On April 3, 2006, my father was diagnosed with Alzheimer's disease. At last, we had a name to explain, among other things, his recent confusion about what to do with the mail, his inability to write a simple shopping list, and his frequent lapses of memory. The diagnosing geriatrician showed me the CT scans. My father's brain was showing marked signs of atrophy; the gaps between the convolutions of his brain had widened, and the brain seemed to have shrunk away from the skull. My dad asked if there was anything wrong.

'Well, the good news is that there is no tumour or haemorrhage,' I said, 'but...it's an old brain.'

'It's done a lot of thinking,' added the doctor in a kindly voice.

My dad then started to tell us about some of the difficult decisions he'd been responsible for during his working life. He had been an aeronautical engineer, occasionally the one who had to decide whether an airliner full of passengers was safe to fly or not. He clearly wasn't following the real subject of our conversation.

The doctor explained, as gently as possible, that it was a disease for which there was no cure, and it would only get worse. My dad took the news calmly. For him, it was just forgetfulness, nothing serious, nothing worth seeing a doctor about.

We left the surgery after a brief discussion of the available drugs. The doctor was not pushy about medication, and my dad was clearly not interested in taking pills.

My mother, who had been quietly sitting with us during the consultation, went through the same diagnosis some three years ago. This was the second time for us, as a family. We now had two parents with Alzheimer's disease.