Multiple personality syndrome

Dissociative identity disorder
An artist's interpretation of one person with multiple "dissociated personality states"
Classification and external resources
Specialty	Psychiatry
ICD-10	F44.8
ICD-9-CM	300.14
DiseasesDB	Comorbid
eMedicine	article/916186
MeSH	D009105
[]

Dissociative identity disorder (DID), also known as multiple personality disorder (MPD), is a mental disorder characterized by at least two distinct and relatively enduring identities or dissociated personality states. These states alternately show in a person's behavior, accompanied by memory impairment for important information not explained by ordinary forgetfulness. These symptoms are not accounted for by substance abuse, seizures, or other medical conditions, nor by imaginative play in children. Dissociative symptoms range from common lapses in attention, becoming distracted by something else, and daydreaming, to pathological dissociative disorders. Symptoms vary over time.

Dissociative disorders, including DID, have been attributed to disruptions in memory caused by trauma or other forms of stress. Research on this hypothesis has been characterized by poor methodology. An alternative hypothesis is that DID is a by-product of techniques employed by some therapists, especially those using hypnosis, and disagreement between the two positions is characterized by intense debate. DID is one of the most controversial psychiatric disorders, with no clear consensus on diagnostic criteria or treatment. No systematic, empirically supported definition of "dissociation" exists. Diagnosis is often difficult, as the illness is frequently associated with other mental disorders. Differential diagnosis should consider malingering if the individual's principal concern is with financial or forensic gain or with the avoidance of obligations; and factitious disorder, if the individual's principal concern is with assuming a patient role.

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