Misdiagnosis exposes a key flaw with assisted suicide.

Alex Schadenberg
Executive Director, Euthanasia Prevention Coalition

The UK is debating the legalization of assisted suicide. An article by Peter Sefton-Williams that was published in the Spectator on February 11, 2025 concerns him being misdiagnosed with Motor Neurone Disease (MND) in January 2024.

Sefton-Williams tells his own story. He states:

Perhaps the strongest argument against the reintroduction of capital punishment is the possibility that mistakes, once made, cannot be rectified. In the 20th century, such errors – even with legal safeguards in place – were not uncommon. Infamous cases, such as those of Timothy Evans and George Kelly, are a testament to that. It is ironic, therefore, that MPs who would strongly oppose capital punishment can, at the same time, enthusiastically support the Terminally Ill Adults (End of Life) Bill brought before parliament by Labour MP Kim Leadbeater.

The same argument applies. If a mistake is made, and a person opts for assisted dying based on incorrect information, that mistake cannot later be rectified. Supporters of the Bill talk about the rigorous safeguards that would surround the decision-making process. But, as with the legal protections surrounding capital punishment, these can fail. It’s also deeply troubling to learn this morning that one of the key safeguards in the Assisted Dying Bill – that cases have to be signed off by the High Court – may no longer apply.

Sefton-Williams tells his personal story:

For me, this is no theoretical debate. In January 2024, I was diagnosed with suspected Motor Neurone Disease (MND). Three months later, this diagnosis was confirmed. I was suffering badly from fasciculations (or twitching and cramping) in my hands and arms, and I had noticeable weakness and muscle wastage in my right hand.

The first doctor who diagnosed my condition did so after a barrage of tests and said that, although he had written “suspected” in my report, he wanted me to know that there was no doubt about the diagnosis. He explained there was no single, definitive test for MND, so he would send me to a senior specialist at a London teaching hospital for a second opinion. He also told me there was no cure and that death usually came between eighteen months and four years after diagnosis, but that the end could come much more quickly. Finally, he advised me not to make any plans beyond six months.

The senior specialist to whom I was referred examined me at the start of April and confirmed the diagnosis. He told me that, while I could live for a further five years, he had known cases where people had died within two months of diagnosis. Both doctors also warned that the degree of muscle wastage in my hand suggested I had already lived with the condition for some considerable time. 

Upon first being diagnosed, I was struck by fear and panic. I knew broadly how the end would come with MND. Muscle strength gradually fades until speech, movement, swallowing and breathing become increasingly difficult. Although I have many good friends and a supportive family, I am single and live alone. I felt I was in an impossible position and would not be able to cope with such a decline. And so, on the day after my initial diagnosis, I filled in the forms to join the Swiss assisted suicide clinic, Dignitas. I also considered other ways of terminating my life, perhaps by throwing myself off a cliff.

The Dignitas literature stressed that patients needed to administer the fatal chemicals themselves. Where patients had conditions such as MND, I determined that the procedure could not be delayed until the disease had progressed to the point of debilitation. I therefore felt under pressure to act.

Sefton-Williams received good news when he learned that he had been misdiagnosed with MND and that he actually had a treatable condiiton:

Yet as spring turned into summer, it became clear that my health was not worsening as expected. I was sent for further nerve conduction studies. These revealed that my condition was much more likely to be Multifocal Motor Neuropathy, a mild condition that is not terminal and which, in most cases, is treatable.

If assisted suicide were legal, Sefton-Williams states that would have died needlessly. 

The Bill currently before Parliament requires that two doctors independently assess and confirm that a patient has a “terminal illness” and is “reasonably expected to die within six months”. It sounds fail-safe. But in my case, I was told by two eminent specialists that I had a terminal condition and that, in the worst scenario, death could come within months. If I had had a fixed intention to terminate my life, I would surely have been a candidate. After my suicide, friends and family would perhaps have talked about my bravery in opting for a dignified death. They would have known nothing of my misdiagnosis. They would have not been aware that my death had been needless.

The question is - how many people are being killed by euthanasia or assisted suicide who have been misdiagnosed or not diagnosed?

According to Brian Mastroianni who published an article in healthline.com on February 22, 2020 medical misdiagnosis is more common than you think. According to the data: 

• In the United States, 12 million people are affected by medical diagnostic errors each year.  
• An estimated 40,000 to 80,000 people die annually from complications related to misdiagnoses and a similar number of people will experience a permanent disability related to misdiagnosis.

In February 2022, Meredith Bond reported for CityTV news that:

After 17 years suffering from chronic pain, Jennifer Monaghan began researching medical assistance in dying (MAiD), but a miracle diagnosis saved her life.

Monaghan, a Canadian, was considering euthanasia but then learned after 17-years of chronic pain that she had “Small fiber sensory neuropathy,” which is a treatable condition. Monaghan is alive today because she was fortunate to have been diagnosed with a treatable condition.