6.1 Dissociative Disorders and 6.2 Dissociative Amnesia

Question 1

What is a ‘dissociation’?

Answer 1

Dissociation is defined as either a:

1. Loss of memory
2. Loss of identity
3. Loss of sense of self
4. Discontinuity with consciousness

Question 2

What is the ‘self’, according to a psychiatric definition?

Answer 2

The ‘self’ is a unique identity, comprised of the individual’s thoughts, behaviours, feelings and memory.

Question 3

What are the 4 common manifestations of dissociative disorders?

Answer 3

1. Dissociative amnesia
2. Dissociative fugue (a sub-type of dissociative amnesia)
3. Dissociative identity disorder
4. Depersonalisation/derealisation

Question 4

Describe the general aetiology of all dissociative disorders.

Answer 4

1. Dissociative disorders are primary disorders, unlike amnestic disorders, which have an underlying medical condition or substance abuse.
2. Dissociative disorders are known to be associated with:
   
   • Childhood abuse
   • Acute adult trauma
   • Substance abuse
   • Major mood disorders

Question 5

What is dissociative amnesia?

Answer 5

1. Potentially reversible memory impairment.
2. Not able to be explained by ordinary forgetfulness.
3. Affects autobiographical information.
4. Awareness of having trouble remembering.
5. Not bothered by having trouble remembering.

Question 6

Describe the 4 types of memory from a psychiatric perspective.

Answer 6

1. Autobiographical memory
2. Semantic memory
3. Procedural memory
4. Episodic memory

Question 7

Describe the epidemiology of dissociative amnesia.

Answer 7

1. The most common dissociative disorder.
2. Prevalence is 10%.
3. Increased incidence of comorbid major depression and anxiety disorders.
4. Females are more often affected than males.
5. Younger adults affected more than older adults.

Question 8

Describe the aetiology of dissociative amnesia.

Answer 8

Epigenetic Model

Environmental trauma, combined with genetic factors trigger a genetic diathesis for dissociative amnesia.

Temporal, hippocampal, occipital areas associated with autobiographical memory are affected at a neurobiological level.

Question 9

Describe the 4 diagnostic criteria which need to be met to diagnose someone with potential dissociative amnesia.

Answer 9

1. An inability to recall important autobiographical information that is inconsistent with ordinary forgetfulness.
2. Symptoms cause distress or impairment in social, occupational, or other functioning.
3. Disturbance is not due to effects of substance, neurological or general medical condition.
4. Disturbance is not better explained by another psychiatric disorder. Also specify if associated with dissociative fugue.

Question 10

Name 2 features which differ in the memory loss caused by dementia versus that caused by dissociative amnesia.

Answer 10

In dementia, unlike in dissociative amnesia, patients are:

1. Upset by memory loss.
2. Trying to recall memories.

Question 11

List 7 other common differentials which should be ruled out before diagnosing dissociative amnesia?

Answer 11

1. Alcohol abuse or substance induced
2. Depression
3. Anxiety
4. Factitious disorders
5. Malingering
6. Ganser syndrome
7. Other disorders, e.g. dissociative identity disorder, psychotic disorders, cognitive disorders, personality disorder.

Question 12

What is Ganser Syndrome?

Answer 12

Ganser syndrome is a reaction to severe stress, patient suffers from approximations or giving absurd answers to simple questions.

Useful abstract:

https://www.karger.com/Article/PDF/475676

Question 13

Name 10 features of the perpetrated trauma that increase the risk of a dissociative disorder.

Answer 13

1. Human assault rather than natural disaster.
2. Repeated traumatisation (as opposed to a single event).
3. Longer duration of trauma.
4. Fear of death or significant harm during trauma.
5. Trauma caused by multiple perpetrators.
6. Close relationship between perpetrator and victim.
7. Betrayal by caretaker as part of abuse.
8. Threats of death or significant harm by the perpetrator if the victim discloses.
9. Violence of trauma leading to physical injury.
10. Earlier age of onset of the trauma.

Question 14

Describe the types of dissociative amnesia you may see in a psychiatric setting.

Answer 14

Scope of Amnesia

1. Generalized amnesia: the person has trouble remembering the details of their entire life.
2. Localized amnesia: the person has trouble remembering the details of a specific time period, e.g., an assault.
3. Selective amnesia: patchy or incomplete recollection of a particular event.
4. Systematized amnesia: very specific memory loss, e.g., forgetting a particular relative.

Presentation of Amnesia

1. Type 1 - Overt dissociative amnesia, very obvious, dramatic, profound loss of memory, personal history and personal identity.
2. Type 2 - Covert dissociative amnesia, more common, not uncovered unless the clinician probes for it.

Useful link: https://abbotsfordprivate.com.au/specialties/trauma-and-dissociation/about-trauma-and-dissociative-disorders