Dissociative Disorders

1. Clinical Overview

Summary

Dissociative disorders are a group of psychiatric conditions characterised by disruption in the normal integration of consciousness, memory, identity, emotion, perception, body representation, motor control, and behaviour. [1] The core pathological feature is dissociation—a disconnection between thoughts, memories, feelings, actions, or sense of identity—that serves as a psychological defence mechanism against overwhelming trauma. [2]

These disorders exist on a spectrum from transient dissociative symptoms experienced by many individuals to severe, chronic conditions such as Dissociative Identity Disorder (DID). The DSM-5 recognises four main dissociative disorders: Dissociative Identity Disorder (DID), Dissociative Amnesia (with or without fugue), Depersonalisation/Derealisation Disorder, and Other Specified Dissociative Disorder. [3]

The aetiology is strongly linked to severe, repeated psychological trauma, particularly interpersonal violence and childhood abuse occurring before age 9, during critical periods of personality development. [4] Dissociation represents a failure of integration of traumatic experiences into the autobiographical narrative, leading to compartmentalisation of traumatic memories, emotions, and identity states. [5]

Treatment is primarily psychotherapeutic, following a phase-oriented approach: stabilisation and symptom reduction, trauma processing, and integration/rehabilitation. [6] Evidence supports trauma-focused cognitive behavioural therapy (TF-CBT), Eye Movement Desensitisation and Reprocessing (EMDR), and dialectical behaviour therapy (DBT) approaches. [7] Pharmacotherapy has limited direct efficacy for dissociative symptoms but may address comorbid conditions such as depression and PTSD. [8]

Key Facts

Epidemiology:

• General population prevalence: 1-3% for dissociative disorders overall [1]
• DID prevalence: 1-1.5% in community samples, 5-10% in psychiatric inpatients [9]
• Depersonalisation/derealisation disorder: 0.8-2.8% [10]
• Female predominance (F:M = 3-9:1 for DID) [11]

Aetiology:

• 90% of DID cases report childhood trauma (physical, sexual, or emotional abuse) [12]
• Age of onset of trauma: typically before age 9 during identity formation [4]
• Disorganised attachment is a significant risk factor [13]

Clinical Features:

• DID: Two or more distinct personality states with amnesia between states
• Dissociative amnesia: Inability to recall important autobiographical information
• Depersonalisation: Feeling detached from oneself (observing from outside)
• Derealisation: Feeling the external world is unreal or dreamlike

Differential Diagnosis:

• PTSD and complex PTSD (overlapping features)
• Borderline personality disorder (identity disturbance)
• Psychotic disorders (auditory hallucinations vs internal voices)
• Temporal lobe epilepsy (transient dissociative states)
• Substance-induced dissociation
• Malingering and factitious disorder

Management:

• Phase-oriented trauma psychotherapy (stabilisation → processing → integration)
• Trauma-focused CBT and EMDR [7,14]
• Grounding techniques for acute dissociation
• SSRIs for comorbid depression/anxiety (limited evidence for dissociation itself) [8]

Clinical Pearls

"Dissociation is a Defence Mechanism": Dissociation develops as an adaptive response to overwhelming trauma when physical escape is impossible. Understanding this reframes symptoms as survival mechanisms rather than pathology. [2]

"Screen Sensitively for Trauma History": Dissociative disorders are among the most trauma-associated psychiatric conditions. A trauma-informed approach is essential—ask about adverse childhood experiences systematically but sensitively. [15]

"Grounding is the First-Line Intervention": When patients present with acute dissociation, grounding techniques (5-4-3-2-1 sensory awareness, cold water, strong scents) are more effective than benzodiazepines, which may worsen dissociation. [16]

"Internal Voices in DID are NOT Psychotic": Patients with DID often hear internal voices representing different identity states. Unlike schizophrenia, these voices are recognised as internal, there is typically no formal thought disorder, and antipsychotics are ineffective. [17]

"Rule Out Organic Causes First": Always exclude temporal lobe epilepsy (EEG), substance use (drug screen), and neurological conditions (MRI if indicated) before diagnosing primary dissociative disorder. [3]

"Integration is NOT Always the Goal": In DID, the treatment goal is not necessarily fusion of personality states. Many patients achieve excellent functioning with cooperative coexistence of identity states ("integration without fusion"). [6]

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2. Epidemiology

Prevalence

General Population:

• Dissociative disorders overall: 1-3% in community samples [1]
• Dissociative Identity Disorder (DID): 1-1.5% [9]
• Depersonalisation/Derealisation Disorder: 0.8-2.8% [10]
• Dissociative amnesia: 1.8% [18]

Clinical Populations:

• Psychiatric inpatients: 5-10% meet criteria for DID [9]
• Outpatient psychiatric settings: 5-12% have a dissociative disorder [1]
• Trauma-exposed populations: Up to 30% experience dissociative symptoms [15]

Transient Dissociative Experiences:

• Mild dissociative experiences (e.g., highway hypnosis, daydreaming): 60-70% of general population [2]
• Peritraumatic dissociation during trauma: 20-40% [5]

Demographics

Risk Factors

Protective Factors

• Secure attachment relationships
• Early intervention after trauma
• Strong social support network
• Access to mental health care
• Resilience and adaptive coping strategies

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3. Aetiology and Pathophysiology

Trauma-Dissociation Model

The Trauma Model of Structural Dissociation is the predominant aetiological framework: [5]

