There is a piece on NPR today:
http://www.npr.org/templates/rundowns/rundown.php?prgId=2
It talks about research using a beta-blocker drug (propenanol?) that appears to erase or ease scary or painful memories with a learned fear response.

The notice says the audio segment will be posted after 7 pm today.

Here is the link:
http://www.npr.org/templates/story/story.php?storyId=100754665

Having listened to the audio segment, it sounds like the effect of the drug is akin to when people dissociate. When I think about something frightening, my emotions deaden and I am able to deal with it. It sounds as if the drug does the same thing, with the same potential side-effect. I have trouble feeling much of anything most of the time, particularly strong emotions. The drug could potentially weaken the portion of the brain that induces strong emotional responses.

I understand the reason behind wanting to use such a drug, but what if the effects are not reversible?