With age, however, adults lose the ability to produce this second hormone and so they become more vulnerable to disease at moments of stress, say the researchers.
Lord said: "We think that what is going on is that even in previously healthy people are becoming very depressed and this has a powerful effect on the immune system. A 70-year-old has around 10 to 20 per cent of the DHEA of a 30-year-old, so it may be why older people are less able to cope with bereavement."