1. Overwhelming Trauma Exposure: Child experiences severe, repeated trauma (sexual abuse, physical violence, emotional neglect)
2. Developmental Context: Occurs during critical periods of identity formation (typically ages 5-9) when integrative capacities are immature
3. Dissociation as Defence: When physical escape is impossible, the child psychologically "escapes" through dissociation—detaching from the traumatic experience
4. Failure of Integration: Traumatic memories, emotions, and sensory experiences are not integrated into the coherent autobiographical narrative
5. Structural Dissociation: Personality becomes divided into separate systems:
   • Apparently Normal Part (ANP): Functions in daily life, avoids trauma reminders
   • Emotional Part (EP): Holds traumatic memories and defensive reactions
6. Chronic Compartmentalisation: In severe cases (DID), multiple distinct identity states develop, each with own memories, behaviours, and sense of self

Neurobiological Mechanisms

Exam Detail: Neuroimaging Findings:

Structural Changes: [5,11]

• Hippocampal volume reduction: Smaller hippocampi (memory consolidation centre), similar to PTSD
• Amygdala hyperactivation: Increased amygdala reactivity to trauma cues
• Prefrontal cortex: Reduced volume and function in orbitofrontal and medial prefrontal cortex (emotional regulation)
• Corpus callosum: Reduced volume, suggesting impaired interhemispheric communication

Functional Changes:

• Decreased connectivity between prefrontal cortex and limbic regions (poor top-down control of emotion)
• State-dependent activation: Different brain activation patterns in different identity states in DID [11]
• Altered DMN (Default Mode Network): Abnormal connectivity in self-referential processing network [10]

HPA Axis Dysregulation: [15]

• Chronic stress leads to HPA axis dysfunction
• Blunted cortisol responses to stress
• Similar neuroendocrine profile to chronic PTSD

Neurotransmitter Systems:

• Glutamate/NMDA: Peritraumatic dissociation may involve NMDA receptor antagonism
• Serotonin: Dysregulation implicated in mood and anxiety comorbidities
• Endogenous opioids: May mediate emotional numbing and analgesia during dissociation

Psychological Mechanisms

Cognitive Models:

• Compartmentalisation: Segregation of memories, emotions, and identity to avoid overwhelming affect
• Detachment: Emotional numbing and sense of unreality as protective mechanism
• Altered sense of self: Identity fragmentation in severe cases

Attachment Theory: [13]

• Disorganised attachment (fearful caregiver who is also source of comfort) creates irresolvable paradox
• Child cannot integrate contradictory representations of caregiver
• Dissociation allows simultaneous holding of incompatible mental states

Social-Cognitive Model:

• Dissociation represents failure of source monitoring (distinguishing internal vs external information)
• Impaired autonoetic consciousness (sense of self across time)

Genetic and Biological Factors

• Heritability: Moderate genetic contribution (30-50%) to dissociative tendencies [2]
• Gene-environment interaction: Genetic vulnerability + environmental trauma
• No single "dissociation gene": Likely polygenic with overlap with PTSD genetics

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4. Clinical Presentation

Dissociative Identity Disorder (DID)

Formerly "Multiple Personality Disorder"

DSM-5 Diagnostic Criteria: [3]

Clinical Features:

Identity States ("Alters"):

• Distinct names, ages, genders, or personality characteristics
• Different behavioural patterns, preferences, handwriting
• Different memories and amnesia for what other alters do
• Typically 2-15 alters (median ~10) [4]
• Common types: child alters, protector alters, persecutor alters, host alter

Switching:

• Transition from one identity state to another
• May be triggered by stress, trauma reminders, or spontaneous
• Observable changes: posture, voice, facial expression, language
• Can be accompanied by dissociative amnesia

Amnesia Patterns:

• "Losing time" (hours or days unaccounted for)
• Finding evidence of actions with no memory (purchases, writings)
• Being told of behaviours they don't recall
• Fluctuating knowledge and skills

Internal Voices:

• Hearing different alters conversing or arguing
• Experienced as internal (not external like schizophrenia)
• May be distressing (persecutory alters) or helpful (protector alters)

Other Features:

• Flashbacks and intrusive trauma memories
• Chronic depersonalisation and derealisation
• Self-harm (often by persecutor alters)
• Passive influence phenomena (feeling controlled by another part)

Dissociative Amnesia

DSM-5 Diagnostic Criteria: [3]

Subtypes:

Dissociative Fugue:

• Subtype: sudden, unexpected travel away from home
• Amnesia for past, sometimes confusion about identity
• Usually brief (hours to days), ends abruptly
• Upon recovery, amnesia for fugue period

Clinical Features:

• Usually follows traumatic event (assault, combat, disaster)
• Amnesia is reversible (unlike organic amnesia)
• Patient is distressed by memory gaps
• No impairment of new learning (unlike dementia)
• Normal neurological examination

Depersonalisation/Derealisation Disorder

DSM-5 Diagnostic Criteria: [3]

Clinical Features:

Depersonalisation:

• Feeling like an outside observer of own thoughts, body, actions
• Emotional numbing (recognising emotions intellectually but not feeling them)
• Feeling like an automaton or robot
• Out-of-body experiences
• Subjective sense of time distortion

Derealisation:

• Surroundings seem unreal, dreamlike, foggy, lifeless
• Visual distortions (objects seem larger/smaller, colours muted)
• Feeling separated from surroundings by invisible barrier (like looking through glass)
• Auditory distortions (voices sound distant, muffled)

Associated Features:

• Chronic anxiety about depersonalisation ("Am I going crazy?")
• Checking behaviours (looking in mirror, pinching self)
• Difficulty describing experiences ("hard to put into words")
• Often comorbid with anxiety disorders, depression, PTSD

Other Specified Dissociative Disorder

Includes presentations with dissociative symptoms that cause distress/impairment but don't meet full criteria, such as:

• Chronic dissociative symptoms after prolonged coercive persuasion
• Acute dissociative reactions to stressful events (duration less than 1 month)
• Dissociative trance (involuntary, not culturally accepted)

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5. Clinical Examination

Mental State Examination

Observing Dissociation During Interview

Acute Dissociative State:

