The increasing prevalence of dementia in the UK is not only reshaping the health and social care landscape but also exerting a visible influence on legal practice, particularly in the area of contested probate. Dementia now affects nearly one million people across the country, up from 850,000 in 2015. University College London forecasts that this number will rise by over 70% by 2040, reaching more than 1.7 million. Globally, dementia cases are expected to triple by 2050. These statistics are more than just demographic projections; they reflect a societal shift with practical consequences for how wills are made, how they are interpreted after death, and how frequently they are challenged.
As people live longer, they are increasingly likely to encounter cognitive conditions such as Alzheimer’s disease or other forms of dementia, particularly in later life. This means that the legal process surrounding the creation and execution of wills has become more complex, as questions of mental capacity and undue influence arise more frequently. Family members and legal representatives are now more attuned to the risks associated with diminished capacity, and probate courts are seeing a rise in claims where dementia plays a central role. The impact of this increase is twofold: there are more contested probate cases being brought forward, and the profile of these cases has changed markedly over the past decade.
Dementia, a leading cause of death
Dementia has become the leading cause of death in the UK, surpassing conditions such as cancer and heart disease. With an ageing population, one in four people in the UK is projected to be over 65 by 2050, and the number of individuals likely to be affected by some form of cognitive impairment will inevitably rise. This has implications for the legal system, where capacity is a fundamental requirement for making a valid will.
Many individuals delay making a will until later in life, often prompted by events such as retirement, the death of a partner, or a health diagnosis. This tendency to postpone estate planning coincides with the period when the risk of developing dementia increases. As a result, legal professionals frequently find themselves advising clients who may be in the early or intermediate stages of cognitive decline. While dementia does not automatically prevent someone from making a valid will, it introduces a level of uncertainty that can lead to disputes among family members and beneficiaries after the individual’s death.
Testamentary capacity and legal standards
The legal concept of testamentary capacity is rooted in the 19th-century case of Banks v Goodfellow (1870), which remains the cornerstone of English law in this area. To be deemed to have capacity, a testator must understand the nature of making a will and its effects, comprehend the extent of the property being disposed of, appreciate the claims to which they ought to give consideration, and not be affected by any disorder of the mind that influences their decision-making.
This test is different to the Mental Capacity Act 2005, which governs broader aspects of mental capacity in England and Wales. The Banks v Goodfellow test, however, remains the specific legal threshold for wills. Under both frameworks, capacity is treated as time- and decision-specific. A diagnosis of dementia, therefore, does not necessarily equate to incapacity. Many people in the early stages retain full understanding and decision-making ability. The question for probate courts is not whether a person had dementia in general terms, but whether they had the mental ability to make a will at the specific time they did so based on the specific Banks v Goodfellow test.
The presence of dementia introduces complexity into this assessment, particularly when symptoms fluctuate or progress unevenly. Solicitors must exercise careful judgment in such situations, and any lack of detailed documentation or independent verification can later expose the will to challenge. The consequence is that more wills are now being scrutinised through the lens of capacity disputes, often supported by medical evidence, solicitors’ notes, and witness statements.
Rise in contested probate cases
The number of contested probate claims has risen considerably in recent years. While official figures from HMCTS provide only a limited picture, legal practitioners report a marked increase in the volume and complexity of such cases, particularly those involving elderly testators with a history of dementia or other cognitive impairment. These disputes are not limited to high-value estates; claims are often made even where the estate is modest, especially if the distribution of assets departs from previous arrangements or expectations.
Concerns about testamentary capacity are a leading reason for challenge, often accompanied by allegations of undue influence or lack of knowledge and approval. Where a testator made substantial changes to their will shortly before death, or executed multiple wills in quick succession, these changes can prompt suspicion and scrutiny. Family dynamics also play a significant role. Disputes frequently arise when one beneficiary, often a child or carer, appears to have received preferential treatment under the latest will, prompting other relatives to question whether the testator’s decisions were made freely and with full understanding.
