Difficulty: Intermediate | Prerequisites: General introduction to abnormal psychology (Chapters 1-5), companion notes on somatic symptom disorders
These notes cover the dissociative disorders from the second half of Chapter 6. Dissociative disorders involve disruptions in consciousness, memory, identity, or perception. They are among the most debated diagnoses in psychology. You should already understand basic DSM-5 structure and be familiar with the somatic disorders from the first half of this chapter, as several concepts (conversion, the mind-body relationship, the role of trauma) carry across both halves.
Dissociative disorders involve a disruption in the normally integrated functions of consciousness, memory, identity, or perception. The major disorders are dissociative identity disorder (multiple distinct personalities), dissociative amnesia (inability to recall important autobiographical information, sometimes with fugue), and depersonalisation/derealisation disorder (feeling detached from yourself or your surroundings). These disorders are strongly linked to trauma, highly controversial in terms of validity, and among the most debated diagnoses in the field.
Dissociation
A process in which components of mental experience are split off from consciousness but remain accessible through dreams and hypnosis. Think of it as: parts of your mind operating independently without your awareness, like a background process running on a computer you cannot see.
Dissociative identity disorder (DID)
A disorder characterised by the presence of two or more distinct personality states (alters) that recurrently take control of the individual's behaviour, accompanied by gaps in memory. Formerly called multiple personality disorder.
Alters (alternate identities)
The distinct personality states in DID. Each alter may have its own name, age, gender, speech patterns, physiological responses, and way of relating to the world.
Host personality
The primary identity that presents most of the time and often is not aware of the other alters. In the trauma model, the host escapes into "psychological oblivion" while child alters bear the traumatic experience.
Child alter
The most common type of alter. Often represents the victim role during the original trauma, absorbing the experience so the host does not have to.
Persecutor personality
An alter that inflicts pain or punishment on the other personalities, often through self-mutilative behaviours (cutting, burning, suicide attempts). Persecutor alters may believe they can harm other personalities without harming the shared body.
Protector/helper personality
An alter that offers advice to other personalities, sometimes controls the switching between alters, or acts as a passive observer who can report on the thoughts and intentions of all other personalities.
Dissociative amnesia
Significant periods of amnesia in which a person cannot remember important autobiographical information, usually of a traumatic or stressful nature. The memory gaps are inconsistent with ordinary forgetting.
Dissociative fugue
A subtype of dissociative amnesia in which the person travels to a new location and assumes a new identity with no memory of their previous life. The person may behave normally in the new environment and, upon recovery, have no memory of the fugue period.
Depersonalisation
Experiences of unreality, detachment, or feeling like an outside observer with respect to one's own thoughts, feelings, sensations, body, or actions. In simple terms, feeling as though you are watching yourself from outside your own body.
Derealisation
Experiences of unreality or detachment with respect to one's surroundings, as though the world is dreamlike, foggy, or not quite real.
Hidden observer (Hilgard)
Hilgard's concept that consciousness has an active mode and a passive receptive mode. The passive mode stores information in memory without conscious awareness of its processing. In simple terms, part of your mind is always recording, even when you are not aware of it.
Sociocognitive model (of DID)
The theory that alternate identities are not true, distinct personalities but rather a narrative or metaphor adopted by patients to make sense of their experiences. The patients are not faking, but they are playing out roles that help them cope with stress, reinforced by attention from others and by the therapeutic context.
Organic amnesia
Memory loss resulting from brain injury caused by disease, drugs, accidents, or surgery. Includes both anterograde and retrograde forms. In organic retrograde amnesia, both personal and general information are typically affected.
Psychogenic amnesia
Memory loss in the absence of any brain injury or disease, believed to have psychological causes. Typically affects personal information (not general knowledge) and rarely involves anterograde amnesia.
Anterograde amnesia
Inability to form new memories after the event that caused the amnesia. Think of it as: everything before the injury is intact, but you cannot record new experiences.
Retrograde amnesia
Inability to remember information from before the event that caused the amnesia. Think of it as: your older memories are lost, but you can still form new ones.
Korsakoff's syndrome
A condition caused by chronic alcoholism that produces global retrograde amnesia, in which the person cannot remember personal or general information for a period of several years or decades.
Ataque de nervios
A culturally accepted reaction to stress among Latinos that involves transient periods of loss of consciousness, convulsive movements, and hyperactivity. Relevant to understanding how culture shapes the expression of dissociative experiences.
Dissociation refers to a splitting of mental experience from consciousness. The dissociated material does not vanish; it remains accessible through dreams and hypnosis.