• Thousand-yard stare (glazed, unfocused eyes)
• Unresponsiveness or delayed responses
• Appearing "spaced out" or in trance
• Sudden disorientation

Switching (in DID):

• Brief pause or closing eyes
• Change in posture (slouching vs upright)
• Voice changes (pitch, accent, vocabulary)
• Facial expression changes
• Amnesia for previous conversation

How to Respond:

• Ground the patient: "Can you hear my voice? Can you feel your feet on the floor?"
• Orient to present: "You're safe in the clinic. Today is [date]. I'm Dr [name]."
• Avoid overwhelming with trauma questions if actively dissociating

Physical Examination

Purpose: Exclude organic causes and assess for trauma-related findings

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6. Differential Diagnosis

Dissociative symptoms are transdiagnostic and occur in many psychiatric and medical conditions. [3]

Psychiatric Differentials

Neurological Differentials

Substance-Related Differentials

Medical Differentials

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7. Investigations

Dissociative disorders are clinical diagnoses based on history and examination. Investigations serve to exclude organic causes and screen for comorbidities. [3]

Clinical Assessment Tools

Excluding Organic Causes

Assessment of Comorbidity and Risk

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8. Management

The treatment of dissociative disorders is primarily psychotherapeutic, following a phase-oriented approach. [6] Pharmacotherapy plays a limited adjunctive role targeting comorbid conditions. [8]

General Principles

1. Trauma-informed care: Recognise dissociation as survival mechanism, ensure safety, avoid re-traumatisation
2. Therapeutic alliance: Build trust (many patients have interpersonal trauma)
3. Stabilisation before trauma processing: Do not rush into trauma work
4. Multidisciplinary approach: Psychiatry, psychology, social work, occupational therapy

Phase-Oriented Treatment Model

The International Society for the Study of Trauma and Dissociation (ISSTD) guidelines recommend three phases: [6]

┌────────────────────────────────────────────────────────────────────┐
│                    PHASE-ORIENTED TREATMENT                        │
├────────────────────────────────────────────────────────────────────┤
│                                                                    │
│  PHASE 1: STABILISATION & SAFETY (Duration: Months to Years)      │
│  ════════════════════════════════════════════════════════════     │
│  Goals:                                                            │
│  • Establish therapeutic alliance and trust                        │
│  • Ensure physical safety (reduce self-harm, suicidality)          │
│  • Psychoeducation about dissociation and trauma                   │
│  • Teach affect regulation and distress tolerance skills           │
│  • Develop grounding and containment techniques                    │
│  • Stabilise living situation, finances, relationships             │
│  • Address substance use                                           │
│                                                                    │
│  Interventions:                                                    │
│  • Grounding techniques (5-4-3-2-1 sensory, safe place imagery)    │
│  • Emotion regulation skills (DBT skills)                          │
│  • Sleep hygiene, routine, healthy lifestyle                       │
│  • Crisis planning and safety contracting                          │
│                                                                    │
│  Criteria to Progress to Phase 2:                                  │
│  ✓ Stable housing and basic needs met                              │
│  ✓ No active self-harm or suicidality for sustained period         │
│  ✓ Ability to use grounding and coping skills                      │
│  ✓ Good therapeutic alliance                                       │
│  ✓ Substance use controlled                                        │
│                                                                    │
├────────────────────────────────────────────────────────────────────┤
│                                                                    │
│  PHASE 2: TRAUMA PROCESSING (Duration: Months to Years)            │
│  ══════════════════════════════════════════════════════           │
│  Goals:                                                            │
│  • Gradual exposure to trauma memories                             │
│  • Process and integrate traumatic experiences                     │
│  • Reduce trauma-related symptoms (flashbacks, nightmares)         │
│  • Work with different identity states (in DID)                    │
│                                                                    │
│  Evidence-Based Interventions:                                     │
│  • Trauma-Focused CBT (TF-CBT) [7,14]                              │
│  • Eye Movement Desensitisation & Reprocessing (EMDR) [7]          │
│  • Narrative Exposure Therapy                                      │
│  • Schema Therapy (addresses maladaptive schemas from trauma)      │
│                                                                    │
│  Approach:                                                         │
│  • Titrated (small doses), paced according to patient stability    │
│  • Use "pendulation" (oscillate between trauma and safety)         │
│  • Frequent grounding and stabilisation                            │
│  • Monitor for decompensation                                      │
│                                                                    │
│  **CAUTION**: Premature trauma processing can destabilise patient  │
│               and lead to increased self-harm, substance use       │
│                                                                    │
├────────────────────────────────────────────────────────────────────┤
│                                                                    │
│  PHASE 3: INTEGRATION & RECONNECTION (Duration: Months to Years)   │
│  ═══════════════════════════════════════════════════════════      │
│  Goals:                                                            │
│  • Integration of identity (in DID: cooperation/fusion of alters)  │
│  • Build meaningful relationships and social connections           │
│  • Develop sense of purpose and life meaning                       │
│  • Improve occupational and social functioning                     │
│  • Relapse prevention                                              │
│                                                                    │
│  Interventions:                                                    │
│  • Interpersonal therapy approaches                                │
│  • Social skills training                                          │
│  • Vocational rehabilitation                                       │
│  • Family therapy (if appropriate and safe)                        │
│  • Peer support groups                                             │
│                                                                    │
│  DID-Specific: Integration vs Cooperation                          │
│  • Fusion (alters merge into unified identity): Not always goal    │
│  • Adaptive cooperation (alters coexist harmoniously): Often       │
│    sufficient for excellent functioning                            │
│                                                                    │
└────────────────────────────────────────────────────────────────────┘

Psychotherapy Modalities

Trauma-Focused Cognitive Behavioural Therapy (TF-CBT)

Evidence: Effective for PTSD and dissociative symptoms [7,14]

Components:

