Judging Mental Capacity

Goh Eng Cher

In the award-winning Broadway musical Hamilton, George Washington says to Alexander Hamilton, "Dying is easy, young man. Living is harder." Living is hard, and it is even harder when one's mental capacity to make decisions about one's own affairs and care is in doubt.

Whether a person has mental capacity is often considered a question for medical practitioners to answer. Most, if not all, of the standard trust templates used by licensed trust companies in Singapore include provisions on incapacity that typically require the incapacity of an individual to be certified by one or more medical practitioners. It is not unusual for medical practitioners to have to attest to whether a testator (the maker of a will) has the capacity to execute a will, especially where the testator is elderly or suffers from some illnesses.

Nonetheless, the assessment of mental capacity is ultimately a question of law. Courts have regularly been asked to determine whether a person has the requisite mental capacity to execute a will or to enter into a transaction. In ascertaining whether a person has mental capacity, courts do not rely solely on expert medical opinion, but have instead developed rules for ascertaining capacity, which have been largely codified in the Mental Capacity Act 2008 (MCA).1

This article aims to provide a short overview of the test under the MCA for mental capacity, and to discuss the role the medical profession plays in the application of this test.

Principles of the MCA

Losing one's mental capacity takes away a person's ability to make decisions for himself or herself, and therefore severely undermines such person's autonomy and freedom. As such, the MCA sets out five principles that underlie the application of the Act:

  1. A person must be assumed to have capacity unless it is established that the person lacks capacity;
  2. A person is not to be treated as unable to make a decision unless all practicable steps to help the person to do so have been taken without success;
  3. A person is not to be treated as unable to make a decision merely because the person makes an unwise decision;
  4. An act done, or a decision made, under the MCA for or on behalf of a person who lacks capacity must be done, or made, in the person's best interests; and
  5. Before the act is done, or the decision is made, regard must be had to whether the purpose for which it is needed can be effectively achieved in a way that is less restrictive of the person's rights and freedom of action.

These reflect a fundamental principle that mental capacity is not to be lightly taken away, and that even if a person loses mental capacity, decisions made on such person's behalf should be made in a way that causes the least harm to that person's rights and freedom.

The test for mental capacity

The test for mental capacity under the MCA is stated in section 4(1), that "a person lacks capacity in relation to a matter if at the material time the person is unable to make a decision for himself or herself in relation to the matter because of an impairment of, or a disturbance in the functioning of, the mind or the brain".

Section 5 goes on to state that a person is unable to make a decision for himself or herself if the person is unable to:

  1. Understand the information relevant to the decision;
  2. Retain that information;
  3. Use or weigh that information as part of the process of making the decision; or
  4. Communicate his or her decision whether by talking, using sign language or any other means.

Other provisions of section 4 state that it does not matter whether the impairment or disturbance is permanent or temporary, and a lack of capacity cannot be established merely by reference to a person's age or appearance, or to a condition of such person, or an aspect of such person's behaviour, which might lead others to make unjustified assumptions about the person's capacity.

These provisions reflect the principle that capacity is both decision- and time-specific. In other words, the query to be made is: does that person have the capacity, at that particular time, to make a decision on this matter? It is important to note that just because a person makes an unwise decision does not mean that he or she is unable to make a decision.

The above is supported by the case law that has developed around testamentary capacity, ie, whether the testator has the requisite capacity to make such a will. In George Abraham Vadakathu v Jacob George,2 the testator was diagnosed with schizophrenia in 1957 and passed away in 2006. In ascertaining whether he had the requisite capacity to make a will, the court looked at the (conflicting) evidence given by medical experts as to his mental capacity, based on medical reports done before and after the will was executed. In Chee Mu Lin Muriel v Chee Ka Lin Caroline,3 the testator was suffering from dementia when she executed her last will and while there was a multitude of medical reports on both sides as to her mental capacity, the court noted that there was no contemporaneous medical diagnosis that the testator's medical condition would have incapacitated her testamentary competence at the making of the will.

These cases therefore recognise that a person may have fluctuating capacity, and what is relevant is whether at the time the decision (to execute the will) was made, that he/she, despite existing mental illnesses, had sufficient capacity to make that decision.

Role of medical professionals

The test for capacity under section 4(1) MCA has been held by the courts to comprise two components: a functional component, which is that the person is unable to make a decision, and a clinical component, which is that this inability to make a decision is caused by a mental impairment. This was first enunciated by the Singapore Court of Appeal in Re BKR as follows:4

"[T]he test for capacity in s 4(1) MCA may be thought of as having a functional and a clinical component – the functional aspect is that P must be unable to make a decision, and the clinical aspect is that this inability must be caused by a mental impairment. It is not difficult to see that we require the assistance of expert evidence when addressing the clinical component of the test: we need medical professionals to tell us whether P has a mental impairment based on the observable symptoms and any other diagnostic tools available, and if so, what that impairment is, and what effect it has on P's cognitive abilities. But as to the functional component, it is in our judgement a question for us to grapple with leaving perhaps a limited scope for the involvement of the medical experts."

While this division of the test for capacity into functional and clinical components may, at first glance, appear to simplify matters for medical professionals who only need to determine whether a person has a mental impairment, and the effect that impairment has on that person's cognitive abilities, this is not as simple in practice. After all, it is not possible for parties to go to court every time an issue arises to determine whether a person has the requisite mental capacity to make a decision. The medical profession, like the legal profession, often finds itself in the middle of messy situations involving very personal and important questions on a person's autonomy and freedom to make decisions (or not make them, as the case may be), and are looked upon to exercise their professional judgement in guiding patients, clients and their families on how to proceed. Their professional views and opinions could be subsequently questioned, either in court or outside court.

It is therefore important for medical professionals in such situations to maintain contemporaneous and comprehensive records about the patient's medical condition and how it supports the medical practitioner's conclusion about the patient's capacity at a specific point in time. While this is in any case a matter of good professional practice, it becomes particularly important where the medical practitioner is aware of complicated family dynamics that may lead to disputes where the medical practitioner is called upon to give evidence.

It is hopefully rare that a medical practitioner gets caught up in courtroom drama, but medical practitioners should nonetheless remember that issues of mental capacity do not arise only where there is a dispute among family members over a patient's assets. Mental capacity can also be an issue in other aspects of medical practice. For example, there can be situations where patients defer to their families on decisions relating to their medical care and treatment, to the extent that family members are the ones having in-depth discussions with the medical team. While there can be very good reasons for such arrangements, it is important for the medical practitioner to keep in mind the first two principles under the MCA as stated above. A medical practitioner should make sure that a patient with capacity understands the proposed medical treatment plan and that he/she (not just the family) is agreeable to such plan.

  1. Mental Capacity Act 2008. Available at: https://bit.ly/3rYAfSf.
  2. Abraham Vadakathu v Jacob George [2009] SGHC 79.
  3. Chee Mu Lin Muriel v Chee Ka Lin Caroline [2010] SGCA 27.
  4. Re BKR [2015] SGCA 26.

Goh Eng Cher is co-head of Allen & Gledhill LLP's Private Wealth Practice. Her principal areas of practice are trusts, private wealth and tax. She has extensive experience on succession and estate planning for high net worth and ultra-high net worth individuals and their families.