* PTSD sufferers have low levels of brain chemical
* Finding may lead to drugs specifically for PTSD
By Julie Steenhuysen
CHICAGO (Reuters) - People with post-traumatic
stress disorder appear to have lower levels of a specific kind
of brain chemical known as serotonin 1B, and targeting this
with drugs could lead to the first treatments specifically
targeting the disorder, U.S. researchers said Monday.
Currently, doctors use antidepressants and anti-anxiety
drugs to treat PTSD, but these are largely ineffective and were
never specifically developed to treat the disorder, in which
trauma victims suffer from recurrent memories of trauma,
intense guilt or worry, angry outbursts and bad dreams.
"The medications we have these days are not working for
PTSD," said Dr. Alexander Neumeister of the Mount Sinai School
of Medicine, whose study appears in the Archives of General
To address this, Neumeister and a team at the Yale Positron
Emission Tomography Center used imaging to study the specific
differences in the brain between people who have PTSD and
others who have had traumatic experiences but do not have
For the study, researchers performed positron emission
tomography or PET scans of 49 PTSD patients whose conditions
arose from a variety of traumatic events, including childhood
abuse, domestic violence and military service.
Researchers also looked at the brains of 20 trauma victims
with no PTSD and 27 healthy adult volunteers.
They found that people with PTSD had changes in the
serotonin 1B receptor, a key neurotransmitter that in animal
studies appears to be especially sensitive to stress.
The researchers found that levels of serotonin 1B were
substantially lower in patients with PTSD than in healthy
patients. Levels of this neurotransmitter were also slightly
lower in the non-PTSD group who had been exposed to trauma
compared with the healthy volunteers.
And the younger a person was when the trauma occurred, the
bigger the difference.
"In those individuals who had early trauma in their life,
we found the most severe alteration in the serotonin 1B
receptor," Neumeister said in a telephone interview.
The findings, which need to be confirmed by bigger studies,
offer a first step in developing drugs specifically designed to
target brain changes that occur in people with PTSD.
"Currently, the only medical treatment options for the
nearly 8 million American adults with PTSD are anti-depressants
and anti-anxiety medications, which show little benefit in
improving the mental health of these patients," Neumeister said
in a statement.
Neumeister said several drug companies, including Eli Lilly
and Merck & Co already are exploring drugs that target this
receptor, and other drug targets are being looked at as well.
"Hopefully in the near future we will have drugs that will
interfere with this receptor," Neumeister said.
(Editing by Cynthia Osterman)
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