Interest in dissociation waned around 1910 as behaviourism and biological approaches gained dominance. These frameworks rejected the concept of repression and the use of techniques like hypnosis
Hilgard revitalised the field with the hidden observer phenomenon
Hilgard proposed that consciousness operates in two modes: an active mode (what you are aware of) and a passive receptive mode that stores information without your conscious knowledge of the processing.
In experiments, participants were hypnotised and told they would feel no pain during a painful procedure, but that they could recall the pain when given a specific cue
During the procedure, participants reported no awareness of pain. When cued afterwards, they described the pain matter-of-factly, as though a separate, rational observer had registered the experience
Supporting evidence: anesthetised surgical patients have been shown to recall specific pieces of music played during their surgery, despite being unconscious
Normally, the active and receptive modes of consciousness work together so seamlessly that we do not notice any division between them. In dissociative disorders, this integration breaks down, and the person becomes aware of (or impaired by) the disconnection between these modes.
The cardinal symptom is the presence of two or more distinct personality states (alters or alternate identities), each with its own way of perceiving and relating to the world
Alters may have distinct facial expressions, speech characteristics, physiological responses, gestures, interpersonal styles, and attitudes. They are often different ages and genders and serve specific functions
Child alters are the most common type. They typically take on the victim role in the original trauma while the host personality retreats into psychological oblivion
Persecutor personalities inflict pain and punishment on other alters through self-mutilative behaviours (cutting, burning, suicide attempts). They engage in dangerous behaviour and then withdraw, leaving the host to experience the pain. They may believe they can harm other personalities without harming themselves
Protector/helper personalities offer advice, sometimes control the switching between alters, or act as passive observers who can report on all other alters' thoughts and intentions
Significant periods of amnesia or "blank spells" are common. People with DID describe being amnesic for periods when other personalities are in control, or experience one-way amnesia between personalities
PTSD is frequently comorbid. Self-injurious behaviour is common: 75% have a history of suicide attempts and 90% have suicidal thoughts
In children: hypervigilance, flashbacks, traumatic nightmares, exaggerated startle response
Many report hearing voices that tell them to do harmful things
The majority of diagnosed cases are adult women
A. Disruption of identity characterised by two or more distinct personality states (may be described as an experience of possession in some cultures). Involves marked discontinuity in sense of self and agency, with alterations in affect, behaviour, consciousness, memory, perception, cognition, and/or sensory-motor functioning. May be observed by others or self-reported
B. Recurrent gaps in the recall of everyday events, important personal information, and/or traumatic events, inconsistent with ordinary forgetting
C. Symptoms cause clinically significant distress or impairment in functioning
D. The disturbance is not a normal part of broadly accepted cultural or religious practice. In children, symptoms are not better explained by imaginary friends
E. Symptoms are not attributable to a substance or another medical condition
DID was rarely diagnosed before 1980, then cases increased dramatically. Several factors contributed:
First included as a diagnostic category in the DSM-III in 1980
The criteria for schizophrenia were made more specific, meaning cases that would previously have been diagnosed as schizophrenia were now recognised as DID
Influential papers by psychiatrists described DID cases in detail
Most people with DID have been previously diagnosed with three or more other disorders: 97% have depression, 90% have an anxiety disorder (usually PTSD), 65% have substance abuse, 38% have an eating disorder. Earlier diagnoses may have been misidentifications of DID symptoms
The DSM-5's inclusion of possession as a manifestation of DID was significant for cultural relevance
DID is diagnosed most frequently in the United States
Ataque de nervios in Latino populations is a culturally accepted stress reaction involving transient loss of consciousness, convulsive movements, and hyperactivity
Trauma model: many theorists view DID as a coping strategy for intolerable trauma, an internal "divide and conquer" approach. In a study of 135 people with DID, 92% reported sexual abuse and 90% reported physical abuse, usually chronic and sustained over extended periods
People with DID are thought to be highly suggestible and hypnotisable
Sociocognitive model: alternate identities are created by patients who adopt the narrative of DID as an explanation that fits their experiences. The alters are not true personalities with clear-cut boundaries but rather a metaphor the patient uses to understand their subjective experience. The person is not faking; they are playing out a role that helps them cope with stress, reinforced by concern and attention from others
Familial patterns: DID appears to run in families, supported by family history studies and twin studies
The goal is to integrate all personalities into one and help the patient rebuild the capacity for trusting, healthy relationships.
The therapist "gives voice" to each identity, helps the identities become aware of one another, determines the role and function of each personality, helps each personality confront and work through the traumas that led to the disorder, and negotiates with the personalities for unification into a single identity with adaptive coping styles
Hypnosis is sometimes used as part of treatment
A condition involving significant periods of amnesia in which the person cannot remember important facts about their life and personal identity. They are typically aware that large gaps exist in their memory. Usually occurs after traumatic events.
