Advance Health Directive and Dementia in Western Australia

The Capacity Window Closes Faster Than Families Expect

A dementia diagnosis doesn't immediately remove your legal capacity to sign an Advance Health Directive (AHD) in Western Australia. But the window between diagnosis and loss of capacity is often shorter than families realise — and once it closes, it's closed permanently.

Under the Guardianship and Administration Act 1990, you must have "full legal capacity" to make an AHD. That means you understand the nature of the document you're signing, the treatment decisions you're making, and the consequences of those decisions. For someone with early-stage dementia, this threshold can still be met. For someone in the moderate or advanced stages, capacity may no longer be present.

The practical urgency is real: delaying can leave less time to complete the documents while capacity is still present.

When Is Someone With Dementia Still Legally Competent?

WA law doesn't use a blanket test. Capacity is assessed on a decision-by-decision basis, meaning someone might have the capacity to make a simple treatment decision but not a complex one. For AHD purposes, the person must demonstrate that they:

1. Understand what an AHD is and what it does
2. Appreciate that their treatment decisions will be binding on medical staff if they lose capacity
3. Can reason through the consequences — for example, understanding that refusing mechanical ventilation means they may die if they can't breathe on their own
4. Can communicate their decision, even if they need assistance expressing it

In early-stage dementia, many people can satisfy all four criteria, particularly with support. A GP familiar with the person's cognitive trajectory can provide a capacity assessment and note it in the medical record. This contemporaneous medical record becomes critical evidence if the AHD is ever challenged.

Getting the Timing Right

The Ideal Window: Immediately After Diagnosis

The strongest position is completing your AHD, Enduring Power of Guardianship (EPG), and Enduring Power of Attorney (EPA) as soon as possible after a dementia diagnosis — while cognitive function is still clearly intact.

At this stage:

• Have your GP assess capacity and document the result
• Complete the AHD's Part 4 (Treatment Decisions) with specific, clear instructions
• Appoint an enduring guardian via an EPG who understands your values and preferences
• Consider whether your EPA should take effect immediately or only upon incapacity

The Narrowing Window: Mild Cognitive Impairment

If someone has been living with mild cognitive impairment (MCI) or early dementia for some time without completing their documents, it's not too late — but speed matters. The same witnessing requirements still apply: two independent adult witnesses, with at least one authorised under the Act.

The Closed Window: Moderate to Advanced Dementia

Once someone can no longer demonstrate the four capacity criteria above, they cannot legally make an AHD in Western Australia. No amount of family insistence or good intentions can override this. If no AHD exists, treatment decisions fall to the statutory hierarchy of treatment decision-makers — the enduring guardian first, then family members in a set order.

What to Include in a Dementia-Specific AHD

A standard AHD covers general treatment preferences, but a person diagnosed with dementia should address specific scenarios that are likely to arise as the condition progresses.

Treatment Decisions to Consider (Part 4)

Artificial nutrition and hydration. In advanced dementia, swallowing difficulties are common. Your AHD should state clearly whether you consent to tube feeding (PEG tube, nasogastric tube) or whether you prefer comfort feeding only — small amounts of food and water offered by hand for comfort rather than nutrition.

Antibiotics for recurrent infections. Pneumonia and urinary tract infections are frequent in advanced dementia. Some people choose to accept antibiotics to treat infections; others prefer comfort measures only, recognising that an infection in advanced dementia may be a natural endpoint.

Hospitalisation. Consider whether you want to be transferred to hospital for treatment, or whether you prefer to remain in your residential facility with palliative support. Hospital transfers in advanced dementia can cause severe distress and disorientation.

CPR and mechanical ventilation. Be specific. "No CPR if I have advanced dementia and no reasonable prospect of meaningful recovery" is clearer than "no heroic measures." Vague instructions give clinicians room to apply the treatment anyway. Our post on common AHD mistakes in WA covers the wording pitfalls.

Values and Preferences (Part 3)

Part 3 of the WA AHD form is optional but becomes critical in dementia planning. This is where you document your quality-of-life thresholds:

• At what point would you consider your quality of life unacceptable? (Unable to recognise family? Unable to communicate? Unable to feed yourself?)
• What matters most to you — comfort, dignity, being at home, being with family?
• Are there cultural or religious considerations that should guide treatment decisions?

These statements aren't legally binding in the same way as Part 4 treatment decisions, but they give your enduring guardian and treating doctors the context they need to make decisions your AHD doesn't specifically address.

The Enduring Power of Guardianship Is Essential

An AHD can't anticipate every medical scenario. For someone with dementia, an Enduring Power of Guardianship is arguably even more important than the AHD itself, because the guardian will need to make ongoing decisions as the condition progresses.

Your enduring guardian will handle:

• Consent to or refusal of treatments not covered by your AHD
• Decisions about accommodation — whether to move into residential aged care, and which facility
• Choices about support services, therapies, and daily care

Choose someone who understands dementia's trajectory, who can advocate firmly with hospital staff, and who won't be paralysed by guilt when difficult decisions arise. If your first choice can't serve, a substitute guardian ensures there's always someone authorised to act.

Protecting the AHD From Challenge

Dementia diagnoses make AHDs more vulnerable to legal challenge — typically from a family member who disagrees with the treatment decisions and argues the maker lacked capacity when they signed.

Protective steps:

1. Get a contemporaneous capacity assessment from your GP and ask them to record the assessment in your medical file.
2. Complete the AHD in the presence of two independent adult witnesses, at least one authorised under the Act, who know you well — but who are not appointed as your guardian. Their testimony about your understanding carries weight.
3. Don't delay. The further the signing date is from the diagnosis date, the harder it becomes to argue that capacity was intact.
4. Cross out unused optional parts of the AHD form, as required by the WA Department of Health's instructions. Leaving sections blank creates ambiguity that can be exploited in a challenge.

What If the Window Has Already Closed?

If your family member already lacks the capacity to sign an AHD, the legal options narrow considerably. Treatment decisions will be made by the first available person on the statutory hierarchy of treatment decision-makers. If no family member is suitable or willing, the State Administrative Tribunal can appoint a guardian — potentially the Public Advocate.

In aged-care settings, the facility will initiate a Goals of Patient Care (GoPC) discussion with the family to establish treatment ceilings for the current admission period. This isn't a substitute for an AHD — it's a clinical tool, not a legal document — but it provides some framework for decision-making.

Don't Wait for a Crisis

The Western Australia Advance Directive & Living Will Kit includes treatment decision worksheets designed to help you think through dementia-specific scenarios before completing Part 4 of the statutory form. It also covers the witnessing requirements, GP consultation steps, and My Health Record upload process that ensures your directive is accessible to any hospital in Australia.

If dementia is on the radar — your own diagnosis, a family history, or a parent showing early signs — the time to act is now, not after the next cognitive assessment.

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