In Belgium and the Netherlands, where euthanasia and physician-assisted suicide are legal, doctors are increasingly confronted by requests for such services from people with psychological illnesses or people who say they are "tired of living," a new study finds.
The majority of these requests are denied, according to two studies focused on such clinics.
Still, some patients did get their wish granted and received help ending their life. The studies were published Aug. 10 in JAMA Internal Medicine.
The findings highlight worries about a "slippery slope" in terms of the reasons for which euthanasia requests might be granted, two U.S. experts said.
"Although neither article mentions the term 'slippery slope,' both studies report worrisome findings that seem to validate concerns about where these practices might lead," Drs. Barron Lerner and Arthur Caplan of New York University's Langone Medical Center, wrote in a journal commentary.
In the first study, Dutch researchers led by Marianne Snijdewind of VU University Medical Center in Amsterdam, looked at requests for euthanasia or doctor-assisted suicide received by one clinic.
The clinic was founded in 2012 specifically to help patients who met all the legal requirements for euthanasia/doctor-assisted suicide, but whose own doctors had refused their requests.
Even so, a majority of requests made to the clinic in 2012-2013 weren't granted. In their survey of 645 requests, Snijdewind's team found that only a quarter were granted. Nearly half (46.5 percent) were refused.
About a fifth of patients died before the request could be assessed. Around 9 percent of patients ended up withdrawing their requests, the Dutch team noted.
The condition the patient suffered from seemed to matter in terms of whether a request for euthanasia was granted.
About one-third of people with physical ailments -- conditions such as cancer, heart disease, neurological or other advanced illnesses -- had their request granted, compared to just 5 percent of people with a psychiatric or psychological condition, the researchers said.
But close to one-third (27.5 percent) of 40 requests were granted for people who were described as being "tired of living," the Dutch team said.
But, overall, "the physicians and nurses employed by the clinic . . . often confirmed the assessment of the physician who previously cared for the patient," the study authors said.
In a second study, a team led by Sigrid Dierickx, of Vrije University Brussels, surveyed Belgian doctors connected to almost 6,900 cases involving a patient's death.
Belgium legalized euthanasia in 2002, and the new study compared the results of the new survey (conducted in 2013) to one conducted in 2007.
The survey found a rise in the percentage of patients who made a request for euthanasia from 3.4 percent of cases in 2007 to 5.9 percent in 2013, the researchers said.
And while just more than half of those requests (55 percent) were granted in 2007, by 2013 that number had risen to more than three-quarters (about 77 percent).
Key reasons for saying "yes" to a request for euthanasia were physical and/or mental suffering, and doubt that the patient's condition would ever improve, the study found.
Patients with cancer were among those most likely to request euthanasia, and patients with college degrees were more likely to make such requests versus less-educated people, the investigators found.
In their commentary, Lerner and Caplan say that "although the euthanasia practices in the Netherlands and Belgium are unlikely to gain a foothold in the United States, a rapidly aging population demanding this type of service should give us pause."
The "slippery slope" -- where the reasons requests for euthanasia are granted become more numerous -- is a worry, the NYU experts say.
"There are numerous groups that are potentially vulnerable to abuses waiting at the end of the slippery slope -- the elderly, the disabled, the poor, minorities and people with psychiatric impairments," they wrote.
"When a society does poorly in the alleviation of suffering, it should be careful not to slide into trouble. Instead, it should fix its real problems."