Certain cases of major depression are associated with premature aging of immune cells, which may make people more susceptible to other serious illness, according to findings from a new UCSF-led study.
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 study was published online in March 2011 by the journal PLoS One and is available here.
"There's a lot more to depression than feeling blue," said first author Owen Wolkowitz, MD, a professor of psychiatry at UCSF. "As if feeling depressed is not bad enough, we are finding that long-term depression may be associated with damage to cells in the body, and this may predispose patients to certain physical diseases."
Previously considered a mental illness affecting only the brain, major depressive disorder, or MDD, now is believed to be tied to significant physical damage outside the brain, explained Wolkowitz. For example, depressed individuals are more likely to develop the diseases of advanced age, including diabetes, heart disease, osteoporosis, stroke and dementia.
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.
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. Telomere shortening predicts earlier onset of several major age-related diseases and earlier mortality, and may serve as one index of human longevity.
The researchers compared the length of telomeres in 18 individuals with MDD not currently receiving antidepressant medications to the length of telomeres in 17 healthy controls. Overall, telomeres of the depressed group did not differ from those o
|Contact: Kate Vidinsky|
University of California - San Francisco