DISSOCIATIVE AMNESIA Homayoun Amini M.D. Assis. Prof. of Psychiatry Roozbeh Hospital TUMS

INTRODUCTION Two main elements of dissociation : 1- they lack evidence of proximate organic illness or pathophysiological disturbance; 2 – the symptoms correspond to ideas of the patient about how parts of the body or mind malfunction or fail to function;

DEFINITION Dissociative phenomena are limited to amnesia Key symptoms is the inability to recall information, usually about stressfull or traumatic events in person’s lives There may be a loss of knowledge of personal identity with preservation of other information, often including complex learned information or skills

DEFINITION It cannot be explained by ordinary forgetfulness There is no evidence of an underlying brain disorder Persons retain the capacity to learn new information

SUBTYPES Localized: a circumscribed period of time Selective: some, but not all, of the events during a circumscribed period of time Generalized: the person’s entire life Continuous: events subsequent to a specific time up to and including present Systematized: certain categories of information

EPIDEMIOLOGY Amnesia is the most common dissociative symptoms More often in women than in men More often in young adults than in older adults Incidence increases during times of war & natural disasters

EPIDEMIOLOGY In civilian cases, a history of head trauma or brain damage is often present The condition may be more frequent amongst criminals or soldiers in distress Tends to present to accident & emergency departments and then to neurologists, but is only seen secondarily in psychiatric departments

ETIOLOGY Psychoanalytic approach: emotional conflict, primary & secondary gain Hx of child abuse ?? Amnesia seems to be related to immediate adult adjustment problems, rather than the consequences of early child abuse The theory of state-dependent learning

DIAGNOSIS (DSM-IV-TR) A. The predominant disturbance is one or more episode of inability to recall important personal information, usually of a traumatic or stressful nature, that is too extensive to be explained by ordinary forgetfulness. B. The disturbance does not occur exclusively during the course of dissociative identity disorder, dissociative fugue, PTSD, ASD, or somatization disorder, and is not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a neurological or other GMC (e.g., amnestic disorder due to head trauma). C. The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.

DIAGNOSIS (ICD-10) G1. There must be no evidence of a physical disorder that can explain the characteristic symptoms of this disorder (although physical disorders may be present that give rise to other symptoms). G2. There are convincing associations in time between the onset of symptoms of the disorder and stressful events, problems, or needs. G3. There must be amnesia, either partial or complete, for recent events or problems that were or still are traumatic or stressful. G4. The amnesia is too extensive and persistent to be explained by ordinary forgetfulness (although its depth and extent may vary from one assessment to the next) or by intentional simulation.

CLINICAL FEATURES Onset is often abrupt Patients are usually aware that they have lost their memories Some patients are upset but others appear to be unconcerned Amnestic patients are usually alert before and after the amnesia occurs Depression and anxiety are common predisposing factors Distortions in time perception

DIFFERENTIAL DIAGNOSIS Clinicians should conduct: - a medical history - a physical examination - a psychiatric history - a MSE - a laboratory workup

DIFFERENTIAL DIAGNOSIS… Is the amnesia a result of an organic disease? a psychiatric disorder? a dissociative disorder?

DIFFERENTIAL DIAGNOSIS… Amnestic disorders: - epileptic seizures: short duration, less identity confusion, stereotypic -head injury: brief retrograde amnesia + longer anterograde amnes - korsakoff’s syndrome: significant anterograde amnesia + variable rerograde amnesia, intact other cognitive functions

DIFFERENTIAL DIAGNOSIS… Transient Global Amnesia: - Acute - Transient(prompt return of memory) - Recent memory is often impaired - Highly complex mental & physical acts are preserved

DIFFERENTIAL DIAGNOSIS… TGA can be differentiated from dissociative amnesia: - anterograde amnesia - more upset and concerned - personal identity is retained - more generalized - most common in 60s & 70s

DIFFERENTIAL DIAGNOSIS… Dementia: multiple cognitive deficits, Delirium: altered consciousness, impaired attention, fluctuation, Cerebral infections & neoplasms Metabolic disorders ….

DIFFERENTIAL DIAGNOSIS… Organic amnesias have several distinguishing features: - no recurrent identity alteration - not selectively limited to personal information - do not focus on or result from an emotionallt traumatic event - more often anterograde than retrograde

DIFFERENTIAL DIAGNOSIS… Organic amnesias have several distinguishing features…. - usually permanent (excluding substance abuse, TGA, metabolic, delirium,…) - the erasure or destruction of memory or not registration

DIFFERENTIAL DIAGNOSIS… Substance use disorders: - alcohol - sedative hypnotics - anticholinergics - steroids - lithium carbonate - beta blockers - hypoglycemic agents - marijuana - hallucinogens - pentazocine - phencyclidine

DIFFERENTIAL DIAGNOSIS… Psychiatric disorders: - depression - PTSD - acute stress disorder - somatoform disorders - sleep disorders - factitious disorder - malingering Other dissociative disorders: - fugue - identity

COURSE & PROGNOSIS Recovery is usually complete and termination may be rapid in localized or selective subtypes Recovery is usually gradual in generalized subtype Functional impairment varies from mild to severe, depending on the extent of the amnesia The more acute & the more recent the instance of dissociative amnesia, the more likely & the more quickly it is to be resolved

TREATMENT Intrusive attempts to retrieve memories can result in retraumatization if the patient is not properly prepared This risk is especially great for longstanding or childhood-onset amnesias The clinician should control the pace of suggested recollection, usually within the framework of a broader psychotherapy In extreme cases, hospitalization may be necessary

TREATMENT… Group psychotherapy: especially successful in helping combat veterans and survivors of childhood abuse Hypnosis Drug-assisted interview