Dissociation, Depersonalisation and Derealisation

Dissociation refers to a range of experiences involving disruption or disconnection in normally integrated aspects of awareness, memory, perception or identity. The term is used at different levels: to describe an experience, a symptom dimension, a feature of another condition or a dissociative disorder. These uses should not be collapsed into a single diagnosis or a single explanation of what caused the experience.

In therapeutic practice, precision matters because superficially similar descriptions can have different meanings. A person saying that they feel distant, numb or unreal needs an opportunity to describe the experience in their own terms. A practitioner should not infer dissociation solely from silence, gaze direction, a change in pronouns or an unexpected response to an exercise.

Depersonalisation involves a sense of detachment from one's self, body or mental activity; derealisation involves a sense that surroundings are unreal or unfamiliar. In depersonalisation/derealisation disorder, reality testing is retained: the person recognises the unreality as an experience rather than accepting it as a literal transformation of the world. Persistent or recurrent symptoms with significant distress or impairment require assessment, including consideration of other psychiatric, substance-related or medical explanations. A transient experience is not, by itself, the disorder. ¹⁾

As a fictional illustration, 'the room feels dreamlike, although I know I am here' conveys something different from an unshakeable conviction that the room has physically ceased to exist. This contrast helps clarify language; it is not a diagnostic test. Insight, associated symptoms, course and context require professional assessment, and people may struggle to explain experiences that are frightening or unfamiliar.

Emotional numbing is also not a sufficient diagnosis. When a client says they feel nothing, useful clarification concerns what is absent, when it began, whether it occurs outside sessions and how it affects functioning. Assuming that every absence of emotion represents dissociation can close down other explanations before they have been considered.

The National Center for PTSD describes the dissociative subtype of PTSD principally in terms of depersonalisation and derealisation in someone who meets PTSD criteria. It is not a label for every person who sometimes feels detached. ²⁾ Complex PTSD is a separate category in ICD-11; the WHO's diagnostic manual is intended to support appropriately qualified clinical diagnosis. The existence of these categories does not establish that a particular individual's difficulties fit one of them. ³⁾

Dissociative identity disorder is another distinct clinical presentation. The ISSTD's 2011 specialist guidance addresses DID and closely related dissociative disorders in adults, rather than all dissociative experiences. It represents expert consensus informed by the literature and clinical practice. Its age and specialist scope should be visible whenever it is used; it is not a recent randomised trial or a general IEMT protocol. ⁴⁾

More recent evidence is available. Griffiths and colleagues' 2025 systematic review included 19 treatment studies in adults with DID or other specified dissociative disorder; three examined phase-oriented treatment. Improvements were reported across several approaches, but the authors emphasised the need for adequately powered controlled trials. This is an emerging evidence base, not a demonstration that one treatment sequence is superior or that PTSD findings settle DID care. ⁵⁾

A practical editorial distinction is therefore to describe the observed problem before selecting a diagnostic label. Recurrent gaps in recall, experiences of detachment and a well-established diagnosis of DID call for different levels of enquiry. A general trauma history cannot determine which is present, and a treatment brand cannot substitute for the relevant assessment.

Assessment needs to clarify the form of the experience, frequency, duration, triggers, associated distress and effect on everyday activities. It also matters whether the experience occurs during a session, across the preceding week, or as a longstanding tendency. Those reference periods are not equivalent. A person may report substantial difficulties between appointments while appearing settled during the consultation.

The Dissociative Symptoms Scale assesses clinically relevant dissociative symptoms over the past week. The National Center for PTSD describes a 20-item version and an eight-item brief version, covering domains such as gaps in awareness or memory and altered perceptions of self or surroundings. The available evidence supports their use as symptom measures in studied populations; the official guidance also notes limitations in establishing broadly representative cutoff values. They are not self-sufficient diagnostic procedures or universal permission tests for trauma therapy. ⁶⁾

A questionnaire can provide a structured starting point, but the meaning of an endorsed item still needs clarification. Repeated measurement is most interpretable when the instrument, reference period and conditions remain comparable. A score taken after an unusually difficult week should not be treated as a timeless description of the person. Nor should a lower score be assumed to represent improvement if the person is misunderstanding the questions or has stopped reporting concerns.

The difference between state and longer-term symptom measurement also matters in research. A study of baseline dissociation as a predictor of outcome does not automatically explain the effect of becoming detached during a particular therapeutic task. The time at which a variable is measured limits the question the study can answer.

