January 02, 2011

Multiple Personalities

Dissociative Identity Disorder (DID) is pretty much the most fascinating DSM diagnosis of all. Formerly called Multiple Personality Disorder, DID is a rare disorder diagnosed when a client presents more than one discrete identity or personality state that recurrently takes control of his or her behaviour. Each identity has a distinct and enduring way of behaving, perceiving, and interacting. Correspondingly, in addition to significant memory lapses and time unaccounted for, symptoms of DID include things like being told that one behaved extremely uncharacteristically, not responding to one's name, and being frequently accused of lying.

DID is associated with early traumatic experiences, particularly childhood physical or sexual abuse, often by a parent or other trusted caregiver. The hypothesis is that dissociation is an extreme response to severe trauma: the mind splits off the memory and awareness of the abuse; the memories go into the subconscious and eventually emerge in another personality, meanwhile allowing the original identity to exist as though untraumatized. 

Without forgetting the anguish and suffering inherent to DID, I can't help but be impressed by the brain's capacity to protect individuals from their own terrible experiences by creating a separate personality to whom the terrible experiences happened. Some research has even found evidence for differences between identities in handwriting, and in physiological variables like heart rate and blood pressure! 

Clinical psychology doesn't get more amazing than that. 


  1. While I can't speak to the accuracy of its portrayal of DID, "The United Sates of Tara" is a pretty good TV drama on the subject.

  2. Is DID common in serial killers or is the "Norman Bates" syndrome strictly a product of Hollywood?

  3. Jess - didn't know about TUSoT but am going to download it ASAP.

    Anonymous - I don't think DID per se is necessarily characteristic of serial killers, but I'm willing to hazard that most extreme deviants (serial killers and the like) have a history of trauma and abuse, provoking dissociation or not.

  4. Thanks for the clarification! I don't know why the post acme out as 'Anonymous'. Must have clicked the wrong thingie.


  5. Sarah - just to add to the "different handwriting", I've also heard of people's bodies being physically different! Wasn't there a case where a tumor was found in a patient's brain, and then when the other personality emerged, the tumor was gone?