Can a Person Who Is Confused or Hallucinating Still Make a Valid Will?

A recent South Australian Supreme Court decision illustrates how difficult questions of testamentary capacity can become when a Will is prepared near the end of someone’s life. The deceased signed his Will in hospital after being told that he might have only days or weeks to live. He had experienced hallucinations and periods of obvious confusion, yet the Court found that he understood what he was doing and upheld the Will.

The decision does not mean that confusion or hallucinations can be ignored. They may provide a proper basis for questioning a Will. It does show, however, why capacity must be assessed at the relevant time and against the particular decision the person was making.

A person does not necessarily lose the ability to make a valid Will because they are gravely ill, taking strong medication, confused at times or even experiencing hallucinations. The decisive question is whether they have testamentary capacity when they give their instructions and sign the Will.

What is testamentary capacity?

Testamentary capacity is the mental ability required to make a valid Will.

In broad terms, a person making a Will must be capable of understanding:

• that they are making a Will and what the Will will do;
• the general nature and extent of the property they are disposing of;
• the people who may reasonably have a claim upon their estate; and
• how to evaluate those competing claims and make a deliberate choice, free from any relevant disorder or delusion affecting that decision.

The law is concerned with capacity. It is not always necessary to prove that the person actually considered every asset and every possible beneficiary in detail. The question is whether they had the ability to understand and evaluate those matters.

Capacity is also decision-specific. Someone may be capable of making an ordinary day-to-day decision but not a complex financial decision. Conversely, illness or impairment in one area does not automatically establish that the person was incapable of making a Will.

Does confusion or hallucination mean that a person cannot make a Will?

Confusion or hallucinations may raise concerns about capacity, but neither automatically prevents a person from making a valid Will.

A person’s mental state can fluctuate. They may be confused or drowsy at one time and lucid at another. The Court may therefore consider whether the Will was made during a period in which the person could understand the relevant information, retain it long enough to consider it and make a reasoned decision.

This is sometimes described as a lucid interval. It does not mean that a brief appearance of alertness will always be enough. A pleasant conversation or the ability to recognise family members may reveal little about whether someone can weigh competing claims upon an estate. The nature, quality and duration of the person’s interactions all matter.

What happened when the Will was made in hospital?

The deceased was admitted to hospital on his 70th birthday with advanced cancer. He was told the following day that no further treatment was available and, soon afterwards, that he might have only days or weeks to live.

He had no spouse or children. His estate principally consisted of his home, which he had inherited from his parents. His closest living relatives were two cousins, but he also had a close friend of about 30 years whom he had assisted financially in the past.

Four days before the Will was signed, the deceased participated in the preparation of an informal note about his affairs. It contemplated a five-way division involving his friend, his cousins and two of their children. No one argued that the note was itself a Will, but it later became part of the evidence about what he had been considering.

A solicitor attended the hospital several days later. She took instructions and prepared a temporary Will in the morning, then returned with a colleague that afternoon with a more formal document. The deceased signed the Will, leaving his estate in equal shares to his friend and his two cousins. He died eight days later.

Why was the Will challenged?

The deceased’s cousins challenged the Will because they contended that he lacked testamentary capacity. If the Will failed and there was no earlier valid Will, the estate would be distributed under the rules of intestacy, under which the close friend would apparently receive nothing.

There was no allegation of undue influence. It was also accepted by the end of the case that the deceased understood what a Will was and understood the nature of his estate. The central question was narrower: could he evaluate the respective claims of the people in his life and make a deliberate choice between them?

That concern was not fanciful. Hospital records showed that the deceased experienced visual and auditory hallucinations. At various times he was confused, inattentive or drowsy. Two geriatricians who later reviewed the records expressed opinions that raised questions about his cognitive functioning.

Once a real doubt was raised, the person seeking to uphold the Will had to provide evidence capable of satisfying the Court that the deceased nevertheless had testamentary capacity.

What evidence showed that the deceased had capacity?

The Court considered all of the evidence surrounding the deceased’s behaviour and decision-making, rather than treating any diagnosis, symptom or medical opinion as decisive.

