DDx DID vs Bipolar esp Bipolar II

The topic of this thread is the differential diagnosis (DDx) of dissociative identity disorder vs bipolar disorder especially rapid cycling bipolar II.

Per DSM-5 the differential diagnosis of DID includes: other specified dissociative disorder (OSDD); major depressive disorder (MDD); bipolar disorders; post-traumatic stress disorder (PTSD); psychotic disorders including schizophrenia; substance and medication-induced disorders; personality disorders, especially borderline personality disorder; conversion disorder (functional neurological symptom disorder); seizure disorder; factitious disorder and malingering. DSM-5 also notes diagnostic issues relating to sex (gender) and culture. Wow, this DDx can be a lot of work!

To assist in diagnosing DID amid all these other possibilities, numerous pen-and-paper interview schedules and other tools have been developed. Diagnosis of DID does not involve exploring trauma. Two screening tools often are used together: Dissociative Experiences Scale (DES) and Somatoform Dissociation Questionnaire (SDQ). Both DES and SDQ are available on the web, in many languages. Here are two sources:

DES: http://traumadissociation.com/des
SDQ: http://www.enijenhuis.nl/sdq/

There is not much written specifically about the differential diagnosis of DID vs bipolar. Here are a few related DID Forum threads and a blog:

• DID Forum, 2011: Differential diagnosis - discussion of diagnostic intruments DDIS, MID, and DID vs bipolar
• DID Forum, 2013: Bipolar Disorder and DID - discussion of comorbidity vs mis-diagnosis
• DID Forum, 2017: DID vs bipolar - non-technical questions about differential diagnosis of DID vs bipolar
• Dissociative Living: the differences between bipolar disorder and DID - personal blog by Crystalie Matulewicz, diagnosed bipolar II and treated with (ineffective) medication for 14 years before being diagnosed DID

Many public libraries have DSM-5, but in a reference collection not on open shelves; check the catalog or ask at the reference desk.