Adults who suffer from post-traumatic stress disorder (PTSD), and also have a childhood history of trauma, are at greater risk for age-related diseases, including cancer, cardiovascular disease, autoimmune and neurodegenerative diseases, as well as early death, due to a significantly shorter length in telomeres.
Telomeres are DNA-protein complexes that close and protect the ends of chromosomes.
Researchers at the San Francisco VA Medical Center and the University of California, San Francisco took DNA samples from 43 adults with PTSD as well as 47 controls without PTSD. Initial results showed that overall, the participants with PTSD had shorter telomere length than those without the disorder.
“This was striking to us, because the subjects were relatively young, with an average age of 30, and in good physical health,” said lead author Aoife O’Donovan, a researcher in psychiatry at SFVAMC and UCSF. “Telomere length was significantly shorter than we might expect in such a group.”
Next, researchers looked into whether volunteers had any history of severe childhood trauma, including neglect, family violence, physical abuse, and sexual abuse. The results showed that , among the subjects with PTSD, the greater the childhood trauma a person had suffered, the shorter the telomere length.
“People who had multiple categories of childhood traumas had the shortest telomere length,” said O’Donovan.
Interestingly, participants with PTSD but no history of childhood abuse had telomere length equal to those of the healthy control group.
The results are intriguing for a number of reasons, observed principal investigator Thomas Neylan, M.D., director of the PTSD program at SFVAMC and a professor in residence of psychiatry at UCSF.
“For one thing, this gives us a potential mechanism for why people with PTSD tend to have a greater disease burden and more problems with aging,” said Neylan. “It might be because of their telomere biology.”
“We might be seeing the cumulative effect of PTSD on telomere length — in other words, the subjects with shorter telomere length may have PTSD dating from their childhood traumas, in addition to PTSD acquired in adulthood,” he added.
Researchers plan to conduct further studies. According to O’Donovan, since the volunteers without PTSD did not in general experience high levels of childhood traumas, the authors were “unable to tease apart the relative contributions of childhood trauma and adult PTSD to shorter telomere length.”
Therefore, researchers plan to investigate telomere length in subjects with and without childhood trauma and with and without PTSD in adulthood.
“A major question is whether we can actually have an effect on telomere biology by treating PTSD,” said Neylan. “If we successfully treat PTSD, can we slow the rate of telomere shortening, and thereby decrease or at least postpone the risk for some diseases of aging?”
The study is published in Biological Psychiatry.
Source: University of California