In all areas of health care or social care, it is likely that you will encounter people with an intellectual disability, and it is essential to understand the principles of consent as applied to this population.

Keri-Michèle Lodge, Consultant in Psychiatry of Intellectual Disability, Leeds and York Partnership NHS Foundation Trust

This article updates the original by Jane Bernal, published prior to the 2005 Mental Capacity Act, now located in the Historic Articles section of this website.

This is a basic guide informed by the Mental Capacity Act, 2005, which applies to England and Wales. As the law relating to decision-making and consent, particularly for patients who lack capacity, varies across different countries, healthcare professionals need to understand the law as it applies where they work.


  • 1.  You are a doctor working in general practice/family medicine and have been asked to examine the abdomen of Jenny, a 41-year-old woman with a moderate intellectual disability who has been having heavy periods and abdominal pain.  You tell Jenny that you would like to check her tummy.  She shakes her head and refuses to lie on the examination couch.  What do you do?
  • 2.  You are a nurse working in the Emergency Department and have been asked to perform a blood test for Andrew, a 19-year-old man with a mild learning disability, who is pale and breathless.  When Andrew sees your blood-taking equipment, he shouts “No needles, no, no”.  His mother says she wants you to “just get on with it.”  What should you do?
  • 3.  You are a doctor working in the Neurology outpatient clinic at a district general hospital and are reviewing Isaiah, a 20-year-old man with a mild learning disability.  He has cerebral palsy, and cannot speak although can communicate using head movements, smiling and pointing with his eyes to objects in the world and on a Bliss communication board.  He has developed absence seizures, a form of epilepsy.  You offer to prescribe anti-epilepsy medication, but Isaiah says he hates taking tablets and does not think treatment would be worthwhile because his absences are not causing him any problems.  What do you do?
  • 4.  You are a social worker and have been asked to see Aisha, a 49-year-old woman with a mild learning disability, who is currently in emergency respite because her mother and main carer is in hospital recovering from breaking her hip after a fall at home.  Aisha knows her mother is in hospital and she wants to go home to get everything clean and tidy ready for her mother coming home.  Her emergency respite carers are worried that she would not be able to manage at home on her own, and have been trying to persuade Aisha to stay for another few days.  However, Aisha is clear that she wants to go home today, has packed her bags and is asking to leave.  What do you do?


The above scenarios are examples of situations a health or social care professional may find themselves in.  No matter which area of health care or social care you work in, it is likely that you will encounter people with an intellectual disability, and it is vital to understand the principles of consent as applied to this population.


In terms of healthcare, all adults should be asked for their permission before receiving healthcare interventions including examinations, procedures, interventions, investigations, treatments and referrals – in other words, they should consent to this.  This is also true for people with an intellectual disability, but is complicated by literacy problems, communication problems and assumptions by professionals about whether the person is able to make a decision or not.  Guidance from the General Medical Council (GMC) makes it clear that “All patients have the right to be involved in decisions about their treatment and care and to make informed decisions if they can” (  The GMC’s guidance makes it clear that a person-centred approach should be taken to assessing capacity, requiring doctors to: be polite and considerate; let patients know if they can exercise choice about any aspect of their treatment and respect their choices; and keep patients informed about their progress and regularly review decisions made

A proper understanding of consent is as central to the ethics of what healthcare professionals do as it is to its legality.  All health professionals are guided by key ethical principles, including respecting the personal autonomy of the people who use their services.  They must try to do good (beneficence) and avoid doing harm (non-maleficence).  The principle of consent is also fundamental to international human rights law.

For consent to be valid, it must be:

  • Voluntary - the decision to either consent or not to consent must be made by the person, and must not be influenced by pressure from medical staff, friends or family.
  • Informed – the person must be given the relevant information about benefits, risks, reasonable alternatives and the consequences
  • Made with capacity – in other words, the person must have the mental capacity to use the information given and to use this to make and communicate a decision

It is not always necessary for obtaining a patient’s consent to be a formal process.  For many healthcare decisions, patients may give consent verbally, for example by saying “Yes” when you ask to examine them, or non-verbally, for example, holding out their arm for a blood test.  However, even in these situations, it is important to ensure you have explained what you want to do and why, and to make it clear that the patient can say no.

To provide a framework for assessing mental capacity to consent, with the aim of empowering people to make their own decisions wherever possible, the Mental Capacity Act (MCA) was introduced in 2005 and applies to people aged 16 or over in England and Wales ( ).  Although both health and social care professionals have a responsibility to practice in accordance with the MCA, knowledge and application of the MCA Act is poor.  Understanding the key principles of the MCA is vital for healthcare professionals seeking consent.  If we don’t understand how to assess mental capacity, then our judgements on a person’s ability to consent to or refuse examination, investigation or treatment may be flawed, with potentially life changing consequences for that individual.  It is important to note that the clinician providing the proposed intervention or treatment (referred to as ‘the treating clinician’) has responsibility for assessing the patient’s mental capacity to consent.

