I think the only way is the trial-and-error approach, the "meditation roulette" - trying one drug after another and hoping that something works.
SSRIs are ineffective in most cases, but they are well tolerated in many people so it might not be a bad idea to check out if you are an exception. The same goes for SNRI (Duloxetine or Venlafaxine). Then you could try Clomipramine. There are some credible cases both in the literature and on this forum, where it was effective, but we do not know if the response rate is really higher than SSRIs.Of course, since what works for another person may not work for me, but I don't even know where to start!
I think only supplements that are sometimes used to treat schizophrenia would make sense in DP. This would be something like glycine, Sarkosin and Acetylcystein. If there is a deficency it's another story.I was hoping for sorta non-prescription supplements, but thanks anyway