the consultee must be respected. If the consultee so advises, the participant must not take part and, if already taking part, must be withdrawn unless withdrawal of treatment would involve significant risk to the participant’s health. 

Where urgent treatment is to be provided, the Act allows exceptionally for a person lacking capacity to be entered into research prior to a consultee being consulted, subject to strict conditions. 

What arrangements need to be in place to comply with Section 33? 

Nothing must be done to which the participant appears to object unless it is to protect him/her from harm, or reduce or prevent pain or discomfort. If the participant indicates he/she wishes to be withdrawn, this must be done without delay unless there would be a significant risk to his/her health. 

Any advance statement by the participant must be respected. In conducting the research, the interests of the participant must always be assumed to outweigh those of science and society. 

Consultees 

Who can act as a consultee? 

A 'personal consultee' means a person who is: 

  • engaged in caring for the participant (not professionally or for payment) or is interested in his/her welfare, and 
  • is prepared to be consulted. 

If no appropriate person can be identified who is willing to act as a personal consultee, the researcher may consult a 'nominated consultee', i.e. a person independent of the project appointed in accordance with the Department of Health’s guidance on nominating a consultee for research involving adults who lack capacity to consent

What is the role of the consultee? How do I find more if I am approached to be a consultee? 

The consultee advises the researcher on what the participant’s wishes and feelings would be if they were able to consent for themselves, and on whether they should take part. The consultee does not give consent, only advice. 

The responsibility to decide whether the participant should be entered into the research lies ultimately with the researcher. Further information is available in the Department of Health’s guidance on nominating a consultee for research invovling adults who lack capacity to consent

Can a paid carer act as a personal consultee? 

No. However, where no personal consultee can be identified, a paid carer could act as a nominated consultee provided they had no connection to the research project. 

Is there a hierarchy of relatives the researcher should approach? 

The Act does not specify a hierarchy. It is a matter of judgment for the researcher, in consultation with the participant’s care team, to identify the most appropriate person. This will normally be the participant’s usual carer or another person closely concerned with their welfare. This may or may not be the nearest relative. 

What information should be provided to the consultee? 

The application should include an information sheet for personal/nominated consultees, including the same level of information that the participant would receive if they had capacity. 

They should also be asked to sign a 'record of consultation' form to confirm that they have received this information and had the opportunity to ask any questions and give advice. If some participants may have capacity to give fully informed consent, or may regain capacity during the research, the application should also include an information sheet and consent form for them. 

For those lacking capacity but with some measure of understanding, consideration should be given to providing a simplified information sheet. 

Further guidance and examples of these documents are available in our guidance on information sheets and consent forms. 

Should the consultee continue to be involved during the study? 

Yes. If the study involves a series of procedures, it is good practice for the researcher to keep the consultee fully informed, for example by attending any research procedures and providing support to the participant. 

If the consultee advises that the participant should be withdrawn, the researcher must withdraw them unless this would produce a significant risk to their health. 

What should I do if the personal consultee becomes unavailable during the study, or is no longer willing to undertake the role? 

The researcher should take steps to identify another personal consultee to take on the role. If no other appropriate person can be identified, a nominated consultee should be approached. 

What if the treatment to be given as part of the research is urgent and there is no time to approach a consultee? 

Section 32(8) of the Act allows exceptionally for a person lacking capacity to be entered into research prior to a consultee being consulted. 

There are strict conditions: 

  • urgent treatment is to be provided and it is not possible to separate this from inclusion in the research 
  • it is not practicable to identify and consult a consultee before providing the treatment.

This exception only applies during the emergency situation. As soon as time allows, the researcher must then consult a consultee or seek the participant’s consent (if capacity has been recovered) about their continued inclusion in the research and use of any samples or data already collected. 

Consent 

Who do I seek consent from if a participant lacks capacity? 

Under the Mental Capacity Act, no-one gives consent on behalf of a person lacking capacity. Instead, the researcher is required to seek advice from a consultee on what the wishes and feelings of the person might be and whether or not they should take part. 

The consultee gives advice, not consent in law. Responsibility to decide whether the person should be entered into the research lies with ultimately with the researcher. 

Can researchers seek advance consent anticipating the loss of capacity, without needing approval under the Act? 

No. Consent does not survive the loss of capacity under common law. A person with capacity may make an advance statement about their wishes to be included in research, or not to be included. Such statements should be taken into account by the researcher if relevant to a particular study. 

However, the statement does not amount to consent. If the person lacks capacity to give consent at the time they are to be recruited, the requirements of the Act must be followed. 

Loss of capacity during research

I plan to withdraw any participants who lose capacity during the study. Does the study require approval under the Mental Capacity Act? 

No. However, ethical approval may still be required under other regulations or the policy of the host institution(s) for the research. 

What do I need to do if I wish to include adults lacking capacity into an existing study which already has ethical approval?

Where intrusive research is already underway, and it is proposed to include adults unable to consent for themselves for the first time, a notice of substantial amendment should be submitted to the REC together with the following: 

  • part B Section 6 of the REC application form
  • revised protocol
  • information sheets and consultation/consent/assent forms (as appropriate, depending on whether the study is a CTIMP or non-CTIMP and which UK jurisdiction(s) are involved). 

Should researchers monitor the capacity of participants during a study? 

A core principle of the Act is that capacity should be assumed unless established otherwise. If a participant has consented to take part, it may generally be assumed that capacity remains in place but the researcher should be alert to any changes suggesting that capacity has been lost. 

Where the research involves administration of questionnaires by post, consent is usually considered to be implied by return of the questionnaire. There is no need for the researcher to monitor capacity proactively. 

What if a patient loses capacity after they have already consented to take part in a study? 

Under common law, consent is generally not valid following loss of capacity. If you wish to keep the participant in the study and undertake further intrusive research, it must have approval under Section 30 of the MCA, and you will need to seek advice from a consultee on whether the participant should remain in the study. 

If you withdraw the participant and either destroy or anonymise any samples or data already collected, Section 30 approval is not required and you will not need to seek advice from a consultee. 

Where the participant gave specific consent to use samples and data following loss of capacity, these may be retained in identifiable form if this is necessary for the research. 

What is the role of the consultee under the Loss of Capacity Regulations? 

The researcher must seek advice from a consultee about the participant’s presumed wishes and feelings. The participant’s samples and data must be withdrawn if the consultee so advises or if the participant indicates he/she wishes the research to be discontinued. 

Regaining capacity during research 

What happens if a participant regains capacity during a study approved under the Act? 

The participant should be fully informed about the study and their consent sought to continue in it. If they do not wish to remain in the study, they must be withdrawn. Unless they give consent to retain and analyse any data and samples collected so far, these must be destroyed. Procedures for dealing with this situation should be included in the protocol. Further advice may be sought from the ethics committee if required. 

Other questions 

Can samples and data collected from participants lacking capacity in an approved study be used in a new study? 

Where the samples or data have been anonymised or effectively pseudonymised so they are not identifiable to the researcher, they may be used in a further study without requiring Section 30 approval under the Act. 

Where identifiable data is to be used in a new study, further approval should be sought under Section 30 of the Act. 

Where the samples or data were originally collected from participants with capacity and broad consent was given for future research, this consent can still be considered valid.

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