mother, and that mortier's complaint to the european court has no legal standing. but there have been other controversial cases that have raised eyebrows, including: a transgender patient who was euthanized because of depression following an unsuccessful sex change operation; and twins who were chronically ill, deaf and going blind who were euthanized together. >> those cases are really extremely rare, so we can mention them, it's okay to discuss them, but we should not bring them to the front to say... to put the law into question because the law is not primarily made for these cases. >> reporter: in fact, dr. marc van hoey says only about 5% of his cases were psychiatric patients. but he doesn't shy away from discussing them. as he sees it, euthanasia can be a less traumatic option for a patient and their family than some other form of suicide. can it be emotional for you? are some cases harder than others? >> it's always emotional. and what i always say to my colleagues, nurses, and also to the family i say this, try to bear in mind you follow the law and it's t