5
50960
"Drug believed to ease pain from traumatic memories" by Peter Gorner.
Armed with new information about how brain chemicals affect the storage
and
retrieval of memories, scientists are racing to help people tortured by
searing recollections of traumatic events.
Military combat, rape, bombings, burns, beatings - these experiences
can
lead to post-traumatic stress disorder, or PTSD, in which the sufferer
relives the event over and over to devastating effect, sometimes many
years
after the fact.
There is no definitive treatment for PTSD and no cure, and the number
of
cases is only expected to grow as a result of U.S. military action
overseas.
Last week, published research found that 12 percent of soldiers
returning
from Iraq were diagnosed with post-traumatic stress disorder,
depression or
another serious mental illness.
Brain scientists think they have found a way to help by using a drug
called
propranolol to alter traumatic thoughts. It appears that the drug, a
beta
blocker used to treat blood pressure, interferes with stress hormones
in the
brain to defuse the impact of horrific memories.
While use of the drug for this purpose has not been approved, some
psychiatrists already have begun to prescribe it off-label to patients
with
PTSD. (Other beta blockers do not seem to affect the brain the same
way.)
Researchers emphasize that the drug can lower the intensity of a bad
memory
but not erase it. "It's not that people will no longer remember the
trauma,
but the memory will be less painful," said Alain Brunet, a psychologist
at
McGill University in Montreal, where experiments on human subjects are
under
way.
If the drug works on PTSD, experts say it also might help with drug
addiction, stage fright, trembling, epilepsy and other conditions
caused by
changes in the brain's wiring.
The idea that a drug could affect memory flies in the face of a century
of
scientific belief. The thinking was that memories exist in an unstable
state
only for a short time; after roughly six hours, they get "consolidated"
and
stay that way forever.
But Karim Nader, a pioneering McGill psychologist, was able to show
that
long-term memories aren't nearly as hardwired as scientists had
thought.
When we retrieve a memory, Nader found, it again enters a vulnerable
state
where it could be manipulated or even lost.
"It was formerly thought that once a memory is fixed you can't mess
around
with it," said Nader. "That was scientific dogma for 100 years."
The brain's wiring changes each time something goes into long-term
memory,
but not all memories are equal, he said. "You remember the day of your
wedding better than three Tuesdays ago when there was nothing important
going on."
Emotional memories, Nader said, activate a second process that ups
their
intensity. This is called a "gain switch" and can be thought of as the
volume control on a radio.
Studies have shown that emotionally arousing events cause
stress-related
hormones such as adrenaline to be released by the brain's amygdala,
which is
involved in emotional learning and memory. PTSD may develop when the
event
is so emotionally powerful, and so much adrenaline is released, that
the
"gain switch" is set too high.
Then, each time the traumatic experience is recalled, the amygdala
releases
yet more hormones and intensifies the stressful memories even more.
"You can't control the memory. It's always invading your
consciousness,"
Nader said.
Propranolol throws a wrench into that self-perpetuating system by
interfering with the amygdala's receptors and allowing victims to
maintain a
level of memory similar to that of a bystander.
Nader and his colleagues have demonstrated this effect in rats. When
the
researchers reactivated a fearful memory in the rats, such as by
putting
them in a cage where they had previously been shocked, the animals who
were
given propranolol were no longer afraid.
Now the team is doing an experiment on men and women with
post-traumatic
stress disorder. The subjects are fitted with headphones so they can
listen
to recordings of their own descriptions of traumatic events they went
through.
Palm sweat, heart rate and other changes are measured to determine
whether
the physiological response to the traumatic story is less among those
who
took propranolol than among those given a placebo.
The study is not complete, but the researchers say they're "encouraged
and
excited" with the early results. "People with PTSD tell me their life
is so
miserable, they're willing to try anything to feel better," Brunet
said.
"I'm amazed that what seemed to be science fiction just a few years ago
is
being tested. So this is a really big move forward."
Any ideas? I know this is a lipophilic B-blocker, but is it slowing down overactivity in the HPA axis?