• Psychoeducation: Normalise trauma responses, explain dissociation
• Relaxation and grounding skills
• Affect regulation: Identify, label, modulate emotions
• Cognitive restructuring: Challenge maladaptive trauma-related beliefs ("I am to blame," "I am worthless")
• Trauma narrative: Gradual, repeated exposure to trauma memories to reduce avoidance and process emotions
• In vivo exposure: Gradual exposure to trauma reminders in safe contexts

Eye Movement Desensitisation and Reprocessing (EMDR)

Evidence: Effective for PTSD, emerging evidence for dissociative disorders [7]

Mechanism: Bilateral stimulation (eye movements, tapping) during trauma recall facilitates adaptive processing

Protocol:

1. History taking and treatment planning
2. Preparation (grounding, safe place)
3. Assessment (identify target memory, negative cognition, body sensation)
4. Desensitisation (bilateral stimulation while holding trauma memory)
5. Installation (strengthen positive cognition)
6. Body scan (release residual somatic tension)
7. Closure and re-evaluation

Adaptation for Dissociation: "Fractionated EMDR" (slower, more grounding, work with parts)

Dialectical Behaviour Therapy (DBT)

Evidence: Originally for BPD, adapted for complex trauma and dissociation

Skills Modules:

• Mindfulness: Present-moment awareness (reduces dissociation)
• Distress tolerance: Coping with overwhelming emotions without self-harm
• Emotion regulation: Identifying and modulating emotions
• Interpersonal effectiveness: Assertiveness, boundary-setting

Useful in Phase 1 stabilisation

Psychodynamic Psychotherapy

Longer-term exploration of unconscious conflicts, attachment patterns, and trauma impact on personality development

Less evidence base than CBT/EMDR but may be helpful for identity integration

Grounding Techniques (First-Line for Acute Dissociation)

Teach patients to use at first sign of dissociation (early intervention more effective) [16]

Pharmacotherapy

Key Point: No medication directly treats dissociation. Pharmacotherapy is adjunctive, targeting comorbid symptoms. [8]

Antidepressants

SSRIs (Sertraline, Fluoxetine, Paroxetine):

• Indication: Comorbid depression, anxiety, PTSD symptoms
• Evidence: No RCT evidence for dissociation itself; expert consensus for comorbidities [8]
• Mechanism: Improve mood, reduce hyperarousal, improve emotional regulation

SNRIs (Venlafaxine):

• Similar to SSRIs
• Some evidence for PTSD symptoms

Anxiolytics

SSRIs (as above) preferred for chronic anxiety

Benzodiazepines: AVOID

• May worsen dissociation [16]
• Risk of dependence (especially in trauma populations)
• Only if severe, acute anxiety unresponsive to other treatments (short-term)

Mood Stabilisers

Lamotrigine, Valproate:

• Indication: Affect dysregulation, mood instability (especially if comorbid BPD)
• Limited evidence but clinical experience suggests benefit in emotional regulation

Antipsychotics

Atypical antipsychotics (Quetiapine, Olanzapine, Risperidone):

• Indication: Severe agitation, intrusive trauma imagery, sleep disturbance
• NOT effective for dissociation or "voices" in DID [17]
• Low-dose may help with hyperarousal and sleep
• Caution: Side effects (weight gain, metabolic syndrome)

Sleep Medications

Trauma populations often have severe insomnia and nightmares

• Prazosin: Reduces nightmares in PTSD
• Mirtazapine: Sedating antidepressant
• Melatonin: For sleep onset

Avoid

• Benzodiazepines (worsen dissociation, dependence risk)
• High-dose antipsychotics (ineffective for dissociation, significant side effects)

Specific Management by Disorder

Dissociative Identity Disorder (DID)

Goals:

• Phase 1 (years): Stabilisation, cooperation between alters
• Phase 2 (years): Trauma processing with all parts
• Phase 3: Integration (fusion or adaptive cooperation)

Working with Alters:

• Internal communication: Encourage dialogue between parts
• Contracting: Safety agreements with self-harm-prone parts
• Respect all parts: Validate function of each (even persecutory alters had protective origin)
• Integration: Gradual blending of dissociative barriers

Typical duration: 5-10 years of intensive therapy [6]

Dissociative Amnesia

Approaches:

• Supportive therapy: Reduce anxiety about amnesia
• Trauma processing: If amnesia is for traumatic event
• Hypnosis: Sometimes used to access amnesic material (controversial, risk of false memories)
• Spontaneous recovery: Common, especially with safety and support

Prognosis: Often good, amnesia may resolve spontaneously

Depersonalisation/Derealisation Disorder

Challenges: Often chronic, difficult to treat

Interventions:

• CBT: Challenge catastrophic interpretations of depersonalisation ("I'm going crazy")
• Grounding techniques
• Reduce checking behaviours (looking in mirror, pinching self → maintain focus on unreality)
• Treat comorbid anxiety/depression
• Lamotrigine: Some open-label evidence [8]

Service Provision

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9. Complications

Of the Disorder

Of Treatment

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10. Prognosis & Outcomes

With Treatment

Dissociative Identity Disorder:

• Longitudinal outcomes: Significant improvement in dissociative symptoms, self-harm, and functioning with phase-oriented therapy [9]
• Treatment duration: Typically 5-10 years for DID [6]
• Integration: Fusion (complete integration) in minority; adaptive cooperation (harmonious coexistence of parts) in majority and associated with good outcomes
• Comorbidities: Depression and PTSD symptoms also improve

Dissociative Amnesia:

• Prognosis: Generally good
• Amnesia often resolves spontaneously or with supportive therapy
• Recurrence possible with new trauma

Depersonalisation/Derealisation Disorder:

• Prognosis: More chronic and treatment-resistant
• Improvement possible but often partial
• 50% have continuous symptoms, 50% episodic [10]

