Introduction
The decision in RN [2025] WASAT 46 provides guidance on the meaning and application of "mental disability" as a prerequisite for appointing an administrator under section 64 of the Guardianship and Administration Act 1990 (WA).
In this case, the State Administrative Tribunal considered whether a woman in her 60s who had fallen victim to a sophisticated international romance scam, losing at least $1 million over seven years, had a mental disability warranting the appointment of an administrator.
The Tribunal ultimately found that RN's combination of histrionic personality disorder and low average IQ constituted a mental disability within the meaning of the Act, with her abnormal susceptibility to exploitation being a significant symptom or manifestation of this disability.
The Statutory Framework
To appoint an administrator under the Guardianship and Administration Act 1990 (WA), section 64(1)(a) requires the Tribunal to be 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" (RN [2025] WASAT 46 at [31]).
This provision establishes a two-stage test: first, the existence of a mental disability, and second, a causal connection between that disability and the inability to make reasonable judgments about one's estate.
The term "mental disability" is defined inclusively in section 3 of the Guardianship and Administration Act 1990 (WA) to include "intellectual disability, a psychiatric condition, dementia, and acquired brain injury" (RN [2025] WASAT 46 at [32]). However, as the Full Tribunal clarified in FY [2019] WASAT 118, this definition is not exhaustive.
The Meaning of Mental Disability
The Full Tribunal's decision in FY [2019] WASAT 118 provides the authoritative interpretation of "mental disability" in Western Australian guardianship law. As cited in RN [2025] WASAT 46 at [32], the Full Tribunal held that:
"The ordinary meaning of the term 'mental disability' in the GA Act thus contemplates that a person's mind is affected by an impairment, incapacity or inability to function in a manner, or within a range, considered normal, or which is objectively measurable. A mental disability may manifest in a variety of ways, including as a disturbance or limitation in a person's thought processes or their cognitive ability, in their perceptions of reality, emotions or judgments, in disturbed behaviour or in learning difficulties" (FY [2019] WASAT 118 at [27]).
Importantly, the Full Tribunal emphasized that "the definition of 'mental disability' does not require any precise degree of mental disability, measured by reference to some medical or scientific benchmark" (FY [2019] WASAT 118 at [31], cited in RN [2025] WASAT 46 at [32]). This recognizes that mental ability exists along a spectrum, with various aspects of cognitive functioning including "the speed and ease of information processing, problem solving, reasoning, and memory" (FY [2019] WASAT 118 at [31]).
Furthermore, the Full Tribunal noted that while a mental disability may be "referrable to the existence of one, or a combination of more than one, identified medical conditions," in other cases "the underlying cause of a person's mental disability may not be entirely clear, or susceptible to a particular medical diagnosis, but the existence of the mental disability may be beyond doubt" (FY [2019] WASAT 118 at [32], cited in RN [2025] WASAT 46 at [32]).
Application to Complex Cases
The decision in RN [2025] WASAT 46 demonstrates how the Tribunal approaches cases where mental disability arises from a combination of factors rather than a single, clearly diagnosed condition. The Tribunal found that RN had a mental disability comprising two core elements:
First, a histrionic personality disorder, which the Tribunal described by reference to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, as "an enduring pattern of inner experience and behavior that deviates markedly from the expectations of the individual's culture, is pervasive and inflexible, has an onset in adolescence or early adulthood, is stable over time, and leads to distress or impairment" (RN [2025] WASAT 46 at [35]). The Tribunal noted specific features including high suggestibility, being easily influenced by others, and being "overly trusting, especially of strong authority figures whom they see as magically solving their problems" (RN [2025] WASAT 46 at [36]).
Second, a low average IQ that "contributes to her poor judgment and limited financial literacy" (RN [2025] WASAT 46 at [39]). The Tribunal emphasized that cognitive screening tools like the Montreal Cognitive Assessment or Rowland Universal Dementia Assessment Scale may not capture impairments in higher-order executive functions, noting that "being able to make a deliberated, informed decision after weighing up the pros and cons of different options, which is the type of decision-making the Tribunal is concerned with, falls into this highest category of executive functions" (RN [2025] WASAT 46 at [41]).
The Tribunal also identified "a further aspect of RN's mental disability, or a symptom of it," namely her "abnormal susceptibility to being exploited or coerced, and her inability to identify when it is occurring" (RN [2025] WASAT 46 at [43]). Importantly, the Tribunal stressed that "the fact that a person is a victim of a scam does not of itself mean that a person has a mental disability" but found that RN demonstrated "a pattern, over the course of her life, of being persuaded or pressured into making decisions that are not in her best interests" (RN [2025] WASAT 46 at [43]). This susceptibility to exploitation was viewed as a manifestation of the underlying mental disability rather than a separate constituent element.
Distinguishing Temporary Conditions
The Tribunal in RN [2025] WASAT 46 also addressed the distinction between mental disability and temporary emotional responses. While RN was diagnosed with an adjustment disorder, defined as "an emotional or behavioural response to an identified stressor, with such distress being out of proportion to the severity or intensity of the stressor," the Tribunal specifically noted that it "have not relied on this diagnosis as a basis for RN's mental disability" because adjustment disorders are temporary and symptoms do not persist beyond six months after the stressor concludes (RN [2025] WASAT 46 at [48]-[49]).
The Tribunal concluded: "I am satisfied, and I find, that RN's condition falls within the meaning of 'mental disability' as described in FY, based on the most comprehensive and recent assessment of RN that was performed by Dr F. I am satisfied that the existence of the mental disability was clearly established by the evidence and is referable to the combination of the personality disorder, her low average IQ and her abnormal, and long-standing, susceptibility to being exploited" (RN [2025] WASAT 46 at [50]). This formulation suggests that while the susceptibility to exploitation forms part of the overall picture, the core mental disability comprises the personality disorder and low IQ, with the exploitation vulnerability being a significant manifestation of these underlying conditions.
Conclusion
The decision in RN [2025] WASAT 46 reinforces that determining whether a person has a mental disability for the purposes of the Guardianship and Administration Act 1990 (WA) requires a holistic assessment of their cognitive functioning and decision-making capacity. The Tribunal's approach demonstrates that mental disability can arise from a combination of factors that collectively impair a person's ability to make reasonable judgments, even where no single factor might be sufficient on its own. Importantly, the decision clarifies that vulnerability to exploitation, while not itself constituting a mental disability, can be a significant symptom or manifestation of underlying cognitive or psychiatric conditions. This nuanced approach ensures that vulnerable individuals who genuinely require protection can access the safeguards provided by the Act, while maintaining the high threshold required to override personal autonomy through the appointment of an administrator.