The legalization of medical aid in dying (MAiD) in Canada and around the world, has triggered much debate. Many opponents of medical assistance in dying fear the development of a slippery slope - “if we allow MAiD for terminally ill patients, involuntary euthanasia will necessarily or very likely follow."  Even though Canada's new legislation outlines strict eligibility criteria and safeguards, many are not convinced that there can ever be sufficient protection, especially for the most vulnerable (children, the elderly, the mentally ill).

In places where euthanasia and assisted dying have been legal for many years, there seems to be no evidence of a slippery slope.

The Netherlands has reported:

"No slippery slope seems to have occurred. Physicians seem to adhere to the criteria for due care in the large majority of cases. Further, it has been shown that the majority of physicians think that the Euthanasia Act has improved their legal certainty and contributes to the carefulness of life-terminating acts." The study also showed that euthanasia without explicit consent from the patient has not increased and that “there is no evidence for a higher frequency of euthanasia among the elderly, people with low educational status, the poor, the physically disabled or chronically ill, minors, people with psychiatric illnesses including depression, or racial or ethnic minorities, compared with background populations”.

In Oregon, where the Death With Dignity Act has been in effect since 1997, government statistics show the vast majority of requests for euthanasia and assisted dying/suicide come from college educated, white males, over 55 years of age, who suffer from terminal illnesses such as cancer and ALS, and are enrolled in hospice care. 

To support their opposition to Canada's new law, many point to Belgium, the Netherlands, and Switzerland where the number of assisted deaths and euthanasia cases increase annually. 

In Belgium the rate of euthanasia increased significantly between 2007 and 2013, from 1.9 to 4.6% of deaths. The overall increase relates to increases in both the number of requests (from 3.5 to 6.0% of deaths) and the proportion of requests granted (from 56.3 to 76.8% of requests made).

Despite the high (rising) number of cases, euthanasia accounts for less than 2% of all deaths in Belgium. In the last Federal Evaluation and Control Commission report to the legislative chambers, death by euthanasia only accounted for 1.5% of all deaths from 2012-2013. Of the 3,239 cases, 87% were due to terminal illnesses (cancer tops the list at 73%). Only 4% of euthanasia cases during this period were because of a neuropsychological disorder. 

The Belgian law remained unchanged until 2014 when the right to die was extended to children. The controversial decision made headlines around the world. To date there is only one reported case of euthanasia of a minor. 

In the Netherlands minors from the age of 12 can request euthanasia. However, parental consent is mandatory if under 16 years old. 16 and 17 year olds don’t need parental consent, but parents must be involved in the process. Between 2002 and 2015 a total of five children were euthanized in the Netherlands; a12-year-old and four young people aged 16 to 17.

Even though in the Benelux countries, MAiD is available to patients suffering from mental illness and degenerative neurological disorders - terminal illness, namely cancer, remains the top motivation for choosing medical aid in dying. The Netherlands’ 2015 Euthanasia Report Card reveals that “Untreatable mental illness is a rare health factor in Dutch assisted dying, with dementia present in 1 in 50 assisted deaths (2%) and other mental illness in 1 in 100 deaths (1%)”.

Most patients cite the loss of autonomy, the inability to engage in enjoyable activities and the loss of dignity as their reason for considering MAiD. An article published in the British Medical Journal found that most requests for assisted dying "arise from a complex combination of physical, psychosocial, and existential suffering”. 

Canada is currently researching if medical assistance in dying should be extended to mature minors and people with solely mental illness.