Otherwise healthy girls at high-risk for depression may be aging at a faster rate than their peers .
A new study shows the girls with a family history of depression respond to stress by releasing much higher levels of the hormone cortisol .
They also have telomeres that are shorter by the equivalent of six years in adults. Telomeres are caps on the ends of chromosomes. Every time a cell divides the telomeres get a little shorter .
Telomere length is like a biological clock corresponding to age . Telomeres also shorten as a result of exposure to stress .
Previous studies have uncovered links in adults between shorter telomeres and premature death, more frequent infections , and chronic diseases .
“I did not think that these girls would have shorter telomeres than their low-risk counterparts—they’re too young ,” says Ian Gotlib, professor of psychology at Stanford University .
SIX YEARS OLDER
For the study , published in Molecular Psychiatry , researchers recruited 10- to 14-year-old healthy girls with a family history of depression and compared them to healthy girls without that background .
Researchers measured the girls’ response to stress tests , asking them to count backward from 100 by 7 , and interviewing them about stressful situations. Before and after the test, the team measured the girls’ cortisol levels and also analyzed DNA samples for telomere length .
“ No one had examined telomere length in young children who are at risk for developing depression ,” before the study , Gotlib says .
Healthy but high-risk 12-year-old girls had significantly shorter telomeres, a sign of premature aging .
“It’s the equivalent in adults of six years of biological aging,” Gotlib says, but “it’s not at all clear that that makes them 18 , because no one has done this measurement in children .”
WHAT TO DO?
Exercise has been shown to delay telomere shortening in adults , so girls at high-risk girls should learn stress reduction techniques , Gotlib says .
Other studies show that neurofeedback and attention bias training (redirecting attention toward the positive) seem promising . Other investigators are studying techniques based on mindfulness training .
Gotlib says he and colleagues are continuing to monitor the girls from the original study . “ It’s looking like telomere length is predicting who’s going to become depressed and who’s not .”
The National Institute of Mental Health supported the study .
Original Article ：
《Telomere length and cortisol reactivity in children of depressed mothers》, Published on Journal《Molecular Psychiatry》on 25th September , 2014 .