Drug eases pain of bad memories March 3, 2006 By Peter Gorner /Tribune science reporter 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. .../Kodsh, today's Chicago Tribune: . re Inderal & Ptsd - finds memories gone, so people are asking for it for that.
[the drug propranolol - Inderal - a medication sometimes used in the treatment of panic and anxiety disorders]
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 high 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 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.
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.

Emotional memories, Nader explained, activate a second process that ups their intensity. This is called a "gain switch." 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. Propranolol throws a wrench into that self-perpetuating system by interfering with the amygdala's receptors and ultimately allowing victims to maintain a level of memory similar to that of a bystander. whoa. 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. ~hm. 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 vivid descriptions well -good method 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.
Dr. Roger Pitman, a professor of psychiatry at Harvard Medical School, wondered if giving propranolol as soon as possible after a traumatic event could prevent indelible, terrifying memories from taking hold.He tested the idea on 41 people who had experienced car accidents, assaults and other events that brought them to a Massachusetts emergency room. They received the drug within six hours of their mishaps.The results were dramatic. Three months later, 22 of the victims listened to audiotapes on which they had described their traumas. None of those who took propranolol showed strong responses to the tapes, but eight of the placebo patients were obviously shaken by reliving their experiences. Their heart rates increased, their palms sweated, their muscles twitched--all signs of PTSD.
The scientists acknowledge that any treatment involving "therapeutic forgetting" is controversial. Some ethicists worry that such treatment may numb us and make us less capable of handling psychological pain. Others contend that random traumas and horrific memories of wartime combat serve no purpose and are best forgotten.
But the brain researchers emphasize that they are not trying to erase people's memories. "Many people have thought of these as amnesia drugs: `I would like to get rid of the memory of a horrible experience I had with another person; I'll just take propranolol and get rid of it,'" said James McGaugh, a neurobiologist at the University of California at Irvine whose work on learning and memory paved the way for research by Pitman and others. "Well, propranolol does not remove memories." The day after Nader's first study was published, a woman called and asked whether she could have the memories of her abusive first husband erased. "The idea of erasing memory is just silly," Nader said. "We can't do it; nor do we want to. But if we can turn down the intensity of the memory sufficiently that these patients can respond to traditional treatments, that's the goal, I think."