Unprecedented levels of stress can cause disruptions in the thinking proceses of men, an American research team has found. The theory is based on the results of brain scans of 20 male medical students preparing for their board exams.


Bruce S. McEwen, head of the Harold and Margaret Milliken Hatch Laboratory of Neuroendocrinology at The Rockefeller University, revealed that the stressed students had a harder time shifting their attention from one task to another than other healthy young men who were not under the gun.

The researcher, who worked on the project with colleagues at Weill Cornell Medical College, says that the current study builds on a previous one that showed that stressed rats foraging for food had similar impairments, and that those problems resulted from stress-induced changes in their brain anatomy.

Writing about their work in the Proceedings of the National Academy of Sciences, the researchers revealed that they used functional magnetic resonance imaging (fMRI) to scan the stressed students' brains.

They said that their study was a robust example of how basic research in an animal model could lead to high-tech investigations of the human brain.

"It's a great translational story. The research in the rats led to the imaging work on people, and the results matched up remarkably well," says McEwen.

The study also revealed that the stressed brain recuperates quickly. It showed that less than a month after the stress goes away, the brains were back to normal.