Traumatic memories can reverberate for many years after the experience. Now, researchers reveal that sedation can actually ease the sting of emotionally disturbing memories.

This offers hope that a general anesthetic will someday be able to help people with post-traumatic stress disorder (PTSD) deal with harrowing memories.

Researchers Find Propofol Can Relieve Painful Memories

The new study, published in the journal Science Advances, shows that when volunteers were given a dose of sedative propofol immediately after remembering a traumatic story, the story becomes less distressing 24 hours later.

One of the keys of the potential treatment is the discovery that memory can be altered every time it is recalled. Knowing this, the team behind the new study wanted to see whether a sedative can affect the process.

The study involved 50 volunteers who were already scheduled for sedation for a gastroscopy or colonoscopy. A week before their procedure, each were asked to memorize two stories from slide shows that started and ended neutrally, but contained upsetting scenarios in between.

Right before their sedation, the volunteers were shown the first slide of one of the stories and asked a number of questions to jog their memory of the story.

Then, immediately after their gastroscopy or colonoscopy, half of the volunteers were interviewed to determine their recollection. The group remembered the stories well.

The other half were interviewed 24 hours later and at this point, the propofol showed a distinct effect. On average, this half of volunteers were 12 percent worse at remembering the emotional details of the stories than those who were interviewed immediately after sedation.

Both groups remembered the less emotional parts of the stories equally well.

"The [brain] circuitry involved in emotional memory is probably quite sensitive to anaesthetics," Bryan Strange, study author and a neuroscientist at the Technical University of Madrid, explains in New Scientist. "This is good for a potential treatment because you don't want to remove information that isn't dramatic or unwanted."

Potential Of Sedatives For PTSD

Study authors hope that their findings pave the way for treating PTSD patients.

Previous studies have tried treating PTSD with other techniques, such as electroconvulsive therapy, according to Live Science. However, an anesthetic treatment will offer a far less invasive alternative for patients.

Ana Galarza Vallejo, study author and a neuroscientist at the Technical University of Madrid, tells Live Science that it's just a matter of time before their team tries to treat PTSD with anesthesia.

However, scientists note that PTSD is far more complex than the simple memory scenarios used in the study.

Strange points out in New Scientist that older memories are likely less susceptible to change. Ongoing flashbacks will also probably require more complicated treatment.