Hoeboer and colleagues' 2020 meta-analysis included 21 trials with 1,714 people receiving psychotherapy for PTSD. Its abstract reports:

Pre-treatment dissociation was not related to treatment effectiveness in patients with PTSD

The pooled correlation was 0.04, with a 95% confidence interval from −0.04 to 0.13. However, the included studies differed substantially, some had methodological limitations, and most analyses concerned treatment completers. The result challenges a blanket assumption that baseline dissociation inevitably prevents benefit from PTSD treatment. It does not establish that every dissociative presentation is equally suitable for every procedure, or answer treatment questions about DID. ⁷⁾

Later evidence warrants attention. Kleindienst and colleagues' 2025 analysis involved 193 women with childhood-abuse-related PTSD enrolled in a trial comparing DBT-PTSD and cognitive processing therapy. Higher baseline dissociation predicted less improvement after accounting for initial PTSD severity, while early reduction in dissociation was associated with later benefit. This was a predictor analysis within a randomised treatment trial: dissociation itself was not randomly assigned or experimentally reduced as an isolated intervention. It therefore does not prove that a mandatory stabilisation phase causes better outcomes. The population and treatments also differ from many community presentations and from IEMT. ⁸⁾

These findings should be read together. A pooled average across varied studies and a predictor result within a particular trial can differ without either making the other irrelevant. They support assessment and monitoring rather than two categorical claims: that dissociation always contraindicates trauma-focused treatment, or that it never affects how treatment should be delivered.

If the person seems less able to follow the discussion, the immediate task is to establish what they are experiencing and whether they want to continue. An interpretation such as 'the trauma is releasing' should not replace this enquiry. Describe observations in ordinary language and avoid treating the practitioner's theory as an explanation the client must accept.

Grounding is commonly intended to support attention to the present situation. VA field guidance notes that it can be counterproductive and should be stopped if it increases frustration. That source is practical guidance for police encounters, not trial evidence for a psychotherapy protocol; its relevant lesson is responsiveness to the person's reaction. ⁹⁾

An editorial session plan might specify how to pause, how the person can communicate difficulty, what helps them remain oriented, and what circumstances require ending the exercise or obtaining additional help. These arrangements should be agreed before relying on them during distress. They should not involve forced disclosure, unexpected touching or escalating stimulation to obtain a desired response.

A brief change in reported distress is not sufficient evidence that the underlying difficulty has resolved. Review orientation, the person's account of the experience and their ability to resume ordinary activities. New or unexplained symptoms require consideration beyond the treatment model, especially when they recur, impair functioning or differ markedly from the person's established pattern.

Dissociative symptoms do not establish that a particular historical event occurred. The ISSTD guidance advises a respectful neutral stance and avoidance of suggestive or leading approaches to memory. ¹⁰⁾ A therapist can take a person's distress seriously while remaining clear about what is remembered, inferred, imagined or independently corroborated.

For example, asking someone to describe a reported gap in awareness is different from asking which hidden identity took control. The second question imports an explanation. Similarly, an exercise intended to reduce distress should not be presented as a method of verifying memories. Changes in emotional intensity, vividness or confidence cannot, by themselves, establish historical accuracy.

This distinction is particularly relevant to an eye movement wiki. Observations made while following a target or recalling an image may be clinically interesting, but their interpretation requires evidence. They should not be used as stand-alone markers of a dissociative disorder, proof of concealed abuse or proof that a memory has been fully processed.

In a fictional consultation, Alex reports becoming distant when discussing an upsetting event. The practitioner first asks what distant means and learns that the room feels unreal, awareness remains intact and the experience also occurs at work. Rather than intensifying the exercise to break through the response, they pause, discuss the pattern and consider appropriate assessment. Alex's account and functional difficulties become part of the plan.

If assessment later supports PTSD treatment, the decision still requires matching the intervention and practitioner to Alex's needs. The studies above concern specified PTSD therapies and populations; they do not demonstrate the effectiveness or safety of IEMT for dissociative disorders. Any proposed IEMT work should therefore avoid borrowing a conclusion from a different intervention or presenting absence of direct evidence as reassurance.

This selective review was checked on 8 October 2026. It distinguishes clinical descriptions, specialist consensus, instrument guidance and empirical treatment research. The examples are fictional and the practical organising suggestions are editorial synthesis. The article is not a diagnostic manual or clinical practice guideline and has not undergone independent clinical peer review.

• Assessment, Suitability and Referral
• Stabilisation, Grounding and Therapeutic Pacing
• Adverse Effects, Deterioration and Non-Response
• Autobiographical Memory and the Self
• False Memory Syndrome
• Start Here

Brief quoted extracts remain attributable to their original authors and rights holders.