A. Inability to recall important autobiographical information, usually of a traumatic or stressful nature, inconsistent with ordinary forgetting
B. Symptoms cause clinically significant distress or impairment in social, occupational, or other areas of functioning
C. Not attributable to the physiological effects of a substance or another medical condition
D. Not better explained by DID, PTSD, or other disorders
Organic amnesia: caused by brain injury from disease, drugs, accidents, or surgery
Anterograde amnesia: inability to remember new information formed after the injury
Psychogenic amnesia: occurs in the absence of brain injury or disease, believed to have psychological causes
Rarely involves anterograde amnesia (it is almost always retrograde)
Retrograde amnesia (common to both organic and psychogenic):
Organic retrograde amnesia: typically affects both personal and general information, but the person usually retains their sense of personal identity
Psychogenic retrograde amnesia: affects personal information but not general knowledge
Korsakoff's syndrome: caused by chronic alcoholism. Produces global retrograde amnesia in which neither personal nor general information can be recalled for a period of several years or decades
A subtype of dissociative amnesia in which the person travels to a new place and assumes a new identity with no memory of their previous life.
The person behaves quite normally in the new environment and finds it odd that they cannot remember their past
Upon recovery, they can return home and act normally with no memory of the fugue period
May be a single episode or repeated states
People sometimes fake dissociative amnesia to escape criminal responsibility. This is a genuine forensic concern, particularly in cases of unpremeditated killings where the perpetrator was in a state of extreme emotional arousal.
Involves frequent episodes in which the person feels detached from their own mental processes or body (depersonalisation), their surroundings (derealisation), or both.
Extremely common in mild, transient forms with sleep deprivation or drug use
Lifetime prevalence: 0.8-2.8% worldwide
Equally common among genders
Common in people with a history of abuse; 79% have impaired functioning in society
Crucially, reality testing remains intact during episodes. The person knows they are not literally outside their body or that the world has not literally changed; the experience simply feels that way
A. Persistent or recurrent experiences of depersonalisation, derealisation, or both
Depersonalisation: experiences of unreality, detachment, or being an outside observer with respect to one's thoughts, feelings, sensations, body, or actions
Derealisation: experiences of unreality or detachment with respect to surroundings (dreamlike, foggy)
B. During the experience, reality testing remains intact
C. Symptoms cause clinically significant distress or impairment in functioning
D. Not attributable to another medical or psychological condition
The dissociative disorders, and DID in particular, are among the most contested diagnoses in psychology.
Fewer than 25% of clinicians believe there is strong empirical evidence that DID is a valid diagnosis
Critics argue that DID is artificially created in suggestible clients by clinicians who inadvertently reinforce the creation of symptoms through leading questions and therapeutic expectations
The sociocognitive model supports this view: patients adopt the DID framework as a way to make sense of distressing experiences, rather than developing genuinely distinct personalities
A major controversy centres on repressed memories of childhood sexual abuse
Memory before age three tends to be unreliable and fragmentary
Research shows that repeatedly asking adults about childhood events that never happened leads 20-40% of them to "remember" these events as though they were real
This raises serious questions about whether therapeutic techniques designed to recover repressed memories may instead be implanting false ones
Students often confuse DID with schizophrenia. These are entirely different disorders. DID involves distinct personality states; schizophrenia involves psychotic symptoms such as hallucinations and disordered thinking. Before 1980, DID cases were often misdiagnosed as schizophrenia, which may be the source of the confusion
Students sometimes think dissociative amnesia means the person forgets everything. It does not. Psychogenic amnesia typically affects personal autobiographical information while leaving general knowledge intact
Students often assume depersonalisation means the person has lost touch with reality. It does not. Reality testing remains intact; the person knows the experience is abnormal, it simply feels as though they are detached
Students may think the sociocognitive model of DID means patients are faking. The model is more nuanced: patients are playing out a genuine coping role, not deliberately deceiving
⚠️ Be able to distinguish DID, dissociative amnesia, and depersonalisation/derealisation disorder from one another. Vignette-based questions are likely
⚠️ Know the DSM-5 criteria for DID, particularly Criterion A (two or more distinct personality states with discontinuity in sense of self and agency) and Criterion B (recurrent memory gaps)
⚠️ Understand the difference between organic and psychogenic amnesia, and between anterograde and retrograde amnesia. Exam questions frequently test these distinctions
⚠️ Know the comorbidity statistics for DID: 97% depression, 90% anxiety (usually PTSD), 65% substance abuse, 38% eating disorder. The 75%/90% suicide statistics may also appear
⚠️ Understand the debate around DID: the trauma model (DID as a coping response to abuse) vs. the sociocognitive model (DID as a role adopted with therapeutic reinforcement)
⚠️ The false memory research (20-40% "remember" events that never happened) is a key piece of evidence in the controversy around repressed memories
True or false: In depersonalisation/derealisation disorder, the person loses the ability to distinguish what is real from what is not. False. Reality testing remains intact.
