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.
Source: Stanford University