These developments are directly linked to the increased incidence of dementia. As more individuals experience periods of cognitive decline in later life, and as more families become aware of the legal routes available to challenge a will, probate litigation is expected to continue growing in frequency and complexity.
How disputes are evolving
In addition to becoming more common, contested probate cases involving dementia are changing in character. Increasingly, cases involve multiple wills created over a relatively short period, as testators make revisions that reflect changing personal circumstances or deteriorating health. When these wills appear to contradict long-established intentions, and especially when they benefit a different set of individuals than earlier versions, they are more likely to be challenged.
Another emerging trend is the involvement of non-family members in the testator’s final arrangements. Friends, carers, or neighbours may be named as beneficiaries, sometimes to the exclusion of family members who expected to inherit. In such cases, allegations of undue influence or coercion often follow, particularly if the new beneficiaries had a role in arranging the legal appointment or were present during the execution of the will.
Modern disputes also rely more heavily on digital evidence. Communications such as emails, text messages, and voice recordings may help establish the testator’s mental state, the presence of pressure, or the legitimacy of relationships. Courts are increasingly open to considering this type of material, and it now plays an important role alongside traditional forms of evidence such as witness testimony and medical records.
Role of expert and medical evidence
Expert opinion has become central to contested probate claims, particularly where testamentary capacity is in question. Solicitors are encouraged to follow the ‘golden rule’, seeking a medical opinion on capacity in cases involving elderly or seriously ill clients, but not all do so, and some clients decline the suggestion. In the absence of such an assessment, courts must rely on contemporaneous records, GP notes, and the recollections of legal professionals who advised the testator.
Retrospective capacity assessments, although not without controversy, are frequently used to support or challenge the validity of a will. Expert psychiatrists or geriatricians may be asked to review the medical history, assess cognitive assessments carried out during life, and provide an opinion on whether the testator is likely to have met the Banks v Goodfellow test at the relevant time.
These expert reports can be decisive in close cases. Where the evidence suggests the testator had only mild cognitive impairment, and the solicitor’s notes support the conclusion that they understood what they were doing, the court is likely to uphold the will. Conversely, where the testator was suffering from confusion, paranoia, or memory loss – and where documentation is lacking – claims are more likely to succeed.
Preventative measures for legal professionals
Given the increased risk of dispute, solicitors are advised to adopt a more cautious and comprehensive approach when working with clients who may be vulnerable. Encouraging clients to make or revise their wills early, ideally before any diagnosis of cognitive decline, is a critical first step. When a client is already living with dementia, even in its early stages, the importance of documentation becomes paramount.
Attendance notes should include detailed observations of the client’s behaviour, understanding, and reasons for decision-making. Any unusual instructions or departures from previous testamentary patterns should be explored and recorded. Where appropriate, a formal medical capacity assessment should be obtained to support the solicitor’s own judgment. In high-risk cases, it may also be beneficial to record the will-signing process on video or to use independent witnesses who have no interest in the outcome of the estate.
Clients should also be advised to put in place Lasting Powers of Attorney (LPAs) for property and financial affairs and for health and welfare. These instruments provide additional protection and allow trusted individuals to manage decisions if capacity declines. The presence of LPAs may also reduce the risk of disputes over lifetime gifts or other transactions later being challenged.
The growing prevalence of dementia in the UK has led to a demonstrable increase in the number and complexity of contested probate cases. As the population continues to age, and as more individuals experience cognitive impairment in later life, questions around testamentary capacity, undue influence, and the validity of wills will become more frequent in the courts. These developments require legal professionals to adjust their practices, particularly in relation to documentation, assessment of capacity, and the use of medical and expert evidence.
Contested probate litigation is no longer confined to wealthy estates or unusual family dynamics. It is increasingly a feature of routine will drafting involving older or vulnerable clients. Solicitors who act with foresight, care, and thoroughness can help their clients avoid posthumous litigation and uphold the integrity of their final wishes.
Alison Parry is Head of Private Wealth Disputes at JMW Solicitors
