Disability, mental capacity, legal capacity

The Age of Majority Act 1977 (s 3) provides that all persons who turn 18 have legal capacity. This is the statutory basis of the ‘presumption of capacity’.

However, the law has long concerned itself with the possible effect of a person’s disability on their ability to make decisions (Roman Code of Justinian, Table V, Law VII; Prerogativa Regis, 15 Edw 2; William Blackstone 1765, Commentaries on the Laws of England (Clarendon Press).

Article 12 of the UNCRPD challenges this long history. It provides that ‘persons with disabilities have the right to recognition everywhere as persons before the law’, that they ‘enjoy legal capacity on an equal basis with others’, and State Parties are to ‘take appropriate measures to provide access … to the support they may require in exercising their legal capacity’. Clause 4 requires State Parties to ‘ensure that all measures that relate to the exercise of legal capacity provide for appropriate and effective safeguards to prevent abuse’. In 2014 the United Nations (UN) issued its General Comment on Article 12 (see Committee on the Rights of Persons with Disabilities, General Comment No 1 (2014): Equal Recognition before the Law (Article 12 of the Convention on the Rights of Persons with Disabilities), UN Doc CRPD/C/ GC/1 (19 May 2014) paras 11–23.) that makes a distinction between legal capacity and mental capacity.

Victoria has passed laws where mental (decision-making) capacity is defined. The statutes include:

• The Powers of Attorney Act 2014 (‘PA Act’) (see Chapter 8.6: Understanding powers of attorney);

• The Medical Treatment Planning and Decisions Act 2016 (see Chapter 8.5: Guardianship and medical treatment);

• The Voluntary Assisted Dying Act 2017;

• The GA Act (see Chapter 8.5: Guardianship and medical treatment);

• The MHW Act (see Chapter 8.4: Mental illness).

All the definitions involve four elements about the person’s mental functioning. For example, in the GA Act, a person has mental capacity (decision-making capacity) if the person is able to:

1. understand the information relevant to the decision and the effect of the decision;

2. retain that information to the extent necessary to make the decision;

3. use or weigh that information as part of the process of making the decision; and

4. communicate the decision and the person’s views and needs as to the decision in some way, including by speech, gesture or other means.

Each of these Acts is also a little different. This is because capacity is context dependent (e.g. What one needs to be able to understand, retain, weigh up and communicate is different for a decision to refuse medical treatment resulting in death from that necessary to buy a car).

If a person is unable to perform one or any of these four elements in relation to a specific decision, they are deemed to have lost decision-making capacity for that matter. This can have ramifications for their legal agency and legal standing in that they may have a person appointed to make decisions for them, or they may be subject to compulsory psychiatric treatment.

In the General Comments to Article 12, the UN is critical of such functional assessments of mental capacity and the use of them to impose limits on the person’s legal agency and legal standing. In other areas of law, the common law operates to define capacity. For example:

• In relation to contracts, to have capacity means that the person understands the nature and effect of the contract (see Chapter 7.1: How contract law works, for more information);

• In relation to wills, to have capacity means the person understands what a will, is the amount and type of property they have (in general terms) and their obligation to provide for persons such as a spouse, children and certain family members (see Chapter 9.3: Wills, for more information). In support of Article 12 of the UNCRPD, Victoria acknowledges that people with disability may have decision-making capacity if they receive the right support. Victoria has established formal mechanisms to facilitate support:

• Supportive attorneys (see Chapter 8.6: Understanding powers of attorney);

• Support person for medical treatment decisions (see Chapter 8.5: Guardianship and medical treatment);

• Supportive guardians (lifestyle decision-making) (see Chapter 8.5: Guardianship and medical treatment);

• Supportive administrators (financial decisionmaking) (see Chapter 8.5: Guardianship and medical treatment).

In relation to Centrelink and the National Disability Insurance Agency (NDIA), a person is able to appoint a nominee to support them. However, a nominee so appointed can also make decisions for the person. In this way, a nominee has greater powers than supportive appointments noted above. For more information about the role of nominees, see Chapter 5.1: Dealing with social security and Chapter 8.2: Understanding the National Disability Insurance Scheme.

Disability, mental capacity, legal capacity

Chapter: 8.1: Understanding disability and the law

Contributor: Philip Grano, Former Principal Lawyer, Office of the Public Advocate; Naomi Anderson, Legal Practice Manager, Villamanta Disability Rights Legal Service

Current as of: 1 September 2024

Law Handbook Page: 696

Next Section: Protections from abuse and unfair treatment