Dissociative identity disorder and partial dissociative identity disorder

BACKGROUND: The diagnosis dissociative identity disorder (DID) replaces multiple personality disorder in the ICD-11. It is characterized by the presence of two or more distinct personality states (dissociative identities) and, typically, by amnesia from one state to another. The personality states are associated with marked discontinuities in the experience of self and in the ability to take charge of one's own actions. In partial DID, the discontinuities are less marked. In this review, we summarize and discuss empirical studies on DID and partial DID and derive potential approaches to this problem in clinical practice. METHODS: This narrative review is based on pertinent publications retrieved by a PubMed search. RESULTS: Only a small number of empirical studies on DID are available, and most suffer from major methodological limitations. Robust data for partial DIS are entirely lacking. The extant findings reveal a marked overlap between DID and other trauma-associated disorders, especially complex post-traumatic stress disorder (cPTSD) and borderline personality disorder (BPD). The available data tend not to support central constructs of DID; in particular, they do not support the postulated amnesia between the personality states. There is no robust evidence for the efficacy of any specific treatment. CONCLUSION: DID and partial DID are insufficiently validated diagnoses for which there is no evidence-based treatment. Dissociative symptoms are already covered by better-researched entities, including cPTSD and BPD, for which validated treatment options are available. The diagnoses of DID and partial DID should only be assigned if alternative explanations of the patient's clinical manifestations have been excluded.