As humanity ages the numbers of people with dementia will surge

A FEW DAYS shy of her 90th birthday, tortured by leg ulcers and arthritis, Vera, one of some 850,000 Britons with dementia, has kept herself alive, it seems, to meet her first grandchild, due any moment now. But when the happy day comes and the baby is brought to her, she is confused. She recognises her daughter-in-law, but is puzzled by the bundle in her arms. “That’s nice, dear,” she says. “But why have you brought me a coconut?”

Dementia is a cruel condition, robbing people of their deepest joys and hopes. It may start as a “mild cognitive impairment” (MCI): forgetfulness or “senior moments”. But as it progresses, attacking mental agility and eating away memory, it steals much of what counts as identity. When severe, people become incapable of looking after themselves. They lose the ability to read, cook and shop. They forget to drink and get dehydrated, or become incontinent. They suffer delusions, or become frightened or angry, or they sink into an apathetic slump. They require care for all their waking hours, and often supervision when asleep.

The covid-19 pandemic has been a huge ordeal for people with dementia. The loss of routine and social contacts under lockdown have hastened cognitive decline. Dementia patients have proved highly susceptible to the virus—in Britain some studies suggest it has been the...