Substance/medication-induced disorders. Symptoms associated with the physiological effects of a substance can be distinguished from dissociative identity disorder if the sub- stance in question is judged to be etiologically related to the disturbance.
Personality disorders. Individuals with dissociative identity disorder often present identi- ties that appear to encapsulate a variety of severe personality disorder feahires, suggesting a differential diagnosis of personality disorder, especially of the borderline type. Importantly, however, the individual’s longitudinal variability in personality style (due to inconsistency among identities) differs from the pervasive and persistent dysfimction in affect management and interpersonal relationships typical of those with personality disorders.
Conversion disorder (functional neurological symptom disorder). This disorder may be distinguished from dissociative identity disorder by the absence of an identity disruption characterized by two or more distinct personality states or an experience of possession.
Dissociative amnesia in conversion disorder is more limited and circumscribed (e.g., am- nesia for a non-epileptic seizure).
Seizure disorders. Individuals with dissociative identity disorder may present with sei- zurelike symptoms and behaviors that resemble complex partial seizures with temporal lobe foci. These include déja vu, jamais vu, depersonalization, derealization, out—of—body experiences, amnesia, disruptions of consciousness, hallucinations, and other intrusion phenomena of sensation, affect, and thought. Normal electroencephalographic findings, including telemetry, differentiate non—epileptic seizures from the seizurelike symptoms of dissociative identity disorder. Also, individuals with dissociative identity disorder obtain very high dissociation scores, whereas individuals with complex partial seizures do not.
Factitious disorder and malingering. Individuals who feign dissociative identity disor- der do not report the subtle symptoms of intrusion characteristic of the disorder; instead they tend to overreport well-publicized symptoms of the disorder, such as dissociative amnesia, while underreporting less-publicized comorbid symptoms, such as depression.
Individuals who feign dissociative identity disorder tend to be relatively undisturbed by or may even seem to enjoy ”having” the disorder. In contrast, individuals with genuine dissociative identity disorder tend to be ashamed of and overwhelmed by their symptoms and to underreport their symptoms or deny their condition. Sequential observation, cor- roborating history, and intensive psychometric and psychological assessment may be helpful in assessment.
Individuals who malinger dissociative identity disorder usually create limited, stereo- typed alternate identities, with feigned amnesia, related to the events for which gain is sought. For example, they may present an ”all-good” identity and an "all-bad” identity in hopes of gaining exculpation for a crime.
Many individuals with dissociative identity disorder present with a comorbid disorder. If not assessed and treated specifically for the dissociative disorder, these individuals often receive prolonged treatment for the comorbid diagnosis only, with limited overall treat- ment response and resultant demoralization, and disability.
Individuals with dissociative identity disorder usually exhibit a large number of co- morbid disorders. In particular, most develop PTSD. Other disorders that are highly co- morbid with dissociative identity disorder include depressive disorders, trauma- and stressor-related disorders, personality disorders (especially avoidant and borderline per- sonality disorders), conversion disorder (functional neurological symptom disorder), somatic symptom disorder, eating disorders, substance-related disorders, obsessive- compulsive disorder, and sleep disorders. Dissociative alterations in identity, memory, and consciousness may affect the symptom presentation of comorbid disorders.
Diagnostic Criteria 300.12 (F44.0)
A. An inability to recall important autobiographical information, usually of a traumatic or stressful nature, that is inconsistent with ordinary forgetting.