Traumatic events have a habit of leaving sharp imprints on victims’ minds and these memories can be triggered off by innocuous stimuli leading to an overwhelming response characterized by increased heart rate and breathing difficulties. Such a condition is called as Post-traumatic stress disorder or simply PTSD.
The treatment of this condition is at best supportive in that counseling had been known to have a calming effect on affected individuals. But all that could change now as researchers at the Cornell University in New York have fund that a drug used to lower blood pressure can block unpleasant memories as well.
This drug, propranolol, belongs to a group of drugs called the beta-blockers which are commonly prescribed to individuals suffering from high blood pressure. The researchers found that propranolol also blocks certain neurotransmitters, which are vital in storing memories. They sensitized rats to a tone following which an electric shock was given to them.
These rats began anticipating the shock after the tone and started demonstrating a hyperactive response to it. But if they were given propranolol prior to the shock therapy, researchers found that their fear of the shock vanished. The Cornell University researchers have reported similar findings in humans as well, "The memory of the event is associated with the fear, and they always occur together. Our expectation is that we're reducing the hyperarousal associated with the memory -- we expect that the memory will still be there," states lead researcher Dr Margaret Altemus, an associate professor of psychiatry at the Weill College of Medicine at Cornell University.
She explained that there was a precedent in the use of propranolol in two small studies in France and Boston, "They did find they were able to reduce the emotional intensity of traumatic memories by giving people propranolol for the first 10 days or so after an accident," Altemus said.
However, she was quick to point out the PTSD does not occur in all individuals who were witnesses to catastrophic events like the recent London bombings. The condition is estimated to occur in about 10 percent of the victims. Hence, it was not mandatory that everyone who was associated with traumatic events be given propranolol.
She also said that the next step was to conduct a bigger trial with around 60 subjects. However, only one person has volunteered for the trial so far. The study, which is sponsored by the National Institute of Health, has come under fire from several experts who believe that the drug had a massive potential for misuse as it could be given to people who had committed atrocities.
One such critic Dr Paul McHugh, a psychiatrist at Johns Hopkins University said, "If soldiers did something that ended up with children getting killed, do you want to give them beta blockers so that they can do it again?" To this Dr Altemus argues, "If you take someone who has been in the Holocaust or was raped -- their ability to change laws or prevent that event from happening again is actually inhibited by having PTSD. People are able to be themselves and be more active if they don't have it."
The details of the propranolol study are published in the latest issue of the journal Nature.
