“One of the first problems of Alzheimer’s is actually a sense of depression, because they know where this is going and they get incredibly depressed about it. And of course, it has such an unhappy ending.”He recalled his sister, Clare, being asked on several occasions by their mother to “kill her”.Lord Cameron told the Telegraph: “‘Will you kill me? You know how to do it, Clare. Will you kill me?’ she would ask. “She said, ‘Mum, even if I did know how to kill you, I don’t want to go to prison for murdering my mother’.”