In doing some reading today I stumbled across a disorder called Cerebellar Cognitive Affective Syndrome (CCAS), aka Schmahmann's Syndrome, which has some similarities to Depersonalization-Derealization. Here are a few links about the disorder:
The four main categories of symptoms are executive functioning (planning, organizing, shifting from one task to another, verbal fluency and working visual memory), spacial cognition (impaired visual-spacial memory and recognition), personality changes (flattening or blunting of affect and inappropriate behavior) and linguistic impairments (trouble with speech inflections, word organization, vocal tone, etc.).
Personally, I identify with quite a few of these, especially set shifting (switching from one task fluidly to the next), visual memory, spacial recognition, personality changes and problems with speech. Even symptoms I don't necessarily struggle with I still relate to, like desiring to be inappropriate and acting childish from time to time, which only came about when I got DP.
Guess I just thought this was interesting. I'm sure there are plenty here who can relate, and perhaps some who may even have this condition more than DP. Either way, there's quite a few similarities and reading about this condition made me wonder if perhaps the cerebellum holds the answer to understanding DP.