Mental Capacity Act 2005

Within the MCA, ‘mental capacity’ refers to a person’s ability to make a particular decision at a particular time.  We all make many decisions every day – think about how many decisions you have made so far today: perhaps, what to eat for breakfast, what to wear, when to cross the road?  Within healthcare, some decisions are more complex, for example, whether we want to take the medication suggested.  Within social care, complex decisions might include deciding where to live, making a decision about what kind of social care to have, and deciding who to live with.

The MCA makes it clear that capacity is decision-specific, meaning that a person may have the mental capacity to make some decisions, such as which socks to wear, but may lack the mental capacity to make other decisions, such as whether to consent to having a blood test or not, or whether to have sex or not.  It is wrong to refer to a person as having or lacking capacity for all decisions.

Jenny (Box 1)  may be able to choose whether to take ibuprofen when she has period pains, but may or may not have capacity to consent to laparoscopy.  She may have the mental capacity to consent to laparoscopy but not to hysterectomy.  Why might this be? In the first place, it is much easier to understand an immediate treatment to relieve a current symptom, pain, than it is to understand the need for investigation. Understanding distant long-term consequences, like sterility or disease prevention, is cognitively more difficult than dealing with an immediate problem. Understanding hysterectomy also involves some basic anatomy and physiology.  Jenny may be able to understand the idea of the doctor looking in her tummy without having much idea of where her womb is or what it does.

Key principles of the Mental Capacity Act

There are five key principles underlying the MCA (see Box 2).  First, it should be assumed that the individual has capacity to make their own decisions, regardless of their level of ability or disability, unless proven otherwise.  In other words, healthcare professionals should not assume that a patient with an intellectual disability will be unable to make their own decisions.


    1.  Assume the individual has capacity.

    2.  A person must be assumed to have capacity unless it is established that they lack capacity.  A person cannot be deemed to lack capacity unless all practicable steps to help him to do so have been taken without success.

    3.  Respect the individual has a right to make an unwise or eccentric decision.

    4.  When the individual lacks mental capacity, others may make a decision, and the decision taken must be in the individual’s best interests.

    5.  When decisions are taken on behalf of an individual, the decision taken should be the least restrictive – in other words, it should be the decision which least interferes with the rights and freedoms of the individual.

Assessing capacity requires an exchange of information – the healthcare professional needs to explain to the patient what they want to do, the potential benefits and the potential risks.  In turn, the patient needs to think about this information and communicate their decision.  The second key principle (Box 2) makes it clear that healthcare professionals must support a patient to make a decision, and key to this is communicating in a way the patient can understand.  Under the Equality Act 2010, there is a legal duty for public bodies, such as the National Health Service, to make reasonable adjustments to meet the needs of people with an intellectual disability.  When it comes to assessing capacity, health care professionals may need to provide reasonable adjustments to their communication, for example:

  • Ensuring you understand how best to communicate with the person and how they communicate with others – for a person with a learning disability, this may include the use of Makaton, computers or other electronic communication aids, and may require consultation with a speech a language therapist
  • Having a relative, friend, carer, advocate or other supporter present to assist with communication and to put the person at ease
  • Discussing the information at the time of day when the patient’s understanding is better
  • Discussing the information in a place in which the patient is most likely to feel at ease
  • Using clear words and short sentences
  • Providing information in an accessible format, such as pictures or videos rather than words
  • Providing extra time for the person to process information

In Andrew’s case (Box 1), it may be that he feels very worried about being in the Emergency Department and being unwell.  The healthcare professional should take the steps above to optimise his ability to make a decision about having a blood test.  This might include moving Andrew to a quiet area within the Emergency Department, asking his support worker to be present to help Andrew feel calm, and using pictures to explain the procedure, such as “Jack has a blood test” (Books Beyond Words).

The MCA Code of Practice ( makes it clear that those assessing capacity should take all practicable steps to support a person to make a decision, and in addition to the above, for a person with an intellectual disability, this may include providing structured support to help them learn new information or skills relevant to making the decision.

The third key principle (Box 2) makes it clear that a person should not be deemed to lack capacity because they make a decision which others (which may include health and social care professionals) disagree.  For example, Isaiah (Box 1) is clear that he doesn’t want to take epilepsy medication.  In this situation, it should not be assumed that he lacks capacity.  Instead it is important to explore his understands and beliefs around medication, along with his understanding of the consequences of his decision.  It is also important to be aware of any undue pressure he may be under from other people about this decision.  People with an intellectual disability may be particularly vulnerable to pressure from others.  If a health or social care professional is concerned that a person is under undue pressure from others, they should follow adult safeguarding procedures, which vary from country to country.

How is mental capacity assessed?

