Complex PTSD and dissociation

Complex PTSD and Dissociation: Why the Mind Steps Away, and How It Comes Back

There may be a particular kind of tiredness that brought you here. Not only the tiredness of remembering, but the tiredness of losing hours, of arriving somewhere without quite knowing how, of watching your own life from a short distance away and being unable to close the gap. If that is familiar, you are not failing at recovery. You are describing something that has a name, a mechanism, and a substantial body of research behind it.

Complex post-traumatic stress disorder (complex PTSD, often shortened to CPTSD) is a recognised condition that can follow prolonged or repeated trauma, particularly where escape was difficult or impossible. Dissociation is a disruption in the usual joining-up of memory, identity, emotion, perception and sense of body. The two are closely related, and for many people the dissociative part is the piece that is least understood by the people around them, and sometimes by clinicians too.

This article explains what complex PTSD is and how it differs from PTSD, what dissociation actually is at the level of the nervous system, why the two so often travel together, and what treatment and daily management look like. It sets out practical steps you can begin this week, and it is honest about what is still uncertain.

A note on limits before we start. This is educational information, not treatment, and it cannot diagnose you or replace work with a trauma-informed professional who knows your history. Recovery here is rarely quick and almost never tidy. What follows is offered as a map, not a schedule.

Disclosure: some book links in the Further Reading section are affiliate links. If you buy through them, this site may earn a small commission at no extra cost to you. Recommendations are made on merit, and we only link books we would suggest regardless.

What Complex PTSD Is

Complex PTSD became a formal diagnosis in 2019, when the World Health Organization included it in the eleventh revision of the International Classification of Diseases (ICD-11).¹ It is defined as having all three core features of PTSD, which are re-experiencing the trauma in the present, avoidance of reminders, and a persistent sense of current threat, plus three further disturbances that run through a person’s whole way of living.

Those three additional features are grouped under the heading “disturbances in self-organisation”:

• Emotional dysregulation. Feelings arrive at overwhelming intensity, or are absent when they might be expected, and settle slowly. Some people swing between the two.
• Negative self-concept. A settled belief in one’s own worthlessness, shamefulness or failure, held not as a passing mood but as a fact about oneself.
• Difficulties in relationships. Trouble feeling close to others, staying in contact, or believing that closeness is safe or available.

The idea did not appear suddenly. Judith Herman described a syndrome in survivors of prolonged, repeated trauma in 1992, arguing that the existing PTSD category did not capture what she was seeing in her clinic.³ A review of the ICD-11 proposals traced almost three decades of evidence building towards a separate category, including the observation that many people carry symptom patterns that PTSD alone does not account for.²

Later work supports the distinction empirically. Studies using latent class and latent profile analysis, which look for naturally occurring groupings in symptom data rather than imposing them, have repeatedly found separable PTSD and complex PTSD profiles in trauma-exposed samples.⁴ One frequently cited analysis also distinguished complex PTSD from borderline personality disorder, two presentations that are often confused with each other.⁵

What this means in practice is that if you have been told your difficulties are “just” PTSD, or that they are a personality problem rather than an injury, the current evidence gives you reasonable grounds to ask for a fuller assessment. The diagnosis matters less than the treatment it points towards, but it does point somewhere different.

What Dissociation Actually Means

Dissociation is one of the most misused words in mental health writing. It is often treated as a synonym for daydreaming, or else for something dramatic and rare. It is neither. A widely used definition describes it as a division of the personality, or of the systems that make up a person’s experience, so that functions which normally work together operate separately instead.⁶

In plain terms: memory, emotion, sensation, identity and awareness usually run as one integrated stream. Dissociation is what happens when that stream splits. You might hold the facts of an event without the feeling. You might have the feeling with no idea where it came from. You might lose the sense that your body belongs to you, or that the room around you is real.

It is important to be clear that dissociation is not, in itself, a malfunction. It develops as protection, and it works. When a situation is frightening and cannot be escaped, stepping away from full awareness reduces unbearable experience to something survivable. The difficulty is that a protection which was necessary then can persist long after the danger has gone, and it is that persistence, rather than the mechanism itself, that becomes the problem.

