LOS ANGELES: Saliva tests may help to identify people at risk of thinking and memory problems, research suggests.
Scientists found that high saliva levels of the stress hormone cortisol in the evening correlated with smaller brain volume and poorer performance in mental ability tests.
The lead researcher said: “Studies have shown that depression increases the risk for dementia, but we don’t know much about how this relationship occurs.
“High levels of the stress hormone cortisol have been found in people with depression, and the theory is that cortisol has a toxic effect on the hippocampus area of the brain, which plays an important role in memory.”..