A recent High Court case, Ginger v Mickleburgh, is a powerful example of how things can go wrong when mental health issues and family tensions intersect leading to an invalid Will.

Background information

The case centred on Michael Gwilliam (Michael) who died in February 2022 with a Will dated 3 December 2014. Instead of leaving most of his estate to his daughters, who he had previously been close to, he gave them only a small share. The bulk went to other relatives including his sister, his ex-partner, 25% to his three nephews and only 25% of his estate to his four daughters.

So why the change?

The court heard evidence that, in his later years, Michael developed serious mental health problems. Michael came to believe things about his daughters that simply weren’t true, such as that they were stealing from him or trying to have him forcibly detained. These weren’t just passing suspicions; they were fixed, deeply held beliefs.

After his death, his daughters challenged the will.

What did the court decide?

The judge ultimately ruled that the will was not valid.

The key reason was that Michael lacked what the law calls “testamentary capacity”, in other words, he wasn’t in a sound enough state of mind when he made the will. While he may have understood that he was making a will and what property he owned, his decisions were influenced by false beliefs about his daughters.

Because those beliefs directly shaped how he divided his estate, the will couldn’t stand.

As a result, his estate was treated as if he had no valid will at all, and it will instead be distributed under the standard intestacy rules.

What about wrongdoing by others?

The daughters also argued that other family members had turned their father against them by feeding him false information.

This is known in law as “fraudulent calumny”, essentially poisoning someone’s mind with lies.

However, the court did not agree with this argument and did not find in favour of this. While others may have repeated or reinforced the negative beliefs, there wasn’t enough evidence that they had deliberately lied or acted dishonestly. In law, that distinction matters a lot.

Key takeaways (why this case matters)

1. Mental health can affect a will, even if it looks valid on the surface
Someone can appear capable in many ways, but if a specific false belief drives their decisions about who should inherit, that can invalidate the will.

2. It’s not enough to show someone was unwell, you must show it affected the will
The court focused on a crucial question: Did the illness actually influence the outcome? In this case, the answer was yes.

3. Proving dishonesty is difficult
Even if family members contributed to a misunderstanding, that doesn’t automatically mean legal wrongdoing. Fraud requires clear evidence of intent to deceive.

4. Professional involvement isn’t a guarantee
The will in this case was professionally prepared, but that didn’t save it. The judgment highlights the importance of taking extra care where someone’s mental capacity might be in doubt.

Final thought

At its heart, this case is a reminder that wills are about more than legal formalities, they’re about human relationships and state of mind of the testator. When those are compromised, even a formally, professionally prepared will may be found to be invalid.

For families, it’s a prompt to address concerns early should you have concerns about the validity of a will due to the mental health of the testator. And for professionals, it’s a warning to look closely when something doesn’t quite add up.

If you’re dealing with concerns about a will and a loved one’s capacity at the time of making that will, get in contact with our Contentious Probate and Trusts team who can assist you.