The MCA outlines a two-stage test to assessing capacity:

  1. Does the person have an impairment of the functioning of their mind or brain?
  2. Does the impairment mean that the person is unable to make the decision?

A person with a more severe intellectual disability may have impairment of the functioning of their mind or brain as a consequence of their intellectual disability.  However, this may or may not mean that they are unable to make the relevant decision.  To determine whether the person is able to make the decision, the following four factors are assessed:

a. The ability to understand information about the decision to be made;

b. The ability to retain the information long enough to make the decision;

c. The ability to use or “weigh up” the information as part of making a decision; and

d. The ability to communicate their decision through any means.

If a person is unable to do one or more of the above, then they may be deemed unable to make the decision.

If both stages of the two-stage mental capacity test are satisfied, then a person may be deemed to lack capacity. However, it is important to be aware that capacity can fluctuate, and if a decision can be delayed, consideration should be given to assessing capacity again at a more optimal time.

The MCA makes it clear that an assessment that a person lacks capacity to make a decision should never be based simply on:

  • their age
  • their appearance
  • assumptions about their condition, or
  • any aspect of their behaviour.

For example, in Isaiah’s case (Box 1), assumptions should not be made about his ability to make a decision about his treatment simply based on the effects of his cerebral palsy, including his inability to speak.

When a healthcare decision cannot wait, for example, in an emergency, the principles of the MCA remain the same – it should be presumed that a conscious patient has capacity to make decisions and consent should be sought.  However, when a patient in these circumstances is deemed to lack capacity, healthcare professionals can provide treatment that is immediately necessary to save their life or prevent a serious deterioration of their condition.  Their capacity should be reassessed and they may be able to regain capacity once sufficiently recovered from their emergency.

Best interests decisions

If a patient is deemed to lack capacity to make the relevant decision, for example, to have a blood test, a decision must be made for them and must be in their best interests.  This usually requires the relevant health and/or social care professionals to arrange a best interests decisions meeting at which all those with an interest in the decision being made, which may include the person’s parents or other family members, try to agree a decision in the person’s best interests.  If they don’t know about the MCA, parents, such as Andrew’s mother (Box 1) can be surprised by the change in how decisions are made about their son or daughter once they reach the age of 16.  If they have been making decisions for their child throughout their life, they may have expected that they would continue to do so.  However, the views of parents/families and carers must be taken into consideration when decisions are being made in the best interests of someone who lacks capacity.  It is important to provide parents with information on decision-making for their adult child so that they can understand what is happening.

There is no clear definition of “best interests.”  However, the MCA makes it clear that, when others are making a decision on behalf of a person, they should seek to make a decision that would result in the least interference with their basic human rights and freedoms.

In some circumstances, parents/families may wish to seek formal legal powers to make particular decisions on behalf of their relative.  For matters relating to personal welfare, such as care and treatment, these include an attorney appointed under a Lasting Power of Attorney or a Deputyship appointed by the Court of Protection.

Other people who should be consulted when making a decision in the best interests of a patient who lacks capacity include:

-anyone previously named by the person as someone to be consulted on the decision in question

-anyone engaged in caring for the person

-close relatives, friends, or other who take an interest in the person’s welfare

Some people with a learning disability may not have anyone who fits the above categories, in which case, where major medical treatment decisions are being made, an Independent Mental Capacity Advocate (IMCA) should be consulted.

The aim of consulting with these other people is to try to identify the patient’s past and present wishes and feelings, their beliefs and values, and the things they would take into account if they were making the decision themselves.  Sometimes, patients may have made an advance decision to refuse a particular treatment at a time when they had capacity to make this decision – in this situation, healthcare professionals must respect this decision if they deem it to be valid and applicable to the proposed treatment.

Following consultation, all the above factors must be weighed to come to a decision about what course of action would be in the best interests and would least restrict the freedom of the person who lacks capacity.

There may be times when there is disagreement between those involved in the process as to what decision is in the patient’s best interest.  When this occurs, an IMCA’s views may be useful, and there may be the option for a second opinion.  However, if the dispute cannot be resolved, ultimately the Court of Protection may need to decide what is in the person’s best interests.

Sometimes, best interests decisions may result in restricting the freedoms of the person who lacks capacity.  For example, Andrew (Box 1) was found to lack capacity to make a decision about having a blood test, it may be decided that it is in his best interests for him to have this procedure to investigate possible causes of his paleness and breathlessness.  However, despite being provided with accessible information on having a blood test, Andrew may remain anxious and may continue to decline to hold out his arm.  A further decision would be needed about whether restraining Andrew to facilitate the procedure would be in his best interests or not.

