A new study suggested cells in people suffering from depression may age faster than in other individuals.
Dutch researchers looked at telomeres in about 2,400 people. Telomeres can be compared to the plastic tips on shoelaces, except in this case the "shoelace" is a chromosome; their purpose is to protect DNA from damage, HealthDay reported.
These telomeres wear down every time the cells divide, which can help researchers tell the age of the organisms.
In the study, the researchers found that the telomeres in people that had ever suffered depression were significantly shorter than others'. Even after the research team factored in other lifestyle variables that could affect telomere length, the results remained the same.
The study subjects that had been depressed had telomeres that were, on average, "83 to 84 base pairs of DNA shorter" than those that had never struggled with depression. People normally lose 18 to 20 base pairs per year, meaning those who had suffered depression had cells that were between four and six years older than those who had not.
Researchers are not sure if the results mean an actual cause-and-effect link. It could be that shorter telomeres contribute to depression; but it is more likely that depression causes damage to the cells which results in shorter telomeres.
"Results like ours suggest that psychological distress, as experienced by depressed persons, has a large, detrimental impact on the wear and tear of a person's body, resulting in accelerated biological aging," study author Josine Verhoeven, a doctoral researcher at VU University Medical Center in Amsterdam, said, HealthDay reported.
Some researchers believe the study is strong because of the number of participants.
"The strength of this report is its size," Etienne Sibellie, an associate professor of psychiatry at the University of Pittsburgh, who was not involved in the study, said.
It's just not known whether it has an impact on cell function," he said. "If that's the case, it has potential therapeutic importance."
