The research shows that there may be a link between stress and dementia

The research shows that there may be a link between stress and dementia

Bereavement, divorce and work problems can all trigger "severe and long-standing physiological and psychological consequences", in line with the Swedish research.

It investigated the psychological impact of 18 stress factors on 800 women from 1968 to 2005.

A quarter of volunteers had suffered one or more stressful event - 16 per-cent have been through four or maybe more.

Nearly one in five got dementia - almost exactly the number who faced increased risk factors, in accordance with the Gothenburg University findings in online journal BMJ Open.

Dr Doug Brown, of the Alzheimer's Society, said: "We all undergo stressful events. Understanding how you can turn into a risk factor for Alzheimer's is vital to helping us find means of preventing or treating it."