There were significant periods when he was not hallucinating, confused or drowsy. During those periods, he could absorb information, retain it, reflect upon alternatives and communicate decisions. In the days surrounding the Will, he discussed the payment of bills, made decisions about treatment and palliative care, considered arrangements for his personal belongings and explained aspects of his intended Will.

The solicitor described him as responsive, lucid and decisive when she took instructions. When she returned later that day, he remembered what they had discussed. The following day, he told a doctor that he had completed his Will.

The distribution was also understandable. His friend had been close to him for decades and he had a history of helping her financially. His cousins were his closest relatives. Although he had considered a different division several days earlier, the evidence showed that he had time to reflect and had not simply forgotten the other people who might have expected to benefit.

The Court was satisfied that his condition fluctuated and that, during significant lucid periods, he retained the ability to make a deliberate assessment of how his estate should be distributed. The Will was upheld.

Does a medical diagnosis decide whether a Will is valid?

A diagnosis may be important evidence, but it does not by itself decide whether a person had testamentary capacity.

In this case, medical experts considered whether brain imaging and the deceased’s medical history suggested an underlying cognitive impairment. The Court accepted that a scan alone could not establish cognitive incapacity. The deceased’s actual behaviour and functioning remained critical.

The same principle can apply to conditions such as dementia, delirium or other cognitive impairment. The label attached to a condition is not the legal test. The evidence must show how the condition affected the person’s ability to understand and decide at the time the Will was made.

That is why apparently similar cases can produce different results. In The Last Will That Wasn’t: How Two ‘Valid’ Wills Were Found to Be Invalid, later Wills were rejected where the evidence of cognitive decline, unexplained changes and problems in the preparation process left the Court unsatisfied that the deceased had capacity or knew and approved their contents.

How can a late or urgent Will be protected from challenge?

A carefully managed Will-making process can create valuable evidence of the person’s wishes and capacity, particularly where the Will is prepared urgently or in hospital.

Depending on the circumstances, a solicitor may need to speak with the person alone, use open questions, explore their family and assets, ask why they wish to distribute the estate in a particular way and keep a detailed record of the answers. Medical information or an assessment may also be appropriate where there is genuine doubt about capacity.

The solicitor’s process in this case was not beyond criticism. The deceased was not always interviewed entirely away from beneficiaries, his reasons were not explored as fully as they might have been and aspects of the record-keeping could have been better. Those shortcomings did not invalidate the Will, but they demonstrate how gaps in the process can make a later dispute more difficult and expensive.

A medical certificate is not a guarantee that a Will is valid, just as the absence of one does not necessarily make it invalid. What matters is whether the evidence addresses the legal test and records the person’s own understanding and decision-making.

Can family members challenge a Will because it was made shortly before death?

A Will is not invalid merely because it was signed shortly before the person died, but the timing and surrounding circumstances may justify careful investigation.

Relevant evidence may include the deceased’s medical records, medications, solicitor’s file notes, previous Wills, communications with family and friends, the reasons for any significant change, and the involvement of anyone who benefited from the new Will.

A challenge to the validity of a Will is different from a claim that a valid Will failed to make adequate provision for someone. Our page on challenging a Will explains the principal grounds upon which validity may be disputed and the steps that may be available before probate is granted.

Anyone considering a challenge should obtain advice promptly. A caveat should not be lodged or maintained without proper grounds, and an unsuccessful dispute can carry significant costs consequences.

What should you do if capacity may become an issue?

Making or updating a Will before illness becomes critical is the best way to reduce uncertainty, but a person should not assume that it is simply too late because they are in hospital or receiving palliative care.

Urgent legal advice may allow the person’s wishes to be recorded while they still have capacity and may enable appropriate safeguards to be put in place. Delay can leave the family with an intestacy or an outdated Will that no longer reflects what the person wanted.

If someone has died and there are concerns about a late Will, periods of confusion, possible pressure from a beneficiary or unexplained changes, the evidence should be reviewed before conclusions are drawn. The fact that the deceased was sometimes lucid will not necessarily answer the question, but nor will evidence that they were sometimes confused.

Each case turns on its own facts. Early advice can help determine whether there is a proper basis to challenge the Will, how it might be defended, and what steps should be taken before the estate is administered.

Case: Rogers & Anor v Rogers [2026] SASC 115