News that trials of a drug intended to halt the progress of Alzheimer’s disease have stopped will come as a bitter disappointment to the many around the world affected by what must be one of the worst of all illnesses. To watch someone you knew and loved slowly disappearing is a bereavement that can last for years. There seems no predicting who will develop the illness, nor knowing how it will progress. Sometimes, it seems to stay away, and then arrive unexpectedly, as happened to a family member.

At 77 she met us at Vancouver airport in a Ford Taurus, a car that made our Ford Mondeo at home in Ireland look like its little sister. She spent three days driving us around the city, including having no hesitation in driving downtown, before taking us on a car ferry to visit Vancouver Island, where we stayed on the waterfront in Victoria. She was an avid listener to CBC, a determined supporter of public service broadcasting, a theatre and concert goer. Sprightly, fit; an active and inquisitive mind, and an encyclopaedic memory, she was the model of what life as a senior should be like.

At 87, she had decided the long car journeys should be a thing of the past, but had no problem in the city.  She made up spare beds for our visit; made breakfast in the mornings and joined us in restaurants for meals in the evening.  Her interest in politics and current affairs was as keen as ever; her recall of every detail of the family tree was impeccable. She laughed and joked with our teenaged children. It seemed inconceivable that she would not see out her days as young and lively as she had always been.

Last year, she was 90 and there was evident pain in her face as she admitted she did not recall events. She was annoyed at being told of something a month earlier. She rationalized a failure to recall an important moment: her ninetieth birthday when she had cut her hand and had been forced to go to the Emergency Room at the city hospital. There was no purpose to be served in talking of forgotten things; it was much happier for all of us to stay in the realm of the remembered than to attempt conversations that might cause distress.

This year, even attempting to telephone is likely to cause confusion.

Perhaps most of us will not reach the age of 90, but we are all living longer and the longer we live the greater the chance that sooner or later we will develop dementia. The failure of the trials is bad news not only for the sufferers and their families and carers, it is bad news for all of us who are going to be part of an ageing population.