Researchers found people with PTSD were more likely to have shorter telomere length - an indicator of premature aging.
Around 7-8% of the US population will experience post-traumatic stress disorder (PTSD) at some point in their lives.
The condition can occur after exposure to a traumatic event. A person with PTSD may experience nightmares, have flashbacks of the event, avoid places or situations that remind them of the event and suffer hyperarousal symptoms - such as nervousness and tension.
This latest study, conducted by researchers from the University of California-San Diego School of Medicine and the Veterans Affairs San Diego Health System, is the first of its kind to associate PTSD with a biological process like premature aging.
To reach their findings, the team conducted a comprehensive review of studies connected to early aging among individuals with PTSD dating back to 2000.
Since there is no standard definition for premature or accelerated aging, the researchers say, they looked at nonpsychiatric disorders that incorporate early aging, such as progeria syndrome and Down's syndrome, as a guide.
The team identified 64 studies that they deemed appropriate for investigation into the link between PTSD and aging. They were able to use these studies to assess how PTSD affects biomarkers of accelerated aging - such as telomere length - and how it affects onset and prevalence of age-related medical conditions and overall mortality.
PTSD linked to shorter telomere length, earlier mortality
The researchers found that, compared with individuals without PTSD, people with the condition had reduced telomere length.
Telomeres are caps on the end of each DNA strand that protect the chromosomes. Telomere length reduces with each cell replication and this is considered to be a marker of aging.
The team also found that people with PTSD were more likely to have increased levels of pro-inflammatory markers, such as C-reactive protein (CRP) and tumor necrosis factor alpha (TNFα), which are said to be markers of aging.
What is more, some of the studies reviewed suggested a mild-to-moderate link between PTSD and earlier mortality, which the team says is consistent with premature or accelerated aging among people with the condition.
Though the researchers say their study does not show whether PTSD is a specific cause of premature aging, they believe it highlights the need to class PTSD as more than just a mental illness.
First study author Dr. James B. Lohr, professor of psychiatry at UC-San Diego, adds:
"Early senescence, increased medical morbidity and premature mortality in PTSD have implications in health care beyond simply treating PTSD symptoms. Our findings warrant a deeper look at this phenomenon and a more integrated medical-psychiatric approach to their care."
The team stresses that further studies are needed to confirm their findings and determine the mechanisms behind the association between PTSD and premature aging.
In January, Medical News Today reported on a study by researchers from the University of California-Los Angeles that identified two gene variants that may increase the risk of PTSD.