Give it a shot Dr. Poety 🙂
Armed with new information about how brain chemicals affect the storage
and
retrieval of memories, scientists are racing to help people tortured by
searing recollections of traumatic events.
Military combat, rape, bombings, burns, beatings - these experiences
can
lead to post-traumatic stress disorder, or PTSD, in which the sufferer
relives the event over and over to devastating effect, sometimes many
years
after the fact.
There is no definitive treatment for PTSD and no cure, and the number
of
cases is only expected to grow as a result of U.S. military action
overseas.
Last week, published research found that 12 percent of soldiers
returning
from Iraq were diagnosed with post-traumatic stress disorder,
depression or
another serious mental illness.
Brain scientists think they have found a way to help by using a drug
called
propranolol to alter traumatic thoughts. It appears that the drug, a
beta
blocker used to treat blood pressure, interferes with stress hormones
in the
brain to defuse the impact of horrific memories.
While use of the drug for this purpose has not been approved, some
psychiatrists already have begun to prescribe it off-label to patients
with
PTSD. (Other beta blockers do not seem to affect the brain the same
way.)
Researchers emphasize that the drug can lower the intensity of a bad
memory
but not erase it. "It's not that people will no longer remember the
trauma,
but the memory will be less painful," said Alain Brunet, a psychologist
at
McGill University in Montreal, where experiments on human subjects are
under
way.
If the drug works on PTSD, experts say it also might help with drug
addiction, stage fright, trembling, epilepsy and other conditions
caused by
changes in the brain's wiring.
The idea that a drug could affect memory flies in the face of a century
of
scientific belief. The thinking was that memories exist in an unstable
state
only for a short time; after roughly six hours, they get "consolidated"
and
stay that way forever.
But Karim Nader, a pioneering McGill psychologist, was able to show
that
long-term memories aren't nearly as hardwired as scientists had
thought.
When we retrieve a memory, Nader found, it again enters a vulnerable
state
where it could be manipulated or even lost.
"It was formerly thought that once a memory is fixed you can't mess
around
with it," said Nader. "That was scientific dogma for 100 years."
The brain's wiring changes each time something goes into long-term
memory,
but not all memories are equal, he said. "You remember the day of your
wedding better than three Tuesdays ago when there was nothing important
going on."
Emotional memories, Nader said, activate a second process that ups
their
intensity. This is called a "gain switch" and can be thought of as the
volume control on a radio.
Studies have shown that emotionally arousing events cause
stress-related
hormones such as adrenaline to be released by the brain's amygdala,
which is
involved in emotional learning and memory. PTSD may develop when the
event
is so emotionally powerful, and so much adrenaline is released, that
the
"gain switch" is set too high.
Then, each time the traumatic experience is recalled, the amygdala
releases
yet more hormones and intensifies the stressful memories even more.
"You can't control the memory. It's always invading your
consciousness,"
Nader said.
Propranolol throws a wrench into that self-perpetuating system by
interfering with the amygdala's receptors and allowing victims to
maintain a
level of memory similar to that of a bystander.
Nader and his colleagues have demonstrated this effect in rats. When
the
researchers reactivated a fearful memory in the rats, such as by
putting
them in a cage where they had previously been shocked, the animals who
were
given propranolol were no longer afraid.
Now the team is doing an experiment on men and women with
post-traumatic
stress disorder. The subjects are fitted with headphones so they can
listen
to recordings of their own descriptions of traumatic events they went
through.
Palm sweat, heart rate and other changes are measured to determine
whether
the physiological response to the traumatic story is less among those
who
took propranolol than among those given a placebo.
The study is not complete, but the researchers say they're "encouraged
and
excited" with the early results. "People with PTSD tell me their life
is so
miserable, they're willing to try anything to feel better," Brunet
said.
"I'm amazed that what seemed to be science fiction just a few years ago
is
being tested. So this is a really big move forward."
Any ideas? I know this is a lipophilic B-blocker, but is it slowing down overactivity in the HPA axis?
Give it a shot Dr. Poety 🙂
