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Capacity Assessments

Capacity Assessments

The Mental Capacity Act (2005) is designed to protect and empower people who may lack the mental capacity to make their own decisions about their care and treatment. It applies to people aged 16 and over.

It covers decisions about day-to-day things like what to wear or what to buy for the weekly shop, or serious life-changing decisions like whether to move into a care home or have major surgery.

Examples of people who may lack capacity include those with:

  • dementia
  • a severe learning disability
  • a brain injury
  • a mental health illness
  • a stroke
  • unconsciousness caused by an anaesthetic or sudden accident

But just because a person has one of these health conditions does not necessarily mean they lack the capacity to make a specific decision. Someone can lack capacity to make some decisions (for example, to decide on complex financial issues) but still have the capacity to make other decisions (for example, to decide what items to buy at the local shop).

The MCA also allows people to express their preferences for care and treatment, and to appoint a trusted person to make a decision on their behalf should they lack capacity in the future.

When should mental capacity be assessed in a person with dementia?

You must always assume that a person is able to make a decision for themselves, until it is proved that they can’t.

A person’s capacity may be questioned if there is doubt about whether they can make a particular decision. This could happen if:

  • the person’s behaviour or circumstances are making those around them doubt whether the person has capacity to make a particular decision
  • a professional says they have doubts about the person’s ability to make the decision – this could be a social worker or the person’s GP
  • the person has previously been unable to make a decision for themselves.
  • To work out whether a person has capacity to make a decision, the law says you must do a test (often called an assessment) to find out whether they have the ability to make the particular decision at the particular time.

Before the person is tested, they should be given as much help as possible to make the decision for themselves. Those who are supporting the person to make the decision should find the most helpful way to communicate with the person. This may mean:

  • trying to explain the information to them in a different way
  • helping them to understand the ideas that are involved in making the decision
  • breaking down information into small chunks.

Who Can Carry Out A Mental Capacity Assessment?

Ideally the assessment should be carried out by someone who is involved in supporting the person being tested and will be responsible for making a decision if the person is unable to do so.

This is usually a relative, close family friend, or a mental capacity solicitor, but could include any of the following:

  • Carer
  • Social Worker
  • Support Workers
  • Occupational Therapist
  • GP
  • Nurse
  • Court-Appointed Deputy

Whoever carries out the test is under an obligation to abide by the principles found in Section 1 of the Mental Capacity Act 2005, and to undertake a balance of probabilities:

  • A person must be assumed to have capacity unless it is established that they lack capacity.
  • A person is not to be treated as unable to make a decision unless all practicable steps to help him to do so have been taken without success. Examples of this would be the use of communication aids, different methods of explanation and undertaking the assessment at the best time of day for that person.
  • A person is not to be treated as unable to make a decision merely because he makes an unwise decision. If the person has capacity to make a decision they should be supported to do so despite how unwise others may find it.
  • A decision made on behalf of a person who lacks capacity must be done in his best interests.
  • Before the decision is made regard must be had to achieving the outcome in a way that is as least restrictive of the person’s rights and freedom as possible.

What Happens After Assessment?

If someone lacks the capacity to make a decision and the decision needs to be made for them, the MCA states the decision must be made in their best interests.

The MCA sets out a checklist to consider when deciding what's in a person's best interests. The assessor should:

  • encourage participation – do whatever's possible to permit or encourage the person to take part
  • identify all relevant circumstances – try to identify the things the individual lacking capacity would take into account if they were making the decision themselves
  • find out the person's views – including their past and present wishes and feelings, and any beliefs or values
  • avoid discrimination – do not make assumptions on the basis of age, appearance, condition or behaviour
  • assess whether the person might regain capacity – if they might, could the decision be postponed?

It's vital that consultation takes place with others for their views about the person's best interests – this can include but is not limited to:-

  • anyone previously named by the individual
  • anyone engaged in caring for them
  • close relatives and friends
  • any attorney appointed under a Lasting Power of Attorney*
  • any deputy appointed by the Court of Protection to make decisions for the person


A capacity assessment not only protects individuals by law, it can also provide peace of mind for family/carers responsible for the welfare of loved ones.

*You can grant a Lasting Power of Attorney (LPA) to another person (or people) to enable them to make decisions about your health and welfare, or decisions about your property and financial affairs.

Separate legal documents are made for each of these decisions, appointing one or more attorneys for each. Powers of attorney can be made at any time when the person making it has the mental capacity to do so, provided they're 18 or over.

Capacity Assessment Service at the Sloane Court Clinic

At the Sloane Court Clinic, our capacity assessment service is led by Dr Ruth Cairns, Consultant Psychiatrist. Dr Cairns has 22 years’ experience as a psychiatrist, twelve at consultant level, and is trained as a consultant in both general adult and old age psychiatry. During her training she worked in academic posts and published work around the assessment of mental capacity and the Deprivation of Liberty Safeguards.

She has retained this research interest and was involved in the recent Mental Health Act reform, advising on the interface between the Mental Health and Mental Capacity Acts. She specialises in working with older adults and has considerable clinical experience of mental capacity assessment and working within the MCA framework for patients with dementia and other mental health conditions.


Our Capacity Assessment service is led by Dr Ruth Cairns.

DrRuth Cairns

Contact and Appointments

If you are seeking an appointment with a psychiatrist, you should discuss this first with your GP to obtain a referral. Referrals are also accepted from clinical psychologists and counsellors.

Once you have your referral, please do contact us via our Enquiry Form and one of our team will be in touch without delay.

Overseas referrals are warmly welcomed. We do also see individuals without a family doctor (GP), and we can help you find a private or NHS family doctor.