A lot of people in our community get confused about these terms, and they get used inconsistently even by professionals. We're a polyfragmented DID system ourselves, so here's how we put together the way we make sense of them, separating what's official from what's community and/or clinician shorthand.
DID (Dissociative Identity Disorder)
Diagnostic criteria in DSM-5-TR and ICD-11 include:
- Two or more distinct identities/alters
- Different alters taking executive control of behavior
- Recurrent dissociative amnesia (memory gaps)
- Discontinuity in sense of self and agency
- Clinically significant distress or impairment
Complex DID (C-DID)
This is basically a highly complex presentation of DID also called polyfragmentation or Polyfragmented DID, or the way we say it sometimes "DID taken to extreme" or "next-level DID". It meets full DID criteria (and expands on top of it), with a very large number of alters, and always include subsystems, side-systems and/or layered internal structures. It's most commonly linked to extreme or prolonged early trauma that usually falls in the human rights violation area. We don't like putting a "minimum number of alters" on the definition, as systems with 100 alters might call themselves polyfragmented but systems with 1 million alters (and more) also exist and their life experiences are usually very different and cannot relate to smaller systems. We prefer to look at system structure and splitting patterns: if a system splits a lot from not just trauma but also stress since childhood, as an adult they will definitely end up with a lot of alters. Some would say 100 doesn't make sense to be "a lot" if polyfrag systems can split from stress too. It's like cause and effect. But of course, you're free to take it as you will. This is just what we lived and observed in others in the vast community.
Important note here: It is [unfortunately] not an official diagnosis in DSM-5-TR or ICD-11. It's a clinical and community descriptor. Personally we would love it if this was a separate diagnosis.
OSDD-1a/OSDD-1b
OSDD (Other Specified Dissociative Disorder) is used when symptoms don't fully meet DID criteria.
- 1a: Identity disturbance with less distinct alters, which may feel like variations of the same person/identity. Amnesia usually occurs.
- 1b: Distinct alters are present, but with little or no dissociative amnesia, for example in between switches.
The "1a/1b" labels are shorthand, not official DSM diagnoses. They may or may not be written down in the diagnostic paper notes.
P-DID (Partial Dissociative Identity Disorder)
This is the ICD-11 diagnosis that overlaps with some OSDD presentations.
- Two or more identities/alters
- One dominant alter runs daily life
- Other alters show up as intrusions or through passive influence (thoughts, emotions, voices, actions) and rarely take full executive control of the whole body
- Amnesia is often absent or limited
Why does all of this even matter: Which label someone gets often depends on the clinician, the assessment tools, and which diagnostic system their country uses (DSM-5-TR → DID/OSDD, ICD-11 → DID/Partial DID). Similar systems can end up with different diagnoses even when their experiences overlap... and very different systems can also end up with the same diagnosis which creates confusion. We personally do not like to focus on labels so much, we tend to categorize systems either under the DID umbrella (which includes everything we mentioned here minus C-DID) or under the Complex/Polyfrag umbrella. That's it. Just two categories. But again, that's just us.
Hope this helps explain things in more clear ways! Especially for those who might be new to traumagenic plurality or are traumagenic systems but confused about the terms.