Drug gets rid of those nasty memories

A team of scientists say they have found a way to dampen down the impact of bad memories in people's brains.

Canadian and American researchers used a drug called propranolol, often used to treat heart patients, to target unwanted memories, while leaving others intact.

The researchers from McGill University, in Montreal, and Harvard University in Boston, injected the drug into volunteers who were then asked to recall a painful memory.

The drug appeared to disrupt the way the memory was stored and the team are optimistic that their work could lead to new treatments for patients with psychiatric disorders, such as post-traumatic stress.

Experts have however expressed alarm and say fear reactions are there to protect people from danger in the future and are they are concerned that the treatment is wide-open to abuse.

The research however is still in it's infancy and experts say much more work is needed to demonstrate that it could lead to tangible benefits and gain an understanding of the long term effects of the drug.

The researchers tested the treatment on 19 victims of vehicle crash or rape over a 10 day period; the volunteers were given the drug, or a placebo and then asked to recall their memories of a traumatic event that had happened 10 years earlier.

A week later the researchers found that those people who were given a shot of propranolol showed fewer signs of stress, such as raised heart rate, when recalling their trauma.

The researchers suggest that memories are initially stored in the brain in a malleable, fluid state before becoming hard-wired into the circuitry and when they are recalled, they once again become fluid and capable of being altered.

They believe propranolol disrupts the biochemical pathways that allow a memory to "harden" after it has been recalled and say the findings suggest that memories can be manipulated.