Nov. 16, 2005 -- A common migraine drug can restore mental flexibility lost to stress, researchers report.
Stress makes you alert. It makes you attentive. These are good things, if flight or fight are your best responses to stressful situations -- as they were during millions of years of evolution.
Fighting and running away aren't likely to be good responses to the stresses that afflict modern humans. We need mental flexibility in order to solve problems. Unfortunately, stress takes away much of our mental flexibility, finds Ohio State University neurologist David Beversdorf, MD, and colleagues.
But Beversdorf's team also finds that taking a common drug -- a beta-blocker sold as Inderal and in generic forms -- restores problem-solving ability to people under stress.
"Real-world types of stressors can significantly impair the ability to think flexibly," Beversdorf says in a news release. "The [beta-blocker] actually reversed the stress-induced [mental] problems and improved performance levels to within the range participants reached when they weren't under any stress."
Beversdorf reported the findings at this week's annual meeting of the Society for Neuroscience in Washington.
Shrek vs. Private Ryan
Beversdorf and colleagues first looked at the effects of stress on mental function. To do this, they asked six men and six women to watch two different film clips. One of the clips was the first 20 minutes of the animated comedy Shrek. The other was the first 20 minutes of the film Saving Private Ryan, a graphic and emotional depiction of D-Day, the invasion of Normandy during World War II.
After watching each film clip, study participants had to take tests in which they received a list of three words and had to come up with a new word that made each item on the list into a compound word. They also did a memory test in which they had to recall a series of random numbers of increasing length.
Subjects got about 40% fewer correct answers on the word-problem test after watching the stressful movie than they did after watching the comedy. But they didn't do any worse on the memory test.
This led Beversdorf and colleagues to the conclusion that stress affects specific mental functions by activating a specific part of the brain. Beta-blockers slow this activity. Might they help restore problem-solving ability under stress?
Public Speaking and Beta-Blockers
This time the researchers stressed out 16 adults by asking them to make a speech before a panel of unsmiling panelists wearing white lab coats. They were interrupted every minute or two and asked to perform mental arithmetic. They then underwent tests that included unscrambling anagrams and word association.
The study participants also took these same kinds of tests after undergoing the stress-free experience of reading aloud and counting while sitting in a room.
Test scores were much worse after the stressful situation than after the stress-free situation. But when study participants took 40 milligrams of Inderal before the stressful situation, their test scores were just as good as when they were not under stress.
"What we found is that the stress of public speaking triggers the brain's normal response to stress, and that stress response is enough to impair [mental] flexibility," Beversdorf says. "In turn, 40 milligrams of [Inderal] is enough medication to reverse this effect in healthy people."