Borderline and other personality disorders may be a secondary diagnosis describing the underlying characterological functioning of a patient who exhibits more acute and prominent symptoms of a state disorder. Several studies show a high prevalence of BPD in patients with Dissociative Identity Disorder may be even as high as 82%! Dissociation is a common experience for people with borderline personality disorder (BPD).
Do you sometimes feel as if you have "zoned out?" Do you have times when you feel "unreal" or when things around you look strange or unfamiliar? Do you sometimes lose periods of time or have chunks of the day that you do not remember? Do these experiences usually happen when you are under a lot of stress? These are all forms of dissociation which can range from mild and transitory to severe and chronic.
While dissociation is also a symptom of borderline personality disorder, usually the dissociation seen in BPD does not happen as frequently or as severely as in DID (i.e. other personalities do not emerge). Someone with the symptoms of DID and BPD may receive a diagnosis of both disorders. You may also be similar to me- My primary diagnosis is DID, but one of my alter personalities has BPD, so BPD is my secondary diagnosis. How is this possible? In people diagnosed with DID, individual alters may harbor knowledge, talents, or illnesses otherwise unknown to the original personality or other alters as well as different memories. In the case of Sybil, one of her alters knew how to play the piano while the others could not. In another case I read about in a book called ‘Am I a Good Girl Yet?’ One of the author’s alters had significant visual impairment requiring glasses and the others did not. One of my alters only speaks the Indonesian language.