“The legalization of euthanasia and assisted suicide could be the beginning of a “slippery slope” that facilitates euthanasia practices, not only in terminal patients.”

In countries where euthanasia and assisted suicide have been legalized certain — usually stringent —, conditions are required so that these practices can be carried out. Over time, however, these initial requirements may be eased, until they are accepted under virtually any circumstances. This could happen with euthanasia, which may even reach the point where it can be practiced without an express request by the patient, i.e., it could become involuntary euthanasia. This is what has come to be called the “slippery slope.”

In our view, the main bioethical, medical and social problems that may arise as a result of the slippery slope after the legalization of euthanasia are: a) that euthanasia techniques may be applied to non-terminally ill patients, thus opening up their use to anyone who wishes to end their life; b) that these practices may also be used in intellectually disabled persons or those with mental disorders; c) that these practices may also be carried out in adolescents, children and newborns;  d) that any person can request them, simply because they are tired of living; and e) more seriously, if that is possible, that they may extend to the practice of involuntary euthanasia.

Euthanasia in non-terminally ill patients

The first door that could be opened as a consequence of the slippery slope is that euthanasia could be used by anyone, even if they are not in the terminal phase of a disease. In other words, euthanasia could be legalized simply on request.

Euthanasia in persons with psychiatric disorders or mental disabilities

The second is that euthanasia could be used in psychiatric, mentally impaired or intellectually disabled patients, none of them terminally ill. This may be even more serious ethically, given that these patients do not usually have the intellectual capacity or sufficient discernment to request euthanasia with full knowledge of what they are asking for.

However, euthanasia requests for psychiatric reasons for terminally ill patients are rare, accounting for only 3% of all euthanasia requests in the Netherlands, only 2% of which are met; however, this percentage increases to 24% in non-terminal patients.

Breaking it down into specific figures, in the Netherlands, between 2002 and 2013, 179 cases of euthanasia were recorded in psychiatric or dementia patients, constituting 0.5% of all euthanasia requests. More recent data show that, in 2018, there were 6,126 cases of euthanasia, corresponding to 4.4% of all deaths; of these, 67 were in psychiatric patients.

The legalization of euthanasia has also been requested for non-terminally ill Alzheimer’s patients, which is the subject of much ethical debate in the specialist literature. In this respect, possibly the first patient with Alzheimer’s disease for whom euthanasia was sought was the Belgian writer Hugo Claus, who, knowing incipient Alzheimer’s, requested and was granted euthanasia in 2008.

Euthanasia practiced without an express request by the patient

An added problem when assessing the ethicality of euthanasia requests for non-terminal psychiatric patients or those with dementia or Alzheimer’s disease is that many of them are not competent to independently make responsible decisions. This role must therefore be assumed by a close relative or even by their attending medical team, which adds a further ethical difficulty to this practice, as the request for euthanasia may respond more to the interests of the family or the medical team than the good of the patient.

Apart from the above, however, in the opinion of palliative care specialists, when euthanasia is requested by psychiatric patients, it should be borne in mind that this request is more often a cry for help than an express demand for euthanasia. Such requests, therefore, require very rigorous medical and ethical evaluation.

Euthanasia in newborns, children and adolescents

Another serious consequence that may be derived from the slippery slope, and that could develop after the legalization of euthanasia, is that it may encourage, or even promote, euthanasia in adolescents, children and newborns, which can certainly be considered ethically very negative.

Euthanasia was legalized for adults in the Netherlands in 2002, but was also tacitly admitted for newborns and children. This acceptance grew further in March 2005, when the so-called “Groningen Protocol” was adopted, promoted by a team of physicians from the University Medical Centre Groningen. The publication of this protocol sparked major social, medical and ethical controversy, assuming that it could lead down a slippery slope towards more widespread practice of euthanasia in newborns and children.

Euthanasia for adults was also legalized in Belgium in 2002, although euthanasia for children was not included at that time. However, in February 2014, the Belgian parliament legalized euthanasia for children of any age.

As expected, as in the Netherlands, the adoption of this law triggered an extensive social and medical debate, given its radical nature, with some experts calling it the most radical in the world. For this reason, a group of 160 Belgian pediatricians strongly opposed it, questioning whether children had sufficient capacity of intellectual discernment to be able to make their own decisions with responsible autonomy. In addition to these medical professionals, representatives of the main religions and philosophical groups also protested against the adoption of this law.

In general, the main ethical difficulty that euthanasia in minors may pose is that children are not moral agents with sufficient capacity to be able to make their own decisions in the event of an incurable terminal disease. Accordingly, some experts think that the Groningen Protocol is leading to involuntary euthanasia in minors.

Euthanasia for non-sick people who say they are tired of living

This possibility shows one of the most sinister faces of euthanasia, where the arbitrariness of its application bears no relation to the existence of unbearable physical suffering or incurable diseases, but opens the possibility to extend it as a purported solution to the lack of vital sense. This implies a renunciation of all hope for those who seek the meaning of their life, and a clear symptom of the moral decay of a society that approves these practices.

Involuntary euthanasia

As previously mentioned, one of the most serious consequences of the legalization of euthanasia is that it may open the door to involuntary euthanasia, because there is currently sufficient evidence that this is the case, based on what has occurred in the two countries where euthanasia and assisted suicide have been legalized, the Netherlands and Belgium.

In fact, a paper published in 2005 that analyzed what happened in the Netherlands after the legalization of euthanasia found that of all the deaths that occurred in the country, 1.7% were due to acts of euthanasia; 0.4% of these were carried out without the patient’s express request, i.e. they were involuntary euthanasia. This percentage increased in 2001 to 0.7%.

In 2009, seven years after euthanasia was legalized in the Netherlands, another article was published, which included data from 1690 patients who had been euthanized. It found that euthanasia was applied in 1.4% of patients without their express request. In other words, they had undergone involuntary euthanasia.

A year later, a well-documented article on end-of-life practices in terminally-ill Dutch patients was published in The Lancet, addressing among many other things, the issue of involuntary euthanasia. It found that deaths from euthanasia or assisted suicide without the patient’s express request, i.e. involuntary euthanasia, ranged from 0.2% to 0.8% of all euthanasia acts in the Netherlands.

Finally, in Belgium, according to a paper published in the Journal of Medical Ethics in 2015, in patients aged 80 years or older, the percentage of involuntary euthanasia rose to 52.7%, but in patients with diseases other than cancer, this percentage reached 67.5%.


In summary, the legalization of euthanasia and assisted suicide could be the beginning of a “slippery slope” that facilitates euthanasia practices, not only in terminal patients experiencing unbearable suffering, but also in non-terminally ill patients or even in people without any verifiable suffering. Above all, however, the most serious issue, in our view, is that it paves the way to “involuntary euthanasia”.

Justo Aznar

Bioethics Observatory – Institute of Life Sciences

Catholic University of Valencia


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