In situations like this, healthcare professionals must ensure any restraint used is necessary to prevent harm to the patient, and a proportionate response to the likelihood and seriousness of harm (Box 3).  In addition, the GMC’s guidance on decision-making and consent makes it clear that if it is decided that it is in the patient’s best interests for their freedoms need to be restricted, for example, being restrained for a procedure, this must be for the minimum time and in the least restrictive way possible, and with respect for their privacy and dignity.


  • You discuss with Andrew’s mother that you are concerned his symptoms may indicate anaemia.  You discussed that, if this is not identified, it could worsen and Andrew might become more unwell.  You agree that it would be in Andrew’s best interests for his mother to hold his hand to allow you to take the blood samples you need.  Andrew allows his mother to hold his hand with his arm outstretched.  She shows him his favourite music videos on her mobile phone whilst you complete the blood-taking procedure.  Andrew flinches a little, but is able to keep still enough with his mother holding his hand firmly.  Once you have finished, his mother lets go of Andrew’s hand and passes him a drink.

It is important that healthcare professionals involved in significant restraint are trained in providing this safely and effectively, and that they follow guidance on restraint and physical intervention.  Restraint can be a traumatic experience for a patient, and it is important for healthcare professionals to consider how restraint may impact on the person’s wellbeing.

Deprivation of liberty

In some cases, the degree or intensity of restriction of a person’s liberty in providing healthcare may amount to a “deprivation of liberty.”  For example, it was decided that it would be in the best interests of Jenny (Box 1) to be admitted to the Gynaecology ward at the local hospital for further investigations and treatment.  However, she repeatedly asked the nurses to let her go home, and on a daily basis, the hospital security team was called to sit with Jenny because of her attempts to leave the ward.   In this situation, although it is thought necessary for Jenny to be in hospital for her treatment, this may amount to a deprivation of her liberty.  The hospital would need to apply to the Local Authority for legal authorisation to deprive Jenny of her liberty under the Deprivation of Liberty Safeguards (DoLS) process (shortly to be replaced by the Liberty Protection Safeguards).  Similarly, Aisha’s is being deprived of her liberty in emergency respite (Box 1), and the social worker needs to assess whether she has the mental capacity to consent to her care arrangements, and if she is deemed to lack capacity to make a decision about this, an urgent DOLS application is required.

It is important that when a person is going through the DOLS process, the health and social care professionals involved ensure they are provided with accessible information and support to understand what is happening and why.  They also need information on how they can challenge their deprivation of liberty.  An IMCA can help explain the DOLS process to the person.  Their carers or family also need to be provided with this information.

It should be noted that when a person is admitted and treated in a mental health hospital, which, for people with an intellectual disability, may be known as an Assessment and Treatment unit, there is added complexity because of the overlap between the MCA and the Mental Health Act 1983 which governs compulsory admission and treatment in hospital for people with a mental disorder in England and Wales.  It is outside the scope of this article to discuss this, but a useful summary is provided by Sorinmade, Ruck Keene and Moylan The law relating to compulsory admission to and treatment in psychiatric hospitals varies across countries, and professionals must understand the law as it applies where they work.


People with an intellectual disability have the same rights as anyone else to be asked for their consent for healthcare interventions, and have the same right as anyone else to be involved in making decisions about their health and social care.  This basic introduction to consent has highlighted that health and social care professionals must not assume that a person with an intellectual disability will be unable to make the relevant decision, and have a duty to adjust their communication to support the person to be involved in making the decision.  When a mental capacity assessment concludes that a person with an intellectual disability is unable to make a specific decision about their health or social care, a best interests decision must be taken about how to proceed in a way which least restricts the person’s freedoms.  Family members, friends, carers, advocates and other supporters can play a vital role in understanding how best to communicate with a person with an intellectual disability, and in understanding what the person’s wishes, beliefs and values are when making best interests decisions.

Other resources

Easy Read information on the Mental Capacity Act 2005 is provided by Care England

For people with a learning disability, their families and carers, the Mental Capacity Act resource sheet produced by Mencap may be helpful and can be found here

Further guidance on assessing mental capacity in the context of healthcare is provided within the British Medical Association’s Mental Capacity Act toolkit

Further information on DOLS is provided by the Social Care Institute for Excellence

Further information on the Liberty Protection Safeguards, which will replace DOLS and are due to come into force in April 2022, is provided by the Department of Health and Social Care

There are other legal situations in which a person's mental capacity may be questioned, for example you might want to know if a person is able to make a will, to participate in research, to consent to have sex, to get married, to make a decision about where to live, or to take out a mortgage.  The MCA applies to these scenarios, and health and social care professionals may be involved in mental capacity assessments in such cases.  You should familiarise yourself with the guidance of your professional body.  You may also wish to keep up to date with relevant cases before the Court of Protection

If you have not already read them, these articles on clinical communication and Books Beyond Words will also help you obtain truly informed consent.

My Adult – Still My Child” is a guide for parent/carers of adults (16+) who may not be able to  make decisions .

First published on this site in December 2021.