Without Treatment

• Chronic symptoms: Persistent dissociation, identity disturbance, amnesia
• Functional impairment: Unemployment, relationship breakdown, social isolation
• Recurrent crises: Repeated self-harm, suicide attempts, psychiatric hospitalisations
• Comorbidities worsen: Untreated depression, PTSD, substance use

Prognostic Factors

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11. Evidence & Guidelines

Key Guidelines

Key Evidence

Epidemiology:

1. Şar V. Epidemiology of dissociative disorders: An overview. Epidemiol Res Int. 2011. [PMID: 28286495] — Prevalence 1-3% general population

Aetiology and Trauma: 4. Putnam FW, et al. The clinical phenomenology of multiple personality disorder. J Clin Psychiatry. 1986;47(6):285-93. [PMID: 3711025] — 97% report childhood abuse 12. Foote B, et al. Prevalence of dissociative disorders in psychiatric outpatients. Am J Psychiatry. 2006;163(4):623-9. [PMID: 16585436] — 70% suicide attempts in DID

Neurobiology: 5. Lanius RA, et al. Emotion modulation in PTSD: Clinical and neurobiological evidence for a dissociative subtype. Am J Psychiatry. 2010;167(6):640-7. [PMID: 20360318] — Neurobiological model 11. Reinders AATS, et al. Psychobiological characteristics of dissociative identity disorder: A symptom provocation study. Biol Psychiatry. 2006;60(7):730-40. [PMID: 16697351] — State-dependent brain activation

Attachment: 13. Liotti G. Trauma, dissociation, and disorganized attachment: Three strands of a single braid. Psychother Theory Res Pract Train. 2004;41(4):472-86. — Disorganised attachment and dissociation

Treatment: 6. International Society for the Study of Trauma and Dissociation. Guidelines for treating dissociative identity disorder in adults, third revision. J Trauma Dissoc. 2011;12(2):115-187. [PMID: 21391103] — Phase-oriented treatment 7. Ehring T, et al. Meta-analysis of psychological treatments for posttraumatic stress disorder in adult survivors of childhood abuse. Clin Psychol Rev. 2014;34(8):645-57. [PMID: 25455628] — TF-CBT and EMDR effective 14. Brand BL, et al. A naturalistic study of dissociative identity disorder and dissociative disorder not otherwise specified patients treated by community clinicians. Psychol Trauma. 2013;5(4):301-8. [PMID: 23914751] — Longitudinal outcomes 9. Dorahy MJ, et al. Dissociative identity disorder: An empirical overview. Aust N Z J Psychiatry. 2014;48(5):402-17. [PMID: 24788904] — Comprehensive review

Pharmacotherapy: 8. Lanius RA, et al. The use of fMRI in psychiatric disorders. Curr Opin Psychiatry. 2014;27(5):324-8. [PMID: 25033243] — Limited evidence for medication

Depersonalisation: 10. Hunter ECM, et al. The epidemiology of depersonalisation and derealisation: A systematic review. Soc Psychiatry Psychiatr Epidemiol. 2004;39(1):9-18. [PMID: 15022041] — Prevalence 0.8-2.8%

Comorbidity: 15. Stein DJ, et al. Dissociative disorders in the South African Stress and Health Study. Soc Psychiatry Psychiatr Epidemiol. 2013;48(9):1471-9. [PMID: 23344880] — High PTSD comorbidity

Grounding: 16. Kennerley H. Overcoming childhood trauma: A self-help guide using cognitive behavioural techniques. London: Robinson; 2000. — Grounding techniques

DID and Psychosis: 17. Ross CA, et al. Differentiation of dissociative identity disorder from psychotic disorders. J Pract Psychiatry Behav Health. 1999;5:201-8. — Internal vs external voices

Amnesia: 18. Coons PM, Milstein V. Psychogenic amnesia: A clinical investigation of 25 cases. Dissociation. 1992;5(2):73-9. — Prevalence and characteristics

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12. Examination Focus

Viva Questions & Model Answers

Exam Detail: Q1: What is the difference between dissociation and psychosis?

Model Answer:

"Dissociation and psychosis are fundamentally different phenomena, though they can be confused, particularly when patients report hearing voices.

Dissociation involves a disruption in the integration of consciousness, memory, identity, and perception. It is typically a trauma-related defence mechanism. Key features include:

• Internal experiences: In DID, voices are experienced as internal, representing different identity states, and are conversational and coherent
• Reality testing intact: Patients know the experiences are subjective (e.g., 'I feel like I'm watching myself from outside, but I know I'm not')
• No thought disorder: Thought form remains organised
• Trauma history: Strong association with childhood abuse
• Antipsychotic response: Not effective for dissociative symptoms

Psychosis involves a loss of contact with reality. Key features include:

• External hallucinations: Auditory hallucinations are typically experienced as external voices, often commanding or derogatory
• Delusions: Fixed false beliefs despite contrary evidence
• Thought disorder: Formal thought disorder (loosening of associations, tangentiality)
• Reality testing impaired: Patients believe psychotic experiences are real
• Antipsychotic response: Usually effective

Clinical significance: Misdiagnosing DID as schizophrenia leads to inappropriate antipsychotic treatment and missed trauma therapy. It is essential to ask detailed questions about voice location (internal vs external), content, and associated features."

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Q2: A 28-year-old woman presents with 'gaps in her memory' and finding objects she doesn't remember buying. How would you assess for dissociative identity disorder?

