A study of healthy teenage girls at high risk of developing depression due to family history of the disorder has found that if the girls were stressed, they responded by releasing much higher levels of the hormone cortisol.
The study also showed that they had shorter telomeres, which are the buffer at the end of chromosomes. While telomeres shorten over time, the girls had telomeres that were shorter by the equivalent of six years in adults.
This has prompted the psychologist conducting the study, Professor Ian Gotlib, to ask what comes first: stress, depression or premature ageing?
Before the study no-one had examined telomere length in young children who are at risk for developing depression.
"I did not think that these girls would have shorter telomeres than their low-risk counterparts – they're too young,” Professor Gotlib said.
"It's the equivalent in adults of six years of biological ageing," Gotlib said.
So what can a concerned parent do?
Professor Gotlib noted that other research shows that exercise is one of the most effective strategies in delaying telomere shortening in adults.
“As a matter of course, I recommend that all young people including teenage girls exercise regularly. For girls who are in this high-risk category, I recommend that parents also help them to learn stress reduction techniques.”