This segment was originally broadcast on Nov. 26, 2006. It was updated on June 14, 2007.
If there were something you could take after experiencing a painful or traumatic event that would permanently weaken your memory of what had just happened, would you take it? As correspondent Lesley Stahl first reported last fall, it's an idea that may not be so far off, and that has some critics alarmed, and some trauma victims filled with hope.
"I couldn't get my body to stop shaking. I was trembling, constantly trembling. Memories of it would just come back, reoccurring over and over and over," subway conductor Beatriz Arguedas recalls.
A year ago September, Beatriz was driving her normal route on the Red Line in Boston when one of her worst fears came to pass: "Upon entering one of the busiest stations, a man jumped in front of my train, to commit suicide," she explains.
Beatriz saw the man jump. "We sort of made eye contact and then I felt the thud from him hitting the train and then the crackling sound underneath the train and, then, of course, my heart starts thumping," she recalls.
"She came into our emergency room afterwards, very upset. No physical injury. Entirely a psychological trauma," says Dr. Roger Pitman, a psychiatrist at Harvard Medical School who has studied and treated patients with post-traumatic stress disorder, or PTSD, for 25 years.
"They're caught up so much with this past event that it's constantly in their mind," Pitman explains. "They're living it over and over and over as if it's happening again. And they just can't get involved in real life."
When Beatriz arrived in the emergency room, Pitman enrolled her in an experimental study of a drug called propranolol, a medication commonly used for high blood pressure ... and unofficially for stage fright. Pitman thought it might do something almost magical – trick Beatriz's brain into making a weaker memory of the event she had just experienced.
In the study, which is still under way, half the subjects get propranolol; half get a placebo.
Asked whether he knows if Beatriz got the drug or the placebo, Dr. Pitman says he has no idea and neither does she, and that the research team won't know for another two years.
If Pitman is right, the results could fundamentally change the way accident victims, rape victims, even soldiers are treated after they experience trauma.
The story begins with some surprising discoveries about memory. It turns out our memories are sort of like Jello – they take time to solidify in our brains. And while they're setting, it's possible to make them stronger or weaker. It all depends on the stress hormone adrenaline.
The man who discovered this is James McGaugh, a professor of neurobiology at the University of California, Irvine.