6.4 Dissociative Identity Disorder

Question 1

What is dissociative identity disorder?

Answer 1

1. It is a controversial diagnosis. Formerly known as multiple personality disorder and can also mimic borderline personality disorder.
2. Two or more distinct personalities that alternately control behaviours and thoughts.
3. While one personality is dominant, that personality is usually (but not always) unaware of events that occur during prior personality states.
4. There are alterations in affect, behaviour, consciousness, perception, cognition and or sensory-motor functioning.

Question 2

What is the epidemiology of dissociative identity disorder?

Answer 2

Very rare disorder.

• >90% are women
• 1% prevalence amongst those already in mental health care
• Most patients experience a prior trauma, especially child sexual or physical abuse
• Average age of diagnosis is 30 years old
• High co-morbidity with depression, anxiety disorders, BPD, substance abuse.
• 1/3 patients attempt suicide

Question 3

Name 5 additional mental health diagnoses which are usually co-morbid with dissociative identity disorder.

Answer 3

1. PTSD
2. Depression
3. Substance abuse
4. Somatoform conditions, e.g., headache, non-epileptic seizures, conversion disorder, somatoform disorder.
5. Personality disorder, e.g., borderline personality and avoidant.

Question 4

Describe the 2 models used to describe the development of dissociative identity disorder.

Answer 4

1. Trauma Model:
   
   • Predisposing factors including dissociativity (i.e., a tendency to dissociate)
   • Dissociation is a response to trauma, often thought to be early childhood abuse.
2. Sociocognitive Model:
   
   • Patients learn to construe themselves as multiple selves.
   • DID symptoms are believed to be absorbed by patients through representations in books, media, etc.

Question 5

Can name 5 dissociative symptoms?

Answer 5

1. Amnesia
2. Depersonalisation
3. Derealisation
4. Trance state
5. Self-alteration

Question 6

Describe the diagnostic criteria which must be met in order for dissociative identity disorder to be diagnosed.

Answer 6

1. Presence of one or more personality states.
2. Recurrent gaps in recall of everyday events, important personal information, and or/ traumatic events that are inconsistent with ordinary forgetting.
3. Clinically significant distress or impairment in social or occupational functioning.
4. Disturbance is not part of a cultural or religious practice.
5. Not due to substances or a general medical condition.

Question 7

List 8 differential diagnoses for dissociative identity disorder.

Answer 7

1. Intoxication - cannabis, hallucinogens, ketamine, ecstasy.
2. General medical conditions - dementia, seizures.
3. PTSD - re-experiencing, avoidance, numbing, hyperarousal.
4. BPD - cutting, splitting, self-harm, chronic feelings of emptiness, outbursts, inability to sustain relationships.
5. Schizophrenia - hallucinations, delusions, disorganized thoughts, speech and behaviour.
6. Bipolar disorder - Mania, hypomania and depression.
7. Factitious disorder - Feigning symptoms for primary gain.
8. Malingering - Feigning symptoms for secondary gain.

Question 8

How to treat dissociative identity disorder?

Answer 8

• Usually chronic with incomplete recovery.
• Patients with earlier age of onset have a poorer prognosis.

Treatment is with the following:

1. Hypnosis, drug-assisted interviewing, insight-oriented psychotherapy.
2. Pharmacotherapy as needed if co-morbidity develops, e.g., depression - SSRI’s.