Mental Disability in Guardianship Law: A Critical Distinction Between Administration and Guardianship

Introduction: A Case of Communication Barriers

The recent Western Australian State Administrative Tribunal decision in K [2025] WASAT 15 highlights a crucial but often overlooked distinction in guardianship law: the different thresholds for appointing an administrator versus a guardian. The case involved K, a 34-year-old Aboriginal man who was deaf and mute from birth. Despite being assessed at age 6 as "a very capable and enthusiastic learner, held back only by his linguistic needs," K reached adulthood without developing conventional communication skills. He communicated using a combination of Aboriginal hand signs, family-developed signs, and some Auslan, leaving him functionally illiterate and with significant communication barriers. Despite finding that K was unable to manage his financial affairs and was incapable of looking after his own health and safety, the Tribunal came to different conclusions regarding the need for administration versus guardianship orders.

The Critical Distinction: Mental Disability Requirements

The most significant insight from K [2025] WASAT 15 is the distinction between the legislative requirements for administration versus guardianship orders:

Administration Orders

Under s 64(1)(a) of the Guardianship and Administration Act 1990 (WA) (GA Act), the Tribunal can only make an administration order if satisfied that the person is "unable, by reason of a mental disability, to make reasonable judgments in respect of matters relating to all or any part of their estate."

This means two elements must be established:

  1. The person has a mental disability

  2. The mental disability causes the person's inability to make reasonable judgments about financial matters

Guardianship Orders

By contrast, under s 43(1)(b) of the GA Act, the Tribunal may appoint a guardian if satisfied that the person:

  1. Is incapable of looking after their own health and safety; or

  2. Is unable to make reasonable judgments in respect of matters relating to their person; or

  3. Is in need of oversight, care or control in the interests of their own health and safety or for the protection of others

Crucially, there is no explicit requirement that these conditions be caused by a mental disability. The focus is on the functional incapacity itself, regardless of its cause.

The Definition of "Mental Disability"

The GA Act defines "mental disability" in s 3(1) as including "an intellectual disability, a psychiatric condition, an acquired brain injury and dementia." As explained in FY [2019] WASAT 118, this is an inclusive definition rather than an exhaustive one.

In K [2025] WASAT 15, the Tribunal elaborated on the six key features of "mental disability" as established in FY [2019] WASAT 118:

  1. The ordinary meaning of "mental disability" contemplates that a person's mind is affected by an impairment, incapacity, or inability to function in a manner considered normal.

  2. The definition encompasses recognized medical conditions that may result in impairment of mental functioning.

  3. An "intellectual disability" specifically refers to impairment in a person's power to understand or reason.

  4. There is no requirement that the mental disability be permanent - some may be transient.

  5. No precise degree of mental disability is required - there is no medical or scientific benchmark that must be met.

  6. A finding of mental disability does not necessarily require the existence of a recognized medical condition or disorder - the underlying cause may not be entirely clear or diagnosed, but the existence of the mental disability may be beyond doubt.

Application in K's Case: Different Outcomes for Administration vs. Guardianship

In K's case, the Tribunal reached different conclusions regarding administration and guardianship:

Administration Application Dismissed

The Tribunal found that K had a substance use disorder, which qualified as a mental disability. The Tribunal also found that K was unable to manage his own financial affairs. However, the application for administration was dismissed because the Tribunal was not satisfied that K's inability to manage his finances was caused by his substance use disorder.

As Member Haigh stated: "On the evidence before me I am not satisfied that K is unable, by reason of a mental disability, to make reasonable judgments in respect of matters relating to all or any part of his estate. I am not satisfied that the criterion in s 64(1)(a) is met."

Instead, K's financial difficulties appeared to stem primarily from his communication barriers, financial exploitation by others, and his anger and frustration at these circumstances.

Guardianship Application Granted

By contrast, the Tribunal granted the guardianship application, appointing the Public Advocate as limited guardian with authority over treatment decisions, services, restrictive practices/restraint, and accommodation.

The Tribunal found that K was incapable of looking after his own health and safety, unable to make reasonable judgments in respect of matters relating to his person, and in need of oversight, care or control in the interests of his own health and safety and for the protection of others.

Importantly, these findings did not require establishing that K's incapacity was caused by a mental disability. The Tribunal was concerned with K's functional capacity to make personal welfare decisions, regardless of the cause of that incapacity.

The Nexus Requirement for Administration Orders

The case clearly illustrates the importance of the causal nexus requirement for administration orders. As explained in FY [2019] WASAT 118 at [73], "an inability to make reasonable judgments in relation to one's estate does not, of itself, constitute a sufficient basis for the making of an administration order."

The use of the phrase "by reason of" in s 64(1)(a) implies a relationship of cause and effect between a mental disability and the person's inability to make reasonable judgments. The Tribunal noted that this phrase equates to "because of" and "due to," requiring the application of ordinary causation principles.

This strict causation requirement reflects the more intrusive nature of administration orders, which remove a person's legal capacity to make financial decisions and transfer that authority to another person.

Distinguishing Between Communication Barriers and Mental Disability

K [2025] WASAT 15 highlights the importance of distinguishing between communication barriers and mental disability. The Tribunal noted that K's communication difficulties "give rise to practical difficulties in making decisions in respect of financial matters, however they do not of themselves render a person incapable of making reasonable judgments about financial matters."

This distinction is crucial for practitioners working with clients who have sensory impairments or come from culturally and linguistically diverse backgrounds. Communication barriers may create practical obstacles that make decision-making more challenging, but these obstacles may be overcome with appropriate support strategies. They do not necessarily constitute a mental disability that causes an inability to make reasonable judgments.

Practical Implications for Legal Practitioners

This case offers several important lessons for practitioners in guardianship and administration law:

  1. Different evidentiary requirements: For administration applications, practitioners must gather evidence not just of a mental disability and financial incapacity, but of a causal relationship between them. For guardianship applications, the focus is on establishing functional incapacity in personal welfare matters, regardless of cause.

  2. Consider alternatives to administration: When a client is struggling with financial management due to communication barriers rather than a mental disability causing impaired judgment, alternatives to administration should be explored.

  3. Guardianship may be appropriate even when administration is not: As demonstrated in K's case, a person may need a guardian for personal welfare decisions even if they do not require an administrator for financial matters.

  4. Careful assessment of diagnostic evidence: Courts require clear and cogent evidence to establish that a person has a mental disability. In GC and PC [2014] WASAT 10 at [36] (quoted in MH [2022] WASAT 74 at [130]-[131]), the Tribunal emphasized the need for such evidence to displace the presumption of capacity.

Conclusion

K [2025] WASAT 15 provides a valuable reminder of the critical distinction between the requirements for administration versus guardianship orders. While administration requires that a mental disability causes an inability to make reasonable financial judgments, guardianship focuses on functional incapacity in personal welfare matters without an explicit causation requirement.

This distinction reflects the different nature and purposes of these orders and ensures that administration orders, which involve significant restrictions on financial autonomy, are only made when truly necessary and when the statutory causation requirement is met.

For lawyers, medical professionals, and families navigating the guardianship system, understanding this distinction is essential to proper application of the law and to ensuring that individuals receive appropriate support while maintaining maximum autonomy.