Fill in the blank: The most common type of alter in DID is the ________ alter. Child alter.
True or false: Psychogenic amnesia typically involves both anterograde and retrograde amnesia. False. It rarely involves anterograde amnesia; it is almost always retrograde, affecting personal information.
Fill in the blank: In a dissociative fugue, the person travels to a new place and assumes a ________ with no memory of their previous life. New identity.
True or false: The majority of clinicians believe DID is a well-supported, valid diagnosis. False. Fewer than 25% believe there is strong empirical evidence for it.
Q: A woman is found in a city 300 miles from her home. She has assumed a new name, has a new job, and cannot remember anything about her previous life. When her family finds her, she returns home and has no memory of the period away. What disorder and subtype does this describe?
A: Dissociative amnesia with dissociative fugue. The defining features are travel to a new location, assumption of a new identity, amnesia for the previous identity, and (upon recovery) amnesia for the fugue period itself.
Q: What is the difference between organic retrograde amnesia and psychogenic retrograde amnesia?
A: Organic retrograde amnesia typically affects both personal and general information, though personal identity is usually retained. Psychogenic retrograde amnesia affects personal autobiographical information but leaves general knowledge intact.
Q: Describe the trauma model and the sociocognitive model of DID. How do they differ?
A: The trauma model views DID as a coping strategy developed in response to intolerable, chronic abuse (especially in childhood). The personality splits as an internal "divide and conquer" mechanism. The sociocognitive model proposes that alters are not true distinct personalities but rather roles adopted by suggestible patients, reinforced by therapeutic attention and the cultural narrative of DID. Both models agree the patients are not deliberately faking.
Q: A patient reports frequent episodes of feeling as though she is watching herself from outside her body. She knows this is not literally happening but finds it very distressing. Her neurological exams are normal. What disorder is this?
A: Depersonalisation/derealisation disorder. The key features are the experience of detachment from oneself (depersonalisation), intact reality testing, clinically significant distress, and no other medical or psychological explanation.
Q: Why did DID diagnoses increase dramatically after 1980?
A: Three factors: (1) DID was first included as a diagnostic category in the DSM-III in 1980. (2) Schizophrenia criteria were made more specific, so cases previously labelled schizophrenia were now recognised as DID. (3) Influential papers describing DID were published, raising clinician awareness.
Q: What evidence from false-memory research raises concerns about recovered memories of childhood abuse?
A: Research shows that memory before age three is unreliable, and that repeatedly asking adults about childhood events that never happened leads 20-40% of them to genuinely "remember" those events. This suggests therapeutic techniques designed to recover repressed memories may sometimes create false ones instead.
Q: What is Korsakoff's syndrome and how does it differ from typical psychogenic amnesia?
A: Korsakoff's syndrome is caused by chronic alcoholism and produces global retrograde amnesia: the person cannot remember either personal or general information for a period of several years or decades. Psychogenic amnesia, by contrast, affects personal information but leaves general knowledge intact.
Dissociative disorders connect directly to the somatic symptom disorders in the first half of this chapter (see companion study notes). Conversion disorder in particular shares conceptual ground with dissociation: both involve a breakdown in normally integrated psychological functions.
The role of trauma, especially childhood abuse, links this material to PTSD (covered in the anxiety/trauma chapters). Understanding PTSD comorbidity is important for the DID material in particular.
The controversy around DID and repressed memories connects to broader issues in the philosophy of science and clinical psychology: how do we validate diagnoses, and what are the ethical implications of therapeutic techniques that may create false memories?
Dissociation, dissociative disorders, dissociative identity disorder, DID, multiple personality disorder, alters, alternate identities, host personality, child alter, persecutor personality, protector personality, dissociative amnesia, dissociative fugue, depersonalisation, derealisation, depersonalisation/derealisation disorder, hidden observer, Hilgard, sociocognitive model, organic amnesia, psychogenic amnesia, anterograde amnesia, retrograde amnesia, Korsakoff's syndrome, ataque de nervios, false memories, repressed memories, DSM-5 dissociative disorders, abnormal psychology Chapter 6, Munchausen, conversion disorder overlap