One possible cause of DPDR that is altered hormone levels after a concussion due to damage to the HPA axis. There is a video of a guy who cured his DPDR after a year of testosterone replacement therapy on Youtube. I cannot post links but it will show up with a search of "dpdr and hormones" on Youtube.

I am clinging on to the hope that this is the cause of mine, not seizures, because it is truly debilitating.

I realize that this an old thread, and that goodgrief20 is likely gone from the forum, but when I read through I thought I must post, because I've been experiencing something very similar to what goodgrief described, and also because it seems that goodgrief is a similar thinker to myself. Reading the words they wrote, I could see myself expressing myself and describing the situation the same way. I'm about six months out from the injury - sustained in a car crash. For the first few months, I felt a near-complete depersonalization similar to what goodgrief described. Since then I've been able to integrate more to an extent. I've been back at my (mentally demanding) work for a month, and I'm getting through it ok, but a job that I used to find easy is now very demanding and taking up most of my energy.

I still feel very dissociated. It feels like my consciousness, my thoughts, my perceptions, and my emotions are all disconnected from each other. They are still happening, but there is little integrated connection. And I feel the same feeling of mental blankness, with little inner dialogue. It's like my mind can still do a lot of things, but I can't "feel" it doing those things, feel disconnected from it, and my consciousness has to actively recruit my mind to do the things it wants, which can be difficult and tiring.

I might come back and describe my sensations and situations in more depth later. Also curious if anyone is feeling similar things.