Forgetting fear

The Times has an excellent article summarising recent research on the possibility of treating traumatic memories by tempering their impact either just after the event or when remembering the experience at a later point.

The ability to update our memories with new information highlights the flexibility of our brain. Every act of remembering gives us an opportunity to shape memories, or even erase them. The discovery of the reconsolidation window has kick-started a lot of new memory research, advances in which could have important implications for people who suffer from unwanted fearful memories. Potential treatments for anxiety, phobias or post-traumatic stress disorder (PTSD) may be close at hand.

It’s a remarkably wide-ranging article that covers both chemical and psychological methods that have been drawn from recent research and is probably the best concise summary of this research you’ll be likely to read for a good while.

Much of the initial interest in this area was on a drug called propranolol, that doesn’t affect the brain’s memory circuits directly but does reduce tension in the body. Several experiments showing it reduced traumatic responses when taken immediately after a severe event generated a lot of hope that it might be a new way of preventing catastrophic reactions.

Recent findings have dulled the excitement a little though, as two studies have come out on burns victims, one in soldiers and another in children, and the drug had no detectable effect on trauma.

The Times article also mentions that “the drug merely changes the emotional content of memories, rather than erasing them” although this point is controversial.

Some studies that have tested the effect on recalling tragedy or trauma stories have found a genuine reduction in the amount of information recalled, not only the emotional ‘kick’ of the memories.

One similar study didn’t find this effect and a recent experiment directly compared propranolol to placebo and the stress hormone cortisol and found no effect of propranolol on memory, but another study found it did reduce short-term memory overall although it also lessened the impact of emotional distractions.

This is an important issue, because, as The Times notes, it could have massive implications if memories of a traumatic event form part of a court case after the drug may have ‘tampered’ with the evidence.

The piece by Ed Yong and Alice Fishburn, the former who you may know from the Not Exactly Rocket Science blog and who has put an added an interview with neuroscientist Todd Sacktor online who has completed recent work on the role of the PKMzeta protein in memory.

Link to Times article ‘How to forget fear’.
Link to NERS interview with Todd Sacktor.