A commonly prescribed medication for lowering blood pressure may also help people forget bad memories. A report appearing online February 15 in Nature Neuroscience shows that taking the beta-blocker drug propanolol before recalling a fearful memory may help rid people of the fear associated with that memory. If true, the drug might be able to help people with anxiety, post-traumatic stress disorder (PTSD) or other emotional disorders.

The researchers showed 60 participants a picture of a spider, while at the same time exposing half of them to a mild electric shock. Then they measured the fear the participants had learned to associate with the spider picture by measuring their startle response to a puff of air; participants not given any shock showed no fear, while those who had been shocked showed significant fear associated with the spider picture.

Next, the researchers gave some of the participants propanolol before showing them the picture again. This time, those who had formerly been fearful of the spider picture showed a much smaller fear response, or even none at all. When tested again the following day, after the propanolol was no longer present in the participants’ bodies, the participants continued to show no fear of the spider picture, despite being able to remember having seen the picture before.

While it may seem like your memories are static video camera versions of the past, in actuality memories are changing all the time. Anytime you remember something, the process of recalling that memory from storage and then "re-filing" it back into storage alters the memory slightly. This process of re-filing memories is called reconsolidation, and researchers have previously showed that during reconsolidation, memories are very sensitive to the effects of certain drugs.

In the present study, giving the participants propanolol while they recall a fearful memory may interrupt this process of reconsolidation. The beta-blocker may interfere with the brain neurotransmitters that are involved in reconsolidation of the emotional component of the memory, but leave the rest of the memory intact, the scientists suggest. The memory of the picture is still there, but it is no longer associated with fear. If the effect works for people with anxiety disorders, they would still remember a traumatic event but the negative emotional associations may be dulled or gone altogether.

The researchers caution that much more study is required before it can be used in patients who have suffered emotional trauma. The next steps are to look at how long the drug's effects on memory last, and examining if the treatment works in people who are suffering from some kind of disorder or phobia. The study authors also note that beta-blockers likely have an effect on the reconsolidation of all memories, not just fearful or traumatic ones.

Want to learn more about anxiety disorders? Read the Healia Health Guide on Anxiety or the Healia Health Guide to PTSD. To connect with other people interested in these disorders, join the Healia Heath Community for Anxiety or the Healia Health Community for PTSD.

_{Photo: Yankee November, Flickr, Creative Commons}