Home' Trinidad and Tobago Guardian : April 27th 2017 Contents B34 body & soul
guardian.co.tt Thursday, April 27, 2017
PTSD risk may be passed
down through our DNA
Can a war veteran pass on the trauma of the war to
his unborn children? Christal Presley whose father
was a war veteran and she has been diagnosed with
post traumatic stress disorder (PTSD). Over the next
two days, we look at the findings from a new study
that adds evidence to a possible genetic risk for de-
Christal Presley considers herself a survivor of the
Vietnam War, even though the war ended years before
she was born.
Her father was a Vietnam veteran with post-trau-
matic stress disorder, or PTSD. At times, he carried his
rifle through the house, threatening to shoot himself
in the head.
During and after the war, he used alcohol to numb
the pain, as Presley grew up, so did she.
"I've always felt like I inherited this sadness that
wasn't my own," said Presley, 38, now a teacher in
Presley was diagnosed with PTSD in 2010, and the
idea that trauma can be passed down generations has
long hit close to home.
A study published today in Molecular Psychiatry
sheds new light on why some people might develop
PTSD and others don't. For some, the key might lie
in their DNA.
Trauma is exceedingly common, but "some people
seem to be very resilient to it, and some people seem
to struggle with it," said Karestan Koenen, professor
of psychiatric epidemiology at the Harvard TH Chan
School of Public Health, who led the study.
For those who develop PTSD, the fear and stress
of trauma doesn't go away.
When the stress becomes chronic, people may
re-experience traumatic events in the form of night-
mares and flashbacks, according to the National In-
stitute of Mental Health. Presley said that she had
nightmares of war, even though she never saw it
Yehuda, another of the study's authors, was an early
researcher of trauma and heritability. Her research
on Holocaust survivors found that "epigenetic"
changes---not the genes themselves, but how they
are turned on and off by other molecules---could be
passed down to survivors' children and change their
Past studies on twins with PTSD suggested that
DNA played a major role in the disorder, but those
studies didn't look at the genes themselves, Koenen
said. That's where this study comes in.
For this study, a consortium of researchers com-
bined data from 11 studies into a single pool to explore
genetic risk for PTSD among more than 20,000 peo-
ple. They also compared that risk with other psychiat-
ric conditions and found, for example, a strong overlap
between PTSD- and schizophrenia-associated genes.
While the vast majority of the people in the study
had experienced trauma, only a quarter of them had
been diagnosed with PTSD.
Using common genetic markers, the study found
evidence of a genetic risk for PTSD, but Koenen said
she would need an even bigger group of people to
identify the specific genes involved.
Her goal for the next study is to include up to 75,000
people, with roughly a third carrying a diagnosis of
One key finding was a 29 per cent heritability of
PTSD for European-American women in the study. In
other words, three out of 10 PTSD diagnoses among
these women exposed to trauma could be linked to
common genetic variants. Women are known to be
twice as likely as men to develop PTSD after a trau-
Christal Presley was born after the Vietnam War but
has been affected by it through her father, a veteran
But for white men and all Afri-
can-Americans, the researchers were
unable to tease out statistically signif-
icant results from their DNA --- even
though African-Americans comprised
roughly half of the people in the study.
This may be because prior research has
largely focused on white populations,
the authors noted.
The difference between men and
women in this study may not be en-
tirely explained by gender, Koenen said.
Many men in the study, but very few
women, came from the military---where
service members may have experienced
very different types of trauma from the
general population, she said. (cnn.com)
• Continues tomorrow
Links Archive April 26th 2017 April 28th 2017 Navigation Previous Page Next Page