Researchers distinguish between two broad forms, and the difference matters for what helps:

• Detachment. Depersonalisation, which is the sense of being outside or disconnected from yourself, and derealisation, which is the sense that the world has become unreal, flat, or dreamlike.
• Compartmentalisation. Parts of experience becoming inaccessible: gaps in memory, sensations or movements that cannot be brought under voluntary control, or distinct states of self that hold different memories and reactions.

Both are common after prolonged trauma. Neither means you are losing your mind, and neither means you are beyond help.

Why the Two Travel Together

Complex PTSD arises from trauma that was prolonged, repeated, and difficult to escape. That last part is the key to understanding the dissociation that so often comes with it.

When threat appears, the body has a sequence of defences available to it. Researchers describe this as a defence cascade: first freezing to assess, then flight, then fight, and if none of those can work, a shift into shutdown states in which heart rate drops, movement becomes difficult, and awareness narrows or withdraws.⁷ Dissociation sits at the far end of that sequence. It is the defence that remains when the ones requiring escape or resistance are unavailable.

A child living with ongoing harm in the home, an adult in a coercive relationship, a person in captivity or in care they cannot leave: in each case, running and fighting are ruled out. What remains is the capacity to not be fully present. Used once, that is an emergency measure. Used across years of development, it becomes the nervous system’s default answer to distress.

The theory of structural dissociation describes the longer-term result.⁸ Rather than developing a single, flexible sense of self that can hold both ordinary life and traumatic memory, the personality organises into parts: those oriented towards daily functioning, and those that carry the traumatic material along with the defensive reactions attached to it. The parts stay separate because keeping them separate is what allowed daily life to continue at all. This is a spectrum, not a single condition, and it ranges from mild compartmentalisation through to dissociative identity disorder (DID).

There is neurobiological support for taking dissociation seriously as a distinct presentation. Brain imaging work identified a dissociative subtype of PTSD characterised by emotional overmodulation, in which regulatory regions of the brain dampen limbic activity, rather than the underregulation seen in more familiar hyperarousal.⁹ In other words, two people can both have PTSD while their brains are doing close to opposite things, and treatment that assumes the first pattern may not fit the second.

This is worth holding onto if you have ever been told to calm down when you were already numb, or offered relaxation techniques when what you needed was to come back into the room.

How Dissociation Shows Up in Everyday Life

Many people with complex PTSD do not recognise their own dissociation, because it is the water they have always swum in. These are some of the forms it takes. You do not need all of them, and having several does not indicate severity by itself.

• Time that goes missing. Arriving somewhere with no memory of the journey. Losing an hour, an afternoon, or occasionally longer.
• Watching yourself. A sense of observing your own speech and movement from outside, as though you were a passenger.
• The world going flat. Colours dulled, sounds distant, familiar rooms or faces feeling like stage scenery.
• Emotional numbing. Being unable to feel much of anything, including things you know you care about, often mistaken for not caring.
• Bodily disconnection. Not noticing hunger, cold, pain or injury. Limbs feeling as though they belong to someone else.
• Shifts in state. Moving abruptly between ways of being that feel quite different, with different capacities, preferences or ages to them.
• Fragmented memory. Gaps in autobiographical memory, or memory that arrives as sensation and image rather than as a story with a beginning and end.
• Losing skills. Finding that competences available yesterday, such as driving, reading or conversation, are temporarily out of reach.

People often describe the cost of this in social rather than clinical terms. Relationships strain because you were not fully present for a conversation you are later expected to remember. Work suffers in ways that look like carelessness. And because dissociation is invisible, it tends to be interpreted by others as disinterest, laziness or dishonesty, which adds a layer of shame on top of the original injury.

If you take one thing from this section, let it be this: you were not being difficult. Your nervous system was doing the thing that once kept you safe.

What Treatment Looks Like

There is a persistent myth that dissociation makes trauma therapy impossible, or that people who dissociate must be excluded from it. The evidence does not support that. A meta-analysis examining whether dissociation reduces the effectiveness of psychotherapy for PTSD found that people with higher dissociation benefited from treatment, including trauma-focused treatment, though some analyses suggested slightly smaller gains in certain conditions.¹¹ Dissociation is a reason to adapt the work, not to withhold it.

