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Medical Xpress
Jan 9 2015
Study IDs two genes that boost risk for post-traumatic
Why do some people develop post-traumatic stress disorder (PTSD) while
others who suffered the same ordeal do not? A new UCLA discovery may
shed light on the answer.
UCLA scientists have linked two gene variants to the debilitating
mental disorder, suggesting that heredity influences a person's risk
of developing PTSD. Published in the February 2015 edition of the
Journal of Affective Disorders, the findings could provide a
biological basis for diagnosing and treating PTSD more effectively in
the future.
"Many people suffer with post-traumatic stress disorder after
surviving a life-threatening ordeal like war, rape or a natural
disaster," explained lead author Dr. Armen Goenjian, a researcher at
the Semel Institute for Neuroscience and Human Behavior at UCLA. "But
not everyone who experiences trauma suffers from PTSD. We investigated
whether PTSD has genetic underpinnings that make some people more
vulnerable to the syndrome than others."
In 1988, Goenjian, an Armenian American, raced to Spitak, Armenia,
after a 6.8 magnitude earthquake devastated the country. The temblor
leveled entire towns and cities, killing more than 25,000 Armenians,
two-thirds of them children.
With support from the Armenian Relief Society, Goenjian and his
colleagues helped establish a pair of psychiatric clinics that treated
earthquake survivors for 21 years. A dozen multigenerational families
in northern Armenia agreed to allow their blood samples to be sent to
UCLA, where Goenjian and his colleagues combed the DNA of 200
individuals for genetic clues to psychiatric vulnerability.
In 2012, his team discovered that PTSD was more common in survivors
who carried two gene variants associated with depression. In the
current study, Goenjian and first author Julia Bailey, an adjunct
assistant professor of epidemiology at the UCLA Fielding School of
Public Health, focused on two genes called COMT and TPH-2 that play
important roles in brain function.
COMT is an enzyme that degrades dopamine, a neurotransmitter that
controls the brain's reward and pleasure centers, and helps regulate
mood, thinking, attention and behavior. Too much or too little
dopamine can influence various neurological and psychological
disorders.
TPH-2 controls the production of serotonin, a brain hormone that
regulates mood, sleep and alertness--all of which are disrupted in
PTSD. Antidepressants called SSRIs, or selective serotonin re-uptake
inhibitors, which were designed to treat depression, target serotonin.
More physicians are prescribing SSRIs to treat disorders beyond
depression, including PTSD.
"We found a significant association between variants of COMT and TPH-2
with PTSD symptoms, suggesting that these genes contribute to the
onset and persistence of the disorder," said Goenjian. "Our results
indicate that people who carry these genetic variants may be at higher
risk of developing PTSD."
The team used the most recent PTSD criteria from the American
Psychiatric Association's diagnostic manual to measure genes' role in
predisposing someone to the disorder. The new criteria increased
estimates of a person's predisposition for PTSD to 60 percent;
estimates based on older criteria reached only 41 percent.
"Assessments of patients based upon the latest diagnostic criteria may
boost the field's chances of finding new genetic markers for PTSD,"
said Goenjian. "We hope our findings will lead to molecular methods
for screening people at risk for this disorder and identify new drug
therapies for prevention and treatment."
Still, Goenjian cautioned, PTSD is likely caused by multiple genes and
studies should be continued to find more of the genes involved.
PTSD affects about 7 percent of Americans and became a pressing health
issue for a large percentage of war veterans returning from tours in
Iraq and Afghanistan.
"A diagnostic tool based upon PTSD-linked genes would greatly help us
in identifying people who are at high risk for developing the
disorder," Goenjian said. "Our findings may also help scientists
uncover more refined treatments, such as gene therapy or new drugs
that regulate the chemicals associated with PTSD symptoms."
http://medicalxpress.com/news/2015-01-ids-genes-boost-post-traumatic-stress.html
Jan 9 2015
Study IDs two genes that boost risk for post-traumatic
Why do some people develop post-traumatic stress disorder (PTSD) while
others who suffered the same ordeal do not? A new UCLA discovery may
shed light on the answer.
UCLA scientists have linked two gene variants to the debilitating
mental disorder, suggesting that heredity influences a person's risk
of developing PTSD. Published in the February 2015 edition of the
Journal of Affective Disorders, the findings could provide a
biological basis for diagnosing and treating PTSD more effectively in
the future.
"Many people suffer with post-traumatic stress disorder after
surviving a life-threatening ordeal like war, rape or a natural
disaster," explained lead author Dr. Armen Goenjian, a researcher at
the Semel Institute for Neuroscience and Human Behavior at UCLA. "But
not everyone who experiences trauma suffers from PTSD. We investigated
whether PTSD has genetic underpinnings that make some people more
vulnerable to the syndrome than others."
In 1988, Goenjian, an Armenian American, raced to Spitak, Armenia,
after a 6.8 magnitude earthquake devastated the country. The temblor
leveled entire towns and cities, killing more than 25,000 Armenians,
two-thirds of them children.
With support from the Armenian Relief Society, Goenjian and his
colleagues helped establish a pair of psychiatric clinics that treated
earthquake survivors for 21 years. A dozen multigenerational families
in northern Armenia agreed to allow their blood samples to be sent to
UCLA, where Goenjian and his colleagues combed the DNA of 200
individuals for genetic clues to psychiatric vulnerability.
In 2012, his team discovered that PTSD was more common in survivors
who carried two gene variants associated with depression. In the
current study, Goenjian and first author Julia Bailey, an adjunct
assistant professor of epidemiology at the UCLA Fielding School of
Public Health, focused on two genes called COMT and TPH-2 that play
important roles in brain function.
COMT is an enzyme that degrades dopamine, a neurotransmitter that
controls the brain's reward and pleasure centers, and helps regulate
mood, thinking, attention and behavior. Too much or too little
dopamine can influence various neurological and psychological
disorders.
TPH-2 controls the production of serotonin, a brain hormone that
regulates mood, sleep and alertness--all of which are disrupted in
PTSD. Antidepressants called SSRIs, or selective serotonin re-uptake
inhibitors, which were designed to treat depression, target serotonin.
More physicians are prescribing SSRIs to treat disorders beyond
depression, including PTSD.
"We found a significant association between variants of COMT and TPH-2
with PTSD symptoms, suggesting that these genes contribute to the
onset and persistence of the disorder," said Goenjian. "Our results
indicate that people who carry these genetic variants may be at higher
risk of developing PTSD."
The team used the most recent PTSD criteria from the American
Psychiatric Association's diagnostic manual to measure genes' role in
predisposing someone to the disorder. The new criteria increased
estimates of a person's predisposition for PTSD to 60 percent;
estimates based on older criteria reached only 41 percent.
"Assessments of patients based upon the latest diagnostic criteria may
boost the field's chances of finding new genetic markers for PTSD,"
said Goenjian. "We hope our findings will lead to molecular methods
for screening people at risk for this disorder and identify new drug
therapies for prevention and treatment."
Still, Goenjian cautioned, PTSD is likely caused by multiple genes and
studies should be continued to find more of the genes involved.
PTSD affects about 7 percent of Americans and became a pressing health
issue for a large percentage of war veterans returning from tours in
Iraq and Afghanistan.
"A diagnostic tool based upon PTSD-linked genes would greatly help us
in identifying people who are at high risk for developing the
disorder," Goenjian said. "Our findings may also help scientists
uncover more refined treatments, such as gene therapy or new drugs
that regulate the chemicals associated with PTSD symptoms."
http://medicalxpress.com/news/2015-01-ids-genes-boost-post-traumatic-stress.html