DID seems like it might just be adding to diagnostic confusion. If PTSD or Borderline PD, or panic d/o, or IED, could better explain it, why use DID. The issue is the distinct personalities and lost sense of agency. This idea just seems so far out there, that there are two or three or more alters within one person.
I mean, when I get angry, my personality changes, I don't remember things quite as clearly, and I act differently than when I'm calm. If the anger is enough, maybe I can't control myself the same as when I'm calm either. Is that an alter? Like can I say, "oh that's John, he's a real son of a bitch....I have DID. I just lose control and don't know what happens, and minutes can go by or I can find myself in a different place suddenly because he takes me over and I don't remember anything." Or could this be just as easily described as a dissociative component of one of the diagnoses above. "And when I get sad, that's when Tony shows up and it's the same thing with not remembering what I'm doing, just laying around all day, aimless and pretty soon 8 hours have suddenly been lost just sitting on the couch and I don't know what's happened."
If I were to come on to the board and question the existence of schizophrenia, everyone would think I was an idiot, or a scientologist, or that I had no experience because anyone who has worked for a month on inpatient psych has seen schizophrenia or schizoaffective disorder. The same certainly cannot be said for DID. So maybe it's just low prevalence of DID, or that it commonly travels with PTSD/borderline and gets missed, and if you're a cynic, the chances are low you would see that DID patient with a more pure (no other dx confounding) presentation and simply write it off as being from PTSD/borderline. Though uptodate says prevalence is 1.3% of population, which is slightly more than schizophrenia I believe; I'm not sure where these patients are. Perhaps if you're looking for DID, you will extend PTSD/borderline dissociation to fit the diagnosis.
Anyways, interesting topic.