Stress may impair memory and thinking skills

Researchers gave tests for memory, abstract reasoning, visual perception and attention to 2,231 people, average age 49 and free of dementia. They recorded blood levels of cortisol and did MRI examinations to assess brain volume.

The study, in Neurology, controlled for age, sex, education, body mass index, blood pressure and many other variables, and found that compared with people with average levels of cortisol, those with the highest levels had lower scores on the cognitive tests. In women, but not in men, higher cortisol was also associated with reduced brain volume. There was no association of the lowest cortisol levels with either cognitive test scores or brain size.

The lead author, Dr Justin B Echouffo-Tcheugui, an assistant professor of medicine at Johns Hopkins, said that the study suggests that even in people without symptoms, higher cortisol levels can be significant.

Still, he said, “This is an initial study. The next step is a prospective study before we jump to the conclusion that this is really important. It’s premature now to consider intervention.”