There seem to be a million experiments and projects going on in this vein, and I've linked to articles regarding a bunch of them over the last however-many-years. But what the hell. Here's one more!

Soldiers haunted by scenes of war and victims scarred by violence may wish they could wipe the memories from their minds. Researchers at the Johns Hopkins University say that may someday be possible.

A commercial drug remains far off — and its use would be subject to many ethical and practical questions. But scientists have laid a foundation with their discovery that proteins can be removed from the brain's fear center to erase memories forever. (Source)