Mental Capacity Explained for UK Student Nurses

On placement, you may hear someone ask:

“Does this patient have capacity?”

It sounds like a yes or no question. Legally, it is much more specific.

A person may be able to make one decision but not another. They may also be unable to decide at 8am when they are acutely confused, then be able to decide later when their pain, infection or delirium has improved.

That is the first thing to remember:

Capacity is about a particular decision at the time it needs to be made.

Capacity Is Not a Diagnosis

Dementia, delirium, a learning disability, mental illness, brain injury or intoxication may affect decision-making, but none of these automatically proves that a person lacks capacity.

The assessment must focus on the actual decision. Can the person decide whether to take a medicine? Can they consent to a procedure? Can they understand the risks of leaving hospital today?

Someone may make a choice that staff or relatives think is unwise and still have capacity to make it. Disagreeing with the clinical team is not, by itself, evidence of incapacity.

Support Comes Before the Conclusion

Before deciding that a person cannot make a decision, the team should take practical steps to help them.

This might mean using plain language, giving information in smaller pieces, allowing more time, using pictures or communication aids, arranging an interpreter, checking hearing aids or glasses, treating pain, and choosing a quieter or more suitable time for the conversation.

If the decision is not urgent and the person’s capacity is likely to improve, it may be possible to wait and return to it later.

This is not an optional extra. Supporting the person to decide is part of respecting their autonomy.

England and Wales

In England and Wales, the main law is the Mental Capacity Act 2005. It applies to people aged 16 and over.

The Act begins with five statutory principles:

1. A person must be assumed to have capacity unless it is established that they lack it.
2. All practicable steps must be taken to help the person decide before treating them as unable to do so.
3. A person must not be treated as lacking capacity simply because they make an unwise decision.
4. Any act or decision made for a person who lacks capacity must be in their best interests.
5. The option chosen should interfere as little as possible with the person’s rights and freedom.

How is capacity assessed?

The Mental Capacity Act uses a two-stage test.

First, is there an impairment of, or disturbance in, the functioning of the person’s mind or brain?

Second, does that impairment or disturbance mean the person is unable to make this particular decision when it needs to be made?

A person is unable to make the decision if they cannot do one or more of the following:

• understand the relevant information
• retain it long enough to make the decision
• use or weigh it as part of the decision
• communicate the decision by any means

The two parts belong together. Difficulty understanding something does not establish lack of capacity until appropriate support has been tried and the difficulty is linked to an impairment or disturbance of the mind or brain.

Scotland

Scotland uses a different law: the Adults with Incapacity (Scotland) Act 2000.

It would be inaccurate to copy the Mental Capacity Act test and call it the Scottish process. The Scottish framework has its own definition of incapacity and its own principles.

Any action taken under the Scottish Act must benefit the adult and should only be taken when that benefit cannot reasonably be achieved without the intervention. It must be the least restrictive reasonable option.

The adult’s past and present wishes should be considered, appropriate support should be offered so they can communicate their views, and relevant people should be consulted where reasonable and practicable. The adult should also be encouraged to use and develop the skills they still have.

For treatment decisions, Scottish clinicians may also need to consider Part 5 of the Act and whether a valid Section 47 certificate is required. Students should follow local NHS board procedures and ask the registered professional responsible for the person’s care when they are unsure.

Northern Ireland

Northern Ireland has the Mental Capacity Act (Northern Ireland) 2016, but it is being brought into force in phases.

Phase One introduced provisions mainly concerning deprivation of liberty, research, and money and valuables. The wider Act has not yet been fully commenced, so it is misleading to write as though the whole 2016 Act already governs every routine treatment decision.

Students in Northern Ireland should use current Health and Social Care trust procedures and the legal framework that applies to the particular situation.

What Does This Look Like on Placement?

Imagine a patient with a urinary infection and delirium refuses intravenous antibiotics.

The first response should not be, “They are confused, so they have no capacity.”

The team needs to identify the exact decision, give the patient the relevant information in a way they can understand, address communication barriers, and assess whether the delirium is preventing them from understanding, retaining, using or weighing that information, or communicating a choice.

The urgency matters too. If waiting would expose the patient to serious harm, the responsible clinician may need to make a timely decision using the correct legal framework. If the decision can safely wait and the delirium is likely to improve, reassessment later may be appropriate.

Who Makes the Assessment?

Capacity is assessed in relation to the decision being made. In healthcare, the professional responsible for the treatment or care decision will usually be responsible for ensuring that capacity and consent are properly considered. More complex decisions may need senior review, multidisciplinary discussion or specialist legal advice.

As a student nurse, you may notice important evidence. The patient may repeat the same question, be unable to explain the risks in their own words, communicate more clearly with a particular aid, or become much more alert later in the day.

Your role is to report what you observe, support communication, document accurately within your level of responsibility, and involve your practice supervisor or the registered professional. Avoid writing broad labels such as “patient has no capacity” without explaining the specific decision, assessment and evidence.

If the Person Lacks Capacity

Lack of capacity does not mean the person stops having a voice.

They should still be involved as far as possible. Their wishes, feelings, beliefs and values matter. Relatives and carers may provide important information, but “next of kin” does not automatically give someone legal authority to consent for another adult.

The team must also check whether someone holds relevant legal powers, such as a health and welfare Lasting Power of Attorney in England and Wales, or a welfare attorney or guardian in Scotland. The exact document and the powers it grants need to be checked.

The legal decision-making process differs between UK nations, which is why phrases such as “best interests” should not be used as though they are the wording of every framework.

The Bleepbook Takeaway

Do not ask whether the patient “has capacity” in general.

Ask whether they can make this particular decision, at this particular time, after receiving the support they need.

Capacity law is there to protect people from being ignored, controlled or written off. Done properly, it keeps the person involved for as long and as fully as possible.

References

Department of Health Northern Ireland. Mental Capacity Act background.

Legislation.gov.uk. Mental Capacity Act 2005.

National Institute for Health and Care Excellence. Decision-making and mental capacity (NG108).

Nursing and Midwifery Council. The Code.

Scottish Government. Adults with Incapacity (Scotland) Act 2000: principles.