Difficulty: Intermediate | Prerequisites: Part 1 of Chapter 6 (Somatic Symptom and Related Disorders). Familiarity with basic memory processes (encoding, retrieval, retrograde vs. anterograde amnesia) is helpful.
Dissociative disorders involve disruptions in consciousness, memory, identity, or perception. Where somatic disorders express distress through the body, dissociative disorders express it through fragmentation of mental experience. These conditions have been controversial since they were first studied in the 19th century, and that controversy continues today, particularly around dissociative identity disorder and the concept of repressed memory. This section covers DID, dissociative amnesia (including dissociative fugue), and depersonalisation/derealisation disorder, along with the major theoretical debates you need to know for an exam.
Dissociative disorders involve a splitting of mental functions that normally work together: memory, identity, consciousness, and perception. The most dramatic form is dissociative identity disorder (multiple personalities), which is closely linked to severe childhood trauma. Dissociative amnesia involves memory gaps without new identities. The field remains divided on whether these conditions reflect genuine trauma responses or are partly created by suggestion and therapeutic practice.
Dissociation
A process in which components of mental experience (memory, identity, perception, consciousness) become split off from one another and may operate independently.
In simple terms, parts of your mind that normally work together stop communicating, so you might lose access to memories, feel detached from yourself, or experience separate identities.
Dissociative identity disorder (DID)
Formerly called multiple personality disorder. The person appears to have two or more distinct identities or personality states that regularly take control of behaviour. Each identity may have its own name, age, gender, mannerisms, and physiological responses.
Think of it as the most extreme form of dissociation: the mind creates separate "selves" that alternate in controlling the person's life.
Alter
A distinct identity or personality state within a person with DID. Alters can serve different functions (child alter, persecutor alter, protector alter) and may or may not be aware of one another.
Child alter
The most common type of alter. Does not age as the person ages. Often created during childhood trauma to take on the role of victim while the host personality psychologically escapes, or to serve as a protective "older sibling" figure.
Persecutor alter
An alter that inflicts pain or punishment on other alters, often through self-harm or dangerous behaviour. May believe it can hurt other alters without harming the physical body.
Protector (helper) alter
An alter that offers guidance to other alters or carries out functions the host personality cannot manage. May control switching between alters or act as a passive observer who can report on all the others.
Dissociative amnesia
Significant gaps in memory for personal information or life events, without the person developing new identities. The memory loss has psychological rather than organic causes.
In simple terms, the person forgets important things about themselves or their past, and the forgetting is driven by psychological stress rather than brain injury.
Dissociative fugue
A subtype of dissociative amnesia in which the person travels to a new location, may assume a new identity, and has no memory of their previous life. When the fugue ends, they return to their old identity with no memory of the fugue period.
Think of it as amnesia plus relocation: the person essentially starts a new life somewhere else, then snaps back.
Psychogenic amnesia
Memory loss arising in the absence of brain injury or disease, presumed to have psychological causes. Primarily involves retrograde amnesia (loss of past memories) rather than anterograde amnesia (inability to form new memories).
Anterograde amnesia
Inability to form new memories after the onset of the condition. Typical of organic brain damage rather than psychological causes.
Retrograde amnesia
Inability to recall memories from before the onset of the condition. In organic causes, personal identity is usually preserved; in psychological causes, personal identity is often lost while general knowledge is retained.
Korsakoff's syndrome
Global retrograde amnesia caused by chronic alcohol abuse. The person cannot remember personal or general information, sometimes spanning years or decades.
Depersonalisation/derealisation disorder
Frequent episodes of feeling detached from one's own mental processes or body, as though observing oneself from outside. Diagnosed when episodes are frequent enough to interfere with functioning.
In simple terms, the person feels like they are watching their own life from a distance, and it happens often enough to be distressing and disabling.
Hidden observer (Ernest Hilgard)
A concept from hypnosis research. Hilgard proposed that consciousness operates in two modes: an active mode (conscious plans, decisions, voluntary actions) and a passive receptive mode (registering and storing information without awareness). In most people these modes integrate seamlessly; in dissociative disorders, they split apart and operate independently.
Sociocognitive model of DID
The theory that alters are not autonomous identities but rather roles that patients adopt, influenced by cultural narratives about DID, therapeutic suggestion, and media exposure. Proponents argue DID is not fabricated but is a coping strategy reinforced by attention and the explanatory framework of the diagnosis itself.
