TRAUMATIC AMNESIAS: psychogenic forgetting?

• Global retrograde amnesias and fugues– Sudden loss of autobiographical memory and

identity– May be triggered by severe psychological stress– Some evidence for link to earlier physical trauma

or disease– Pattern of recovery is diverse

• Sudden, quick and complete• Gradual and incomplete• Failure of recovery

– Rarer than the media suggest• < 1% of clinical casework in some estimates

Renee ZellwegerAs Nurse Betty

Richard Gere and EdNorton in Primal Fear

"A fugue is a combination of amnesia and physical fright. The individual flees from his customary surroundings toward the assumptions of a new identity.“

American Psychiatric Association 1994 Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition

• Recovery from Fugue states: a sampler– Libby Morris: lost from a shopping mall

• Rapid, almost complete recovery• Amnesia for fugue period

– Ricky Stephenson: AWOL• Unresolved after two years• Relearning his past

– Jody Roberts: You’re a thousand miles away• Unresolved after 12 years• New, stable identity established

– James Smith: Rip vanWinkle awakes• Fugue ends after 25 years• “gap” before recovery• Amnesia for fugue period

• Dissociative Identity Disorder (aka Multiple Personality Disorder): A capsule history– Rash of cases in late 19th century

• Seen as symptom of “hysteria”– Extremely rare until 1980’s

• Pre 1970’s < 100; ’85 – ’89, c. 40,000• Media and professional attention

– DID and the recovered memory movement• Often linked to recovered memories of

abuse, other more bizarre experiences• Often evolves during aggressive

therapy– 1990’s: backlash of skepticism

Recanters in court

CHARACTERISTICS OF DID

• The person– Associated with early, chronic abuse or

trauma (est. 50-70% sexual or physical abuse incidence)

– And with “a trail of psychopathology”– Tend to be highly hypnotizable

• Memory aspects– Autobiographical dissociation may be

complete, or “leaky”– Some evidence for implicit memory

“across identities”• The outlook

– May resolve with therapy or time– Difficult to separate “genuine” cases

from role-playing– Relation to everyday “dissociations” in

mood and memory– Relation to fugues?

DID: an fMRI study(Tsai, et al. 1999)

• 47-yr old woman– Severe childhood abuse– DID and PTSD diagnosis; long-term

therapy– Hippocampal volume reduced

1.1 cm3 vs. 2.6 +/-.02 cm3

– Normal-range score (106) on WMS• Cued switch to/from:

– Alter personality (“Guardian” 8 yr old)– Irrelevant personality (“Player” 8 yr old)

• Avg. 30 seconds to switch– fMRI during switch, maintenance– Right hippocampus:

• Inhibition during switch to alter• Activation during switch from alter• No changes during “control” switches