[Dr Ritchie’s] claims are based on studies of French citizens forcibly expelled from Algeria in the 1950s.
Known as the ‘pieds noirs’, they had crossed the Mediterranean and many had settled in the coastal district around Montpelier, where the research was conducted.
She said: ‘They had suffered extreme stress, losing their homes, and having their lives threatened, sometimes by people who were once their neighbours.
‘The ones who had the worst symptoms (of dementia) now were those who had suffered most at the time.
‘These people needed help when they were ten or 20, not when they were 65.’