New research shows that people who are depressed are susceptible to premature aging of immune cells, which could in turn open the door to serious illness, such as diabetes, heart disease, osteoporosis, stroke and dementia.
The findings indicate that accelerated cell aging does not occur in all depressed individuals, but is dependent upon how long someone is depressed, particularly if that depression goes untreated, the University of California at San Francisco (UCSF) researchers noted.
Previously considered a mental illness affecting only the brain, major depressive disorder now is believed to be tied to significant physical damage outside the brain, explained first author Owen Wolkowitz, M.D., in a UCSF press release.
In probing the links between depression and physical disease, the research team explored aging of the immune system as measured by the shortening of telomeres in immune cells taken from the blood, according to the press release.
Telomeres are tiny units of DNA-protein complexes that seal off and protect the ends of chromosomes and act as a biological clock controlling a cell’s life, the press release noted. Telomere shortening predicts earlier onset of several major age-related diseases and earlier mortality, and may serve as one index of human longevity.
“While this finding itself might seem depressing, there is yet good news: many lifestyle factors like exercise and aspects of diet have been linked to longer telomeres,” said co-author Elissa Epel, Ph.D., an associate professor in the UCSF Department of psychiatry. “So while our personal history matters, it is possible that what we do today may matter even more, in terms of protecting our telomeres.”
The study was published online in March 2011 by the journal PLoS One.