Scientists have discovered a drug that could erase fearful memories in humans.
The method, using existing blood pressure pills, could be useful for weakening or erasing bad memories in people with post-traumatic stress disorder, the researchers say.
Unfortunately, other research has shown, bad memories stick better than good ones.
Studies in animal models have shown that fearful memories sometimes change when recalled, a process known as reconsolidation, and that this reconsolidation stage is vulnerable to the blood pressure drugs, called beta-adrenergic receptor blockers.
In the new study on humans, by Merel Kindt and colleagues at University of Amsterdam in The Netherlands, 60 subjects were taught to associate pictures of spiders with a mild shock, creating a fearful memory. Later, they were given either a beta-blocker called propranolol or a placebo.
The group given propranolol had a greatly decreased fear response to the spider pictures 24 hours later, according to a synopsis of the work from the journal Nature Neuroscience. And the fear response did not return, suggesting that their fear memory was completely erased.
Some ethicists see problems, question whether such treatments begin to alter what it means to be human.
“An interesting complexity is the possibility that victims, say of violence, might wish to erase the painful memory and with it their ability to give evidence against assailants,” said professor John Harris, an expert in biological ethics at the University of Manchester, in an article in the Daily Mail. “Similarly criminals and witnesses to crime may, under the guise of erasing a painful memory, render themselves unable to give evidence.”
Meantime, scientists are zeroing in on how fear grips the mind.
In 2005, researchers found a fear-factor gene that helps distinguish between people who have no fear and those who are afraid of everything. And last fall, scientists discovered the glue that keeps fearful memories stuck in the brain, a protein called beta-catenin that helps long-term memories solidify.
There’s apparently a natural way to rid yourself of bad memories, too. A 2007 study involving brain scans found that test subjects had the ability to suppress specific memories at a particular moment in time through repeated practice.