How does ICD‑11 define partial dissociation compared with DSM‑5 criteria for DID?
Executive summary
ICD‑11 creates a distinct diagnosis, Partial Dissociative Identity Disorder (pDID), describing cases where one personality state dominates daily functioning but is intermittently intruded upon by non‑dominant states, whereas DSM‑5 maintains a single Dissociative Identity Disorder (DID) category that requires recurrent gaps in recall and uses Other Specified Dissociative Disorder (OSDD) to capture DID‑like presentations that do not meet full criteria; importantly, ICD‑11 does not require dissociative amnesia for its DID or pDID diagnoses while DSM‑5 retains amnesia as a formal criterion [1] [2] [3].
1. What ICD‑11 calls “partial” and why it matters
The WHO’s ICD‑11 formally introduced Partial Dissociative Identity Disorder to capture the common clinical picture in which a single, dominant personality state manages most daily life but is subject to occasional intrusions by one or more non‑dominant dissociative states — intrusions that can be cognitive, affective, perceptual, motor or behavioral in character and that typically interfere with functioning [1] [4]. ICD‑11’s working groups argued this addition improved clinical utility and better accounted for presentations previously scattered under unspecified dissociative categories in ICD‑10 [5] [6].
2. DSM‑5’s approach: one DID diagnosis plus OSDD as a catch‑all
The DSM‑5 revised DID by removing older requirements that alternate personality states must recurrently take control of behavior and instead retained core features including the presence of two or more distinct identity states plus the required criterion of recurrent gaps in recall of everyday events, personal information, or traumatic events — language that makes dissociative amnesia an explicit DSM‑5 gatekeeper for DID [3] [2]. Presentations that resemble DID but lack DSM‑5’s amnesia or fully differentiated parts are typically diagnosed as Other Specified Dissociative Disorder (OSDD) in DSM‑5, with a subtype (informally OSDD‑1a) mapping closely to what ICD‑11 calls partial DID [7] [8].
3. The clearest diagnostic difference: amnesia as required vs typical
A pivotal conceptual divergence is that DSM‑5 enshrines “recurrent gaps in recall” as part of the DID diagnostic criteria, whereas ICD‑11 explicitly does not require dissociative amnesia for either DID or pDID, noting that substantial amnesia is nevertheless “typically present” over the disorder’s course for full DID and is often absent or brief/restricted in pDID [2] [1]. This distinction affects who meets each manual’s threshold and explains why many previously uncoded DDNOS/OSDD cases were reclassified as pDID under ICD‑11 [6] [9].
4. Overlap, mapping, and clinical implications
Practically, many cases that DSM clinicians code as OSDD‑1a or other nonspecific dissociative presentations will correspond to ICD‑11’s pDID: both systems recognize presentations with limited switching or co‑consciousness rather than full executive takeover by alters [7] [8]. The WHO emphasized global applicability and clinical utility in shaping ICD‑11, which partly motivated creating a pDID label to reduce reliance on unspecified diagnoses and to reflect observed clinical heterogeneity [5] [1]. Empirically, measures developed for ICD‑11 (e.g., the IDIDQ) show promise in identifying both DID and pDID cross‑culturally, supporting the utility of the two‑tier distinction [10].
5. Interpretive cautions and competing viewpoints
Debate continues: some clinicians welcome pDID for reducing “not otherwise specified” noise and for aligning diagnoses with observed dominance/co‑conscious patterns, while others worry that diverging manuals complicate research comparability and insurance coding, or that label proliferation risks pathologizing stress‑linked dissociative reactions [5] [3]. Additionally, the ICD‑11’s choice not to require amnesia reflects a pragmatic, global‑utility stance from WHO working groups rather than definitive evidence that amnesia is non‑essential in all contexts; DSM‑5’s retention of amnesia prioritizes a stricter phenomenological gate for DID [2] [5]. Reporting and measurement studies suggest the two systems are reconcilable if clinicians document which criteria subsets are present, but cross‑manual translation remains an ongoing research and practice challenge [10] [1].