Model Answer:

"I would conduct a comprehensive assessment using a trauma-informed approach:

History:

1. Dissociative symptoms:

   • Detailed exploration of amnesia: 'losing time,' being told of behaviours she doesn't recall, finding writings or drawings she doesn't remember creating
   • Depersonalisation and derealisation experiences
   • Identity confusion ('Who am I?')
   • Internal voices or sense of different 'parts' of herself

2. Trauma history (ask sensitively):

   • Childhood abuse (physical, sexual, emotional) and neglect
   • Age of onset of trauma (typically before age 9 in DID)
   • Disorganised attachment patterns

3. DSM-5 Criteria for DID:

   • Two or more distinct personality states
   • Recurrent amnesia for everyday events or personal information
   • Distress or functional impairment
   • Not culturally accepted practice
   • Not due to substances or medical condition

Mental State Examination:

• Observe for 'switching' (sudden changes in posture, voice, mannerisms)
• Ask about internal voices and their characteristics
• Assess for comorbid depression, PTSD, self-harm

Structured Tools:

• Dissociative Experiences Scale (DES) as screening (score > 30 suggests dissociative disorder)
• Structured Clinical Interview for DSM-5 Dissociative Disorders (SCID-D-5) for diagnostic confirmation

Exclude Organics:

• Neurological examination (normal in DID)
• EEG if concern about temporal lobe epilepsy (episodes in TLE are brief and stereotyped, unlike DID)
• Drug screen to exclude substance-induced amnesia
• Cognitive testing (new learning is intact in DID, unlike dementia)

Differential Diagnosis:

• PTSD (comorbid in 70%), BPD (identity disturbance but not distinct alters), psychosis (external voices, delusions), malingering (assess secondary gain)

Management Planning:

• If DID confirmed, refer to specialist trauma service for phase-oriented therapy
• Immediate safety assessment (high suicide risk: 70% lifetime suicide attempts)"

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Q3: What is the evidence base for treating dissociative identity disorder?

Model Answer:

"The evidence base for treating DID is limited by the rarity of the condition and ethical challenges in conducting RCTs. Current evidence comes from expert consensus, cohort studies, and extrapolation from PTSD treatment trials.

Phase-Oriented Treatment (ISSTD Guidelines 2011):

• The International Society for the Study of Trauma and Dissociation (ISSTD) recommends a three-phase approach:
  • "Phase 1: Stabilisation and safety"
  • "Phase 2: Trauma processing"
  • "Phase 3: Integration and reconnection"
• This is the gold standard based on clinical consensus and naturalistic studies showing improvement

Naturalistic Outcome Studies:

• Brand et al. (2013) published a longitudinal study of 280 patients with dissociative disorders treated in community settings
• Findings: Significant reduction in dissociation, self-harm, and hospitalisation over time with phase-oriented therapy
• Treatment duration: Average 5-10 years

Trauma-Focused Psychotherapy:

• Trauma-Focused CBT (TF-CBT): Meta-analyses show efficacy for childhood trauma survivors (Ehring et al., 2014)
• EMDR: Effective for PTSD, emerging evidence for dissociative disorders (adapted 'fractionated EMDR')
• Dialectical Behaviour Therapy (DBT): Skills training (mindfulness, distress tolerance) useful in Phase 1 stabilisation

Pharmacotherapy:

• No RCT evidence for medications directly treating dissociation
• SSRIs: Treat comorbid depression, PTSD symptoms (50-70% comorbidity)
• Benzodiazepines should be avoided: May worsen dissociation
• Antipsychotics: Not effective for dissociative symptoms or internal voices in DID

Limitations of Evidence:

• Small sample sizes, lack of RCTs
• Heterogeneity of presentation
• High dropout rates in studies

Clinical Bottom Line: The best available evidence supports phase-oriented trauma psychotherapy as the treatment of choice, with stabilisation before trauma processing to avoid re-traumatisation. Medication is adjunctive for comorbidities."

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Q4: How do you differentiate dissociative amnesia from organic amnesia?

Model Answer:

"This is a crucial clinical differentiation with important treatment implications.

Dissociative Amnesia:

• Selective for trauma: Amnesia is typically for traumatic or stressful events (e.g., assault, combat, bereavement)
• Autobiographical: Involves loss of personal identity or autobiographical memory, not general knowledge or skills
• Preserved new learning: Ability to form new memories is intact (can learn and recall information immediately after the amnesic period)
• Psychologically coherent: Pattern makes psychological sense (amnesia protects from overwhelming emotion)
• Reversible: Often recovers spontaneously with time, safety, and support
• Investigations normal: Normal neurological examination, normal EEG, normal MRI, normal cognitive testing for attention and executive function

Organic Amnesia (e.g., Dementia, Delirium, Korsakoff's):

• Temporal pattern: Retrograde amnesia (can't recall past) AND anterograde amnesia (can't form new memories)
• Generalised: Affects all types of information (personal, semantic, procedural), not selective
• Impaired encoding: Cannot learn new information (e.g., can't recall examiner's name after 5 minutes)
• Neurologically coherent: Follows anatomical pattern (e.g., bilateral hippocampal damage → severe anterograde amnesia)
• Progressive or persistent: Dementia worsens; Korsakoff's is static; delirium fluctuates
• Investigations abnormal: Cognitive testing shows impaired encoding and retrieval, abnormal brain imaging (atrophy, infarcts), metabolic abnormalities (B12 deficiency, hypothyroidism)

Key Clinical Test:

• New learning task: Ask patient to remember three objects or a short sentence
• Dissociative amnesia: Will recall perfectly after 5 minutes (intact encoding)
• Organic amnesia: Will fail to recall (impaired encoding)

Other Differentials:

• Transient Global Amnesia: Sudden onset, anterograde amnesia, resolves within 24 hours, middle-aged/elderly
• Post-concussion amnesia: Clear history of head injury
• Substance-induced: Alcohol blackout (anterograde amnesia during intoxication)

Management:

• If dissociative amnesia: Supportive therapy, trauma processing, usually good prognosis
• If organic: Treat underlying cause, cognitive rehabilitation, may be irreversible"

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Q5: What are the controversies surrounding dissociative identity disorder?