Ataque de nervios
A culturally accepted reaction to stress among Latino populations, involving transient loss of consciousness, convulsive movements, hyperactivity, and impulsive acts. DID symptoms in Latino patients may overlap with or present as this syndrome.
Interest in dissociation has waxed and waned since the 19th century. Key early figures include Charcot, Freud, Jung, James, and Pierre Janet.
Janet defined dissociation as a process where components of mental experience are split off from consciousness but remain accessible through dreams and hypnosis.
Interest declined around 1910 as behaviourism and biological psychiatry rejected the concepts of repression and hypnosis.
Ernest Hilgard's "hidden observer" research in hypnosis revitalised interest in dissociation by demonstrating that people can process and store information outside conscious awareness (e.g. hypnotised subjects recalling pain they were told not to feel; surgical patients recalling music played while anaesthetised).
The person presents with two or more distinct identities or personality states. Many have more than a dozen.
Each alter may differ in facial expressions, speech patterns, physiological responses, gestures, interpersonal style, and attitudes. Alters are often different ages and genders and serve specific psychological functions.
Child alters are the most common type.
Do not age as the individual ages.
Strongly associated with childhood trauma.
May have been created during a traumatic experience to take on the victim role while the host escapes psychologically, or to act as a protective figure.
When a child alter is in control, the adult body may speak and behave in a childlike manner.
Persecutor alters inflict pain or punishment on other alters through self-harm or risky behaviour. May hand control back to the host to deal with the consequences. May believe they can hurt other alters without harming themselves.
Protector or helper alters advise other alters, carry out tasks the host cannot, and sometimes manage switching between alters or observe and report on all of them.
People with DID report amnesia for periods when another alter is in control. Amnesia between alters can be one-way: one alter may know what another is doing while that alter is completely unaware of the first.
Practical signs include discovering unfamiliar objects (another alter purchased them), being approached by strangers who claim to know them (another alter formed the relationship), and receiving messages addressed to an unfamiliar name.
Studies show that information and memories can transfer between identities even when specific alters report amnesia.
Most DID patients are adult women.
PTSD is commonly comorbid with DID.
Children with DID show erratic school performance, antisocial behaviour, early substance use, PTSD symptoms (hypervigilance, flashbacks, nightmares), and unstable emotions.
Both children and adults with DID may report hearing voices or feeling that their actions are controlled by other personalities.
Rarely diagnosed before 1980; reported cases increased sharply after the DSM-III published formal criteria.
The increase may also reflect improved differentiation from schizophrenia, whose diagnostic criteria became more specific around the same time. Some earlier cases diagnosed as schizophrenia may have been DID.
Most mental health professionals remain reluctant to give this diagnosis.
Most people with DID have previously been diagnosed with at least three other disorders, commonly including another personality disorder. Some of those prior diagnoses may be secondary to or a consequence of DID.
DSM-5 changes:
Added "or an experience of possession" to make the criteria applicable across cultures, including non-Western presentations and possession experiences within Western subgroups.
Transitions between identities no longer need to be directly observed; self-report is sufficient.
Memory problems now include everyday events, not just traumatic ones.
DID is diagnosed more frequently in the United States. In Latino populations, DID symptoms may overlap with ataque de nervios.
Cross-cultural criticism: some believe the US over-diagnoses DID while other countries under-diagnose it.
Trauma-dissociation model: DID is viewed as a coping strategy developed by people who experienced intolerable, inescapable trauma.
Most people diagnosed with DID self-report being victims of chronic sexual or physical abuse during childhood, typically carried out by a parent or family member over an extended period.
Other associated traumas include kidnapping, natural disasters, war, famine, and religious persecution.
People with DID tend to be highly suggestible and hypnotisable. The theory holds that they use self-hypnosis to dissociate from trauma, creating alters that provide safety, security, and nurturing absent from their caregivers.
Retreating into alters becomes a chronic coping mechanism.
Sociocognitive model: Alters are not autonomous personalities but roles adopted by patients who find DID a fitting narrative for their experiences.
Identities are metaphors patients use to understand their subjective experience, not discrete entities.
The person is not faking; they are playing roles that help them cope with life stressors, reinforced by attention from others and the explanatory framework of the diagnosis.
