This is legalised and regulated in the US States of Oregon and Washington. The proof of a working system is in Oregon USA where for over 18 years it has been successful, with no cases of abuse and no calls to extend the law beyond terminally ill, mentally competent adults. which is a very similar situation to what lord falconer wanted to put in place with his bill. where "On October 27, 1997 Oregon enacted the Death with Dignity Act which allows terminally-ill Oregonians to end their lives through the voluntary self-administration of lethal medications, expressly prescribed by a physician for that purpose."
In recent cases such as in Belgium, where even children may be euthanized, are going far and beyond what it should be there for. in the case of Godelieve De Troyer, who suffered from server depression but was physically healthy and not suffering from physical pain, was euthanised. But even though she was taking medication which can cause suicidal ideation, Dr Distelmans sill performed the euthanasia. The main arguments of this which sit on one of the foundations of the argument of not allowing a reform was, that doctors treatment for patients will deteriorate and go against their ethical