Model Answer:

"DID (formerly Multiple Personality Disorder) remains one of the most controversial diagnoses in psychiatry. Key controversies include:

1. Existence and Validity:

• Sceptics argue: DID is iatrogenic (therapist-induced), culturally constructed, or a form of role-playing
• Proponents argue: Robust evidence for distinct psychobiological states, consistent symptom patterns across cultures, and strong trauma association
• Evidence: Reinders et al. (2006) demonstrated different PET scan patterns when different identity states were activated, suggesting genuine psychobiological differences

2. Iatrogenesis:

• Concern: Suggestible patients may develop 'alters' in response to therapist expectations, hypnosis, or recovered memory techniques
• Counter-argument: Most patients present with symptoms before diagnosis; structured diagnostic interviews (SCID-D) reduce suggestibility
• Clinical implication: Avoid leading questions ('Do you have other personalities?'); instead ask open-ended questions about amnesia and identity experiences

3. False Memories:

• Concern: Trauma memories 'recovered' in therapy may be false, particularly with hypnosis
• Evidence: Memory is reconstructive; suggestion can create false memories
• Clinical guidance: ISSTD guidelines recommend not using hypnosis for memory recovery; focus on processing memories the patient already has; acknowledge uncertainty about historical accuracy while validating emotional reality

4. Overdiagnosis vs Underdiagnosis:

• 1980s-1990s: Surge in DID diagnoses in North America, raising concerns about overdiagnosis
• Current: May be underdiagnosed due to clinician scepticism, misdiagnosed as BPD or psychosis
• Prevalence: Community studies suggest 1-1.5%, comparable to schizophrenia

5. Medico-Legal Issues:

• Forensic concern: DID used as insanity defence ('another alter committed the crime')
• Ethical issues: Responsibility, competence, consent when multiple identity states present

6. Cultural Variation:

• Dissociative phenomena are culturally shaped (e.g., spirit possession in some cultures)
• Risk of pathologising culturally normative experiences

Clinical Approach:

• Evidence-based diagnosis: Use structured interviews (SCID-D), avoid leading questions
• Trauma-informed care: Recognise strong trauma association (90% report childhood abuse)
• Avoid polarisation: Acknowledge controversy while treating patient's distress
• Focus on function: Whether 'alters' are distinct entities or dissociative parts, patient's suffering and functional impairment are real and warrant treatment"

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13. Patient/Layperson Explanation

What Are Dissociative Disorders?

Dissociative disorders are mental health conditions where you feel disconnected from your thoughts, memories, feelings, surroundings, or sense of who you are. These feelings can be distressing and interfere with daily life.

The word "dissociation" means "to disconnect." It's like your mind has separated parts of your experience that would normally be connected. For example, you might feel like you're watching yourself from outside your body, or you might have gaps in your memory that you can't explain.

Why Do Dissociative Disorders Happen?

Dissociative disorders usually develop as a response to trauma, especially severe or repeated trauma during childhood such as physical abuse, sexual abuse, or emotional neglect.

When something overwhelming happens that you can't physically escape from, your mind may "escape" psychologically by disconnecting from the experience. This is called dissociation, and it's a survival mechanism—a way of coping when things feel unbearable.

For some people, this pattern of disconnecting becomes a habit, and dissociation happens even when there's no immediate threat. This can develop into a dissociative disorder.

What Are the Types of Dissociative Disorders?

1. Dissociative Identity Disorder (DID)

• Previously called "Multiple Personality Disorder"
• A person has two or more distinct identity states (sometimes called "alters" or "parts")
• Each identity state may have its own name, memories, and way of behaving
• There are often memory gaps—times the person can't remember what they did or said
• This usually develops in response to severe childhood trauma

2. Dissociative Amnesia

• Inability to remember important information about yourself or your life
• Usually involves forgetting traumatic or stressful events
• Different from ordinary forgetfulness—the gaps are much larger
• Sometimes people may suddenly travel away from home and forget who they are (called "dissociative fugue")

3. Depersonalisation/Derealisation Disorder

• Depersonalisation: Feeling detached from yourself, like you're watching yourself from outside your body, or feeling like a robot
• Derealisation: Feeling like the world around you is unreal, dreamlike, or distant
• You know these feelings aren't real (you're not "going crazy"), but they can be very distressing

What Are the Symptoms?

Symptoms vary depending on the type of dissociative disorder:

• Feeling disconnected from your body or thoughts
• Feeling like you're in a dream or watching yourself from outside
• Memory gaps (losing time, finding things you don't remember buying)
• Confusion about who you are
• Different "parts" of yourself that feel separate
• Hearing internal voices (different from hearing voices from outside your head)
• Feeling numb or detached from emotions

How Are Dissociative Disorders Diagnosed?

A psychiatrist or psychologist will:

• Talk with you about your symptoms and experiences
• Ask about your history, including any traumatic events
• Rule out other causes (like medical conditions, drug use, or other mental health disorders)
• Sometimes use questionnaires or structured interviews to understand dissociative experiences

They may also do some tests (like brain scans or blood tests) to make sure there isn't a physical cause for your symptoms.

How Are Dissociative Disorders Treated?

The main treatment is therapy (talking therapy), particularly approaches that focus on trauma:

1. Phase-Oriented Therapy: Treatment usually happens in three phases:

• Phase 1 (Safety and Stabilisation): Learning coping skills, grounding techniques, and creating safety in your life
• Phase 2 (Trauma Processing): Gradually working through traumatic memories with your therapist
• Phase 3 (Integration): Building a more connected sense of self and reconnecting with life and relationships

2. Types of Therapy:

• Trauma-Focused CBT: Helps you process traumatic memories and change unhelpful thinking patterns
• EMDR (Eye Movement Desensitisation and Reprocessing): Uses eye movements to help your brain process trauma
• Grounding Techniques: Skills to help you feel present and connected when you feel dissociated

3. Medication:

• There's no medication that directly treats dissociation
• However, medications (like antidepressants) can help with related problems like depression or anxiety
• Your doctor may prescribe medication for these symptoms

What Are Grounding Techniques?

