Mental Capacity Assessment Guide

Mental Capacity Act

Every adult has the right to make his or her own decisions and must be assumed to have capacity to do so unless it is proved otherwise. This means that you cannot assume that someone cannot make a decision for themselves just because they have a particular medical condition or disability.

For example, it can’t be assumed that someone who has suffered a stroke that impaired their ability to communicate, is not capable of making decisions for themselves due to their difficulty to communicate. Similarly, lacking the capacity to manage finances doesn’t mean a lack of capacity to decide on what medical treatment someone needs to receive.

If a person lacked the capacity to make a previous decision, it does not mean that they are not able to make a current decision in question.

It is really important that all practicable steps are taken to determine whether a person can make decisions themselves. This means you should make every effort to encourage and support people to make the decision in question, for themselves, i.e. giving information in an alternative format to make it easier to understand. If lack of capacity is established, it is still important that you involve the person as far as possible in making decisions.

Other examples of ways in which capacity might be maximised include:

  • Use of a sign language.
  • Use of an interpreter (for verbal information).
  • Use of a translator (for written information).
  • Use of communication aids such as picture cards.
  • Using an alternative communication format such as writing instead of speaking.
  • Meeting with an individual on several different occasions to assess or review capacity.
  • Changing a meeting’s location to one that is more suited to the individual’s needs.
  • Changing a meeting’s time to one that is more suited to the individual’s needs.

People have the right not to be treated as lacking capacity merely because they make a decision that others deem ‘unwise’. Everyone has their own values, beliefs and preferences which may not be the same as those of others. It is tempting to consider this solely in terms of risky behaviour, but it is more than this. Someone might understand the risks involved in certain actions and continue regardless. This is not indicative of a lack of capacity. If an ‘unwise’ decision is made, and there is risk involved, support for the individual should continue as assessed appropriate.

Decisions can only be made on behalf of an individual once it has been completely established that they lack capacity in that area. Any decision made on behalf of individuals who lack capacity must be done in their best interests. What they would decide, if they had the capacity to do so should be the basis of the decision that is made. This can be complex and depend on many factors that will maintain the individual’s wellbeing in a holistic manner, with all of their needs taken into account. Consideration must be given to the individual’s past wishes or actions, which includes any form of advance statement or directive that has been put into place.

Any decision made on behalf of an individual who lacks capacity must be done in a manner which is least restrictive to their freedom and basic rights. Any intervention should be assessed, given the circumstances of that particular case. The decision maker must, according to this Principle, consider all options available to them and always contemplate if there is a less restrictive option to the one proposed.


Making a Mental Capacity Assessment

Decision-specific and time-specific

Simplify and frame the decision in the viewpoint/perspective of the person

e.g. family, friends, carers, GP, LPA, Court Deputy

e.g. interpreter, glasses, pen and paper, hearing aids, consider environment, appropriate time, place, past and present wishes-relevant, Advance Decision to Refuse Treatment (ADRT), written advance decisions

In case the patient regains capacity


Functional Test

The person must be able to do all of these things to have capacity for the decision.*

Use appropriate language, give as much information as possible about the treatment/decision to be made. Present clear tangible options, benefits and dis-benefits of each option. Have they got an awareness or insight of the treatment/decision?

Recall salient/important information, saying it in the person’s own words

Are they able to see various sides - pros and cons?

e.g. verbal, non-verbal sign language or using the aids supplied

*Please record your discussion separately from questions 1 to 4, explaining why you have reached that decision.


Diagnostic Test

Give a bit of background if known, and how the impairment/disturbance impacts on behaviour, circumstances

e.g. dementia, learning difficulty, concussion, confusion, delirium, suspected infection (i.e. UTI), unconsciousness, intoxication due to alcohol/substance misuse, dementia, stroke, learning disability/autism, brain injury, neurological disorders and mental illness etc.



Causative Nexus: Is the person’s inability to make the decision at this time caused by the impairment or disturbance in the functioning of the person’s mind or brain?

Assessors must now evaluate the (in)ability to decide and then consider whether this is because of an impairment


Best interests decisions

Section 4-5: You do not necessarily need to have a proper meeting. All relevant circumstances must be considered and, in particular, the following steps must be taken:

Refer when person does not have relatives or friends to advocate for them

State the steps taken to enable the patient to take part in making the decision - using person’s preferred method of communication

State all parties who have been consulted in this decision e.g. person, relatives, friends, advocates, LPA, attorneys, carers

State the details of consideration taken to make the decision i.e. past wishes and feelings, beliefs and values, advanced decisions

On basis of age, diagnosis, behaviour etc.

State details of measures taken to ensure decision made is not influenced by anyone motivated to bring about the patient’s death

e.g. POC vs transfer to care home

Best Interest decision chosen - Reason

Best Interest decision not chosen - Reason