OE's advice is excellent and I relate to it very much.

I find that distraction works best for me. I counter episodes with lively music and try to fend them off with meditative music (especially alpha-wave CDs).

Reading can sometimes be a trigger. I've been reading spiritual self-help books lately which seem to help. Also, I find magazines to be a good distraction too. I like to read newspapers but they are often triggering - especially current events.

I no longer take long walks as my mind also wanders to bad things when I do. I could use the exercise so this is a big problem for me.

Let us know what you try and what works for you. We will all benefit from your findings.