Critics argue DID may be partly a creation of psychotherapy and media representation rather than a natural disorder.
DID may have a genetic component; it appears to run in some families.
The goal is integration: merging all alters into one coherent personality.
The process involves giving voice to each alter, making them aware of one another, identifying each alter's function, working through the trauma each alter represents, and negotiating unification into a single personality with adaptive coping strategies.
Rebuilding the patient's capacity for trusting, healthy relationships is central, since trauma has typically destroyed their ability to trust.
Building a therapeutic alliance is critical and often slow.
Hypnosis is sometimes used as a therapeutic tool.
Possession-form DID may require culturally adaptive treatment approaches.
The person has significant memory gaps for personal facts and identity but does not develop new personalities.
Typically aware of gaps in their memory.
Organic amnesia (from brain injury, disease, drugs, accidents, or surgery) usually involves both anterograde and retrograde amnesia.
Psychogenic amnesia (no brain injury) rarely involves anterograde amnesia. It primarily involves retrograde amnesia and can last for extended periods.
An important pattern difference:
Organic retrograde amnesia: the person forgets personal and general information but usually retains their sense of identity (knows their own name).
Psychogenic retrograde amnesia: the person loses their identity and personal information but retains general knowledge.
Alcohol-related memory loss is common during intoxicated periods. Chronic alcohol abuse can lead to Korsakoff's syndrome, a global retrograde amnesia spanning years or decades.
The person travels to a new location, may adopt a new identity, and has no memory of their previous life.
They behave normally in the new environment and do not find it strange that they cannot recall their past.
When the fugue ends, they return to their previous identity and life, with no memory of the fugue period.
Autobiographical memory loss from fugue can be long-lasting and resistant to relearning.
Episodes may last days or years. Some people experience repeated fugue states; others have a single episode.
Theorists argue psychogenic amnesias result from using dissociation as a defence against intolerable memories.
Amnesia for a specific event may occur because extreme stress prevents the person from encoding the event in the first place.
Amnesias for specific time periods around a trauma are relatively common; generalised retrograde amnesia covering the entire past is rare.
Diagnostic challenge: It can be difficult to tell whether amnesia is genuine or faked to avoid consequences. People with financial, sexual, or drug-related legal problems are more likely to fake amnesia. There is no reliable method to distinguish true from feigned amnesia.
Hypnosis is sometimes used to recover memories when amnesia is thought to be psychological, but hypnosis can also create false memories.
People with dissociative amnesia or fugue may recover spontaneously.
Psychotherapy treatment focuses on helping the person recall and understand the trauma behind the dissociation.
Characterised by frequent episodes of feeling detached from one's own mental processes or body, as though one is an outside observer.
Occasional depersonalisation is normal (e.g. during sleep deprivation), but the disorder is diagnosed when episodes are frequent and disabling.
Average age of onset: 23.
Most patients carry at least one other psychiatric diagnosis, most commonly depression.
History of childhood emotional, physical, or sexual abuse is commonly reported.
There is ongoing debate about whether dissociative disorders are valid diagnostic categories.
Critics argue the disorders can be artificially created in suggestible clients by clinicians.
The controversy intensified when adults began recovering memories of childhood abuse during therapy, which proponents interpret as evidence of repressed memories (a form of dissociative amnesia).
Evidence for repressed memories comes from studies of people with documented abuse who later claim to have forgotten or repressed the experience for a period. Opponents challenge the methodology of these studies and whether forgetting is the same as repression.
Elizabeth Loftus's research demonstrated that false memories (e.g. being lost in a shopping centre as a child) can be implanted in adults through suggestion, and that procedures mimicking psychotherapeutic techniques can increase the rate of false memory formation.
Suggesting that dreams reflect repressed childhood events led a majority of subjects to report that dream-depicted events had actually happened.
Richard McNally found that people reporting recovered memories of abuse (and even of alien abductions) show a greater tendency to form false memories in lab experiments, suggesting a particular information-processing style.
Jennifer Freyd countered that McNally's cognitive tasks did not test the specific cognitive mechanisms involved in dissociation, and argued that people who dissociate and forget abuse are most likely to differ from others on tasks requiring split attention, which is the cognitive skill central to dissociation.
The controversy is unlikely to be resolved soon. Researchers on both sides apply different scientific frameworks, and people with genuine distressing symptoms remain caught in the middle.
