From a comment elsewhere by "Brian" on moving past psychological trauma:
http://www.hughhowey.com/our-silos-leak/
"Cognitive behavioral therapists don’t even bother trying to figure out the why — because when most people get their so-called “epiphany” explaining why they’re feeling so badly, the knowledge doesn’t give them any clue as to how to feel better and be happy. All they know is, X and Y and Z happened to me many moons ago, and that’s why I feel like crap now. But what do I actually do about it?
Bandler and Grinder figured it out forty plus years ago during the infancy of NLP too: focus on what you want, focus on what makes you happy, model people who are successful and happy and voila …. you’ll move in that direction too. Like you said above, Hugh, thinking about something that bothers you over and over is just another way of reexperiencing the pain and torment. Unless you’re coming at the memory from a fresh perspective, it’s like rubbing salt in the wound."
So, if a drug like MDMA helps someone see a memory from a fresh perspective, maybe it could help? But otherwise, the general advice above seems useful.