A study has found a drug that could help reduce the brain's ability to recall painful memories. According to University of Montreal researchers, recalling painful memories while under the influence of the drug metyrapone reduces the brain''s ability to re-record the negative emotions associated with them.The study, by the team at the Centre for Studies on Human Stress of Louis-H Lafontaine Hospital, challenges the theory that memories cannot be modified once they are stored in the brain.
"Metyrapone is a drug that significantly decreases the levels of cortisol, a stress hormone that is involved in memory recall," lead author Marie-France Marin explained.Manipulating cortisol close to the time of forming new memories can decrease the negative emotions that may be associated with them.
"The results show that when we decrease stress hormone levels at the time of recall of a negative event, we can impair the memory for this negative event with a long-lasting effect," Dr. Sonia Lupien, who directed the research, said.Thirty-three men participated in the study, which involved learning a story composed of neutral and negative events.
"We found that the men in the group who received two doses of metyrapone were impaired when retrieving the negative events of the story, while they showed no impairment recalling the neutral parts of the story," Marin explained.
"We were surprised that the decreased memory of negative information was still present once cortisol levels had returned to normal," she stated.
The research offers hope to people suffering from syndromes such as post-traumatic stress disorder."Our findings may help people deal with traumatic events by offering them the opportunity to "write-over" the emotional part of their memories during therapy," Marin added.
One major hurdle, however, is the fact that metyrapone is no longer commercially produced. Nevertheless, the findings are very promising in terms of future clinical treatments.