Dissociative amnesia and fugue have direct relevance in forensic psychology, where courts must determine whether a defendant's claimed memory loss is genuine or fabricated. DID is relevant to clinicians working with survivors of severe childhood trauma. The repressed-memory debate matters to anyone in therapy, law enforcement, or the legal system, because the question of whether a recovered memory is reliable has consequences for criminal prosecutions and civil cases.
Students often confuse DID with schizophrenia. DID involves multiple distinct identities; schizophrenia involves disorganised thinking, hallucinations, and delusions, not separate personalities.
Students sometimes assume all alters are aware of each other. Amnesia between alters can be one-way, and some alters may be completely unaware of others.
Students frequently believe that psychogenic amnesia works the same way as organic amnesia. It does not. Psychogenic amnesia primarily involves retrograde memory loss and loss of personal identity, while organic amnesia typically involves both anterograde and retrograde loss but preserves personal identity.
Students may think the sociocognitive model of DID claims patients are deliberately faking. It does not. The model says patients adopt roles that help them cope, reinforced by therapeutic and social context, not that they are consciously lying.
⚠️ Know the differences between organic and psychogenic amnesia, especially the pattern reversal (organic preserves identity but loses general information; psychogenic loses identity but preserves general information).
⚠️ Be prepared to compare and contrast the trauma-dissociation model and the sociocognitive model of DID. Exam questions often ask you to evaluate evidence for each.
⚠️ Understand how the DSM-5 changed the DID criteria (added possession experiences, allowed self-reported identity transitions, expanded memory problems beyond traumatic events).
⚠️ The Loftus false-memory research is a frequently tested topic. Know what the study demonstrated and its implications for repressed-memory claims.
⚠️ Be able to distinguish dissociative amnesia, dissociative fugue, and DID from one another.
True or False: In psychogenic amnesia, the person typically cannot form new memories (anterograde amnesia).
Fill in the blank: The most common type of alter in DID is the __________ alter.
True or False: The sociocognitive model of DID argues that patients are consciously faking their symptoms.
Fill in the blank: __________ syndrome is a global retrograde amnesia caused by chronic alcohol abuse.
True or False: The DSM-5 requires that identity transitions in DID must be directly observed by a clinician.
(Answers: 1. False (psychogenic amnesia primarily involves retrograde amnesia), 2. child, 3. False (it argues patients adopt roles that help them cope, not that they are faking), 4. Korsakoff's, 5. False (self-report is now sufficient))
Q: What is the key difference between dissociative amnesia and dissociative identity disorder?
A: Dissociative amnesia involves significant memory gaps without the person developing new identities or personality states. DID involves the presence of two or more distinct identities that take control of behaviour, often with amnesia between them.
Q: Describe two functions that alters may serve in DID, according to the trauma-dissociation model.
A: Child alters may be created to take on the victim role during trauma so the host can psychologically escape. Protector alters provide safety, guidance, or carry out functions the host cannot manage. Both serve as coping mechanisms for inescapable trauma.
Q: How does retrograde amnesia differ in organic vs. psychological causes?
A: Organic retrograde amnesia causes the person to forget personal and general information about their past but usually preserves their personal identity (they know who they are). Psychogenic retrograde amnesia causes loss of personal identity and personal information while general knowledge (facts about the world) is retained.
Q: What did Elizabeth Loftus's research demonstrate, and why is it relevant to the repressed-memory debate?
A: Loftus showed that false memories can be implanted in adults through suggestion (e.g. convincing people they were lost in a shop as children when they were not). This is relevant because it raises the possibility that "recovered" memories in therapy could be false memories created by the therapeutic process rather than genuine recollections of past events.
Q: What are three key changes the DSM-5 made to the diagnostic criteria for DID?
A: The DSM-5 added "or an experience of possession" to encompass cross-cultural presentations. It allowed identity transitions to be self-reported rather than requiring direct observation. It expanded the memory criterion to include everyday events, not just traumatic experiences.
This material links to memory and cognition (introductory psychology), since understanding anterograde vs. retrograde amnesia and the mechanisms of encoding and retrieval is essential to grasping dissociative amnesia. The repressed-memory debate connects to research methods and the psychology of eyewitness testimony. DID connects to trauma and PTSD (covered earlier in the course), and the sociocognitive model connects to social psychology concepts like role theory and social reinforcement.
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