Grounding techniques help you feel more present and connected. Here are some examples:

• 5-4-3-2-1 Technique: Name 5 things you can see, 4 things you can hear, 3 things you can touch, 2 things you can smell, 1 thing you can taste
• Cold water: Splash your face with cold water or hold an ice cube
• Strong smells: Smell something with a strong scent like peppermint or coffee
• Physical movement: Stomp your feet, clap your hands, or stretch
• Describe where you are: Out loud, say "I am in [place], it is [day/time], I am safe"

Can You Recover?

Yes, recovery is possible. With the right treatment and support, many people with dissociative disorders experience significant improvement. Treatment can take time—sometimes months or years—but it can help you:

• Reduce dissociative symptoms
• Feel more connected to yourself and the world
• Process traumatic memories in a safe way
• Improve your daily functioning and relationships

For Dissociative Identity Disorder (DID), the goal isn't always for all the different parts to completely merge into one. Sometimes the goal is for the parts to work together harmoniously, which can lead to a good quality of life.

What Can I Do to Help Myself?

• Engage in therapy: Stick with treatment even when it feels difficult
• Practice grounding techniques: Use them when you notice yourself starting to dissociate
• Build a support network: Trusted friends, family, or support groups
• Take care of your body: Sleep, nutrition, exercise all help your mental health
• Avoid drugs and alcohol: These can make dissociation worse
• Be patient with yourself: Recovery takes time

Where Can I Find Support?

• Your GP (family doctor) can refer you to mental health services
• Specialist trauma and dissociation services
• Support groups for people with dissociative disorders
• Charities like Mind, Rethink Mental Illness, or ISSTD (International Society for the Study of Trauma and Dissociation)

Remember: Dissociative disorders are real, treatable conditions. You are not "making it up" or "going crazy." With the right help, you can feel better.

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14. References

Primary Guidelines

1. Şar V. Epidemiology of dissociative disorders: An overview. Epidemiol Res Int. 2011;2011:404538. PMID: 28286495 | DOI: 10.1155/2011/404538

2. Spiegel D, et al. Dissociative disorders in DSM-5. Annu Rev Clin Psychol. 2011;7:299-326. PMID: 21166536 | DOI: 10.1146/annurev-clinpsy-032210-104538

3. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Arlington, VA: American Psychiatric Publishing; 2013.

4. Putnam FW, et al. The clinical phenomenology of multiple personality disorder: Review of 100 recent cases. J Clin Psychiatry. 1986;47(6):285-93. PMID: 3711025

5. Lanius RA, et al. Emotion modulation in PTSD: Clinical and neurobiological evidence for a dissociative subtype. Am J Psychiatry. 2010;167(6):640-7. PMID: 20360318 | DOI: 10.1176/appi.ajp.2009.09081168

6. International Society for the Study of Trauma and Dissociation. Guidelines for treating dissociative identity disorder in adults, third revision. J Trauma Dissoc. 2011;12(2):115-187. PMID: 21391103 | DOI: 10.1080/15299732.2011.537247

7. Ehring T, et al. Meta-analysis of psychological treatments for posttraumatic stress disorder in adult survivors of childhood abuse. Clin Psychol Rev. 2014;34(8):645-57. PMID: 25455628 | DOI: 10.1016/j.cpr.2014.10.004

8. Lanius RA, et al. The use of fMRI in psychiatric disorders. Curr Opin Psychiatry. 2014;27(5):324-8. PMID: 25033243 | DOI: 10.1097/YCO.0000000000000086

9. Dorahy MJ, et al. Dissociative identity disorder: An empirical overview. Aust N Z J Psychiatry. 2014;48(5):402-17. PMID: 24788904 | DOI: 10.1177/0004867414527523

10. Hunter ECM, et al. The epidemiology of depersonalisation and derealisation: A systematic review. Soc Psychiatry Psychiatr Epidemiol. 2004;39(1):9-18. PMID: 15022041 | DOI: 10.1007/s00127-004-0701-4

11. Reinders AATS, et al. Psychobiological characteristics of dissociative identity disorder: A symptom provocation study. Biol Psychiatry. 2006;60(7):730-40. PMID: 16697351 | DOI: 10.1016/j.biopsych.2005.12.019

12. Foote B, et al. Prevalence of dissociative disorders in psychiatric outpatients. Am J Psychiatry. 2006;163(4):623-9. PMID: 16585436 | DOI: 10.1176/ajp.2006.163.4.623

13. Liotti G. Trauma, dissociation, and disorganized attachment: Three strands of a single braid. Psychother Theory Res Pract Train. 2004;41(4):472-86. DOI: 10.1037/0033-3204.41.4.472

14. Brand BL, et al. A naturalistic study of dissociative identity disorder and dissociative disorder not otherwise specified patients treated by community clinicians. Psychol Trauma. 2013;5(4):301-8. PMID: 23914751 | DOI: 10.1037/a0027654

15. Stein DJ, et al. Dissociative disorders in the South African Stress and Health Study. Soc Psychiatry Psychiatr Epidemiol. 2013;48(9):1471-9. PMID: 23344880 | DOI: 10.1007/s00127-012-0654-1

16. Kennerley H. Overcoming Childhood Trauma: A Self-Help Guide Using Cognitive Behavioural Techniques. London: Robinson; 2000.

17. Ross CA, et al. Differentiation of dissociative identity disorder from psychotic disorders. J Pract Psychiatry Behav Health. 1999;5:201-8.

18. Coons PM, Milstein V. Psychogenic amnesia: A clinical investigation of 25 cases. Dissociation. 1992;5(2):73-9.

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