i worked as secretary in a mental health office and one of the ts did emdr. i called it the miracle cure. a little boy setting fires, one session, lost the urge entirely. a shopaholic. couple sessions, no more shopping. she glowed. i chased her down to find out what was different about her. basically when a trauma happens, your brain doesnt know how to process it. so all those chemicals created just sit there in your brain, bundled up. anytime anything happens familiar to that bundle, it retriggers that bundle of chemicals. ptsd. emdr, the process you are walked thru, unbundles that and processes it, tells it where to go in your brain. so nothing left to trigger.