Stress Hormone May Drive Risk Taking by Teen Motorists

Teens whose brain chemistry is less affected by stressful situations could be at increased risk for car crashes, a small Canadian study suggests.

Safe-driving teens appear to have higher levels of the stress hormone cortisol, said study author Marie Claude Ouimet, an associate professor of medicine and health sciences at the University of Sherbrooke, in Quebec.

The brain calls for the release of cortisol as part of its “fight-or-flight” response to stressful or dangerous situations. In the study, teens more likely to crash or come close to crashing a car tended to have less cortisol in their system — indicating that their response to a risky situation may be blunted in some way, researchers say.

“It tells us that maybe some people are more neurobiologically predisposed to risk-taking, or maybe less able to change their driving as a result of experience,” said Ouimet.

Ouimet and her colleagues tracked 42 volunteers in the United States, all aged 16, for the first 18 months after they received their driver’s license.

At the start of the study, the researchers measured each teen’s stress response by asking them to solve a series of math problems, telling them that $60 would be awarded to the person with the highest score.

Doctors took saliva samples from teens to measure their cortisol levels before and after the math problems, and used those samples to estimate each kid’s response to stress.

The teens were then let loose on the roads, in cars that measured their driving behavior using a series of sensors, cameras and GPS.

Researchers found that the teens with a higher cortisol response to stress were less likely to crash or experience a near crash, according to the results published online April 7 in the journal JAMA Pediatrics.

Teens with a greater stress response also experienced a faster decline in their crash/near crash rate over time, indicating that their driving safety improved more quickly than that of teens with a low cortisol response to stress.

Source: U.S. News & World Report
http://health.usnews.com/health-news/articles/2014/04/07/stress-hormone-may-drive-risk-taking-by-teen-motorists