As for Belgium, maybe not:
Two deaf twin brothers in Belgium were euthanized by their doctor after realizing they were going blind and would be unable to see each other ever again... The brothers are unique in that their illness was not terminal. Belgian law, however, allows doctors to euthanize "suffering" patients who are both mentally sound, over 18 and want to die.
Belgian lawmakers are considering a law that would extend euthanasia to dementia patients and children, whose families and doctors consented.