UK national guidance from the National Institute for Health and Care Excellence (NICE) recommends trauma-focused cognitive behavioural therapy and eye movement desensitisation and reprocessing (EMDR) for post-traumatic stress disorder, with more sessions where the trauma was prolonged or repeated, and attention to stabilisation and emotion regulation where needed.¹²

For complex presentations, most specialist frameworks describe three phases, an idea that goes back to Herman’s original formulation:³

1. Safety and stabilisation. Establishing practical safety, reducing self-harming coping, learning to notice and influence your own arousal, and building skills for staying present. This phase is often the longest, and skipping it is the most common reason trauma work destabilises someone.
2. Processing traumatic memory. Working with the traumatic material itself, at a pace that keeps you within a manageable range of activation, so that memory can begin to be held as past rather than replayed as present.
3. Reintegration and reconnection. Grieving what was lost, rebuilding relationships and identity, and turning towards a life that is organised around something other than survival.

A systematic review and meta-analysis of psychological interventions for ICD-11 complex PTSD symptoms found that a range of approaches produced improvement across symptom clusters, and that interventions including a phase-based element were associated with better outcomes for the disturbances in self-organisation specifically.¹³ Expert guidance for the more marked dissociative disorders describes the same phased approach, with an emphasis on working respectfully with dissociative parts rather than attempting to remove them.¹⁴

Practically, in England you can self-refer to NHS talking therapies without going through a GP, though complex trauma and dissociation may need onward referral to a specialist service. It is entirely reasonable to ask a prospective therapist directly about their training in complex trauma and dissociation before you begin. A good clinician will not be offended by the question.

Practical Steps You Can Begin This Week

Formal treatment takes time to arrange. These are things that can be started without waiting for it. They are not a substitute for therapy, and they are deliberately small.

1. Learn your own early signs

Dissociation rarely arrives without warning, but the warning is usually subtle and easy to miss. For a week, note what happens in the minute or two beforehand. Common early signs include sounds becoming distant, vision narrowing or sharpening oddly, a sense of floating, tingling in the hands or face, sudden heaviness, or the feeling of a sheet of glass sliding into place.

Keep the record extremely short. One line, phone notes, no analysis: “3pm, sounds got far away, was reading emails.” The aim is a list of your personal signals, because intervening early is far easier than coming back from a long way out.

2. Work with the window of tolerance

The window of tolerance describes the band of nervous system arousal in which you can think and feel at the same time.¹⁰ Above it is hyperarousal: panic, rage, racing thoughts, the sense of too much. Below it is hypoarousal: numbness, collapse, emptiness, the sense of nothing. Dissociation is often the exit route from the top of the window straight down through the bottom.

The useful shift is to stop asking “am I calm?” and start asking “where am I in the window, and which direction am I moving?” Upward drift and downward drift need different responses. Soothing a person who is already shut down pushes them further down. Stimulating a person who is already overwhelmed pushes them further up.

3. Match the grounding to the direction

If you are drifting upward into too much:

• Slow the out-breath, letting it be longer than the in-breath, for around ten breaths.
• Press your feet firmly into the floor and feel the resistance.
• Name five things you can see, going slowly enough to actually look at each one.
• Reduce input: step outside, turn the screen off, leave the room.

If you are drifting downward into numbness or unreality:

• Increase gentle movement: stand, walk the length of the room, roll your shoulders, stretch.
• Use a strong but safe sensory input: a cool drink, a strong-smelling herb or spice, running your hands under the tap.
• Speak out loud. Say your name, today’s date, where you are and what you can see. Hearing your own voice is more grounding than thinking the words.
• Orient to the room deliberately: turn your head and look around, letting your eyes rest on each wall in turn.

Practise these when you are reasonably steady, not only in crisis. Skills rehearsed in calm are the ones available under pressure.

4. Build predictability where you can

Dissociation increases with unpredictability, exhaustion and hunger, all of which are easier to influence than the underlying trauma. Regular meals, a consistent sleep window, and a short, unchanging morning sequence do more for dissociation than their simplicity suggests. This is not a lifestyle prescription. It is load reduction.

5. Reduce the cost of lost time

Some practical scaffolding helps while the dissociation is still frequent. Keep one calendar and trust it over your memory. Leave notes for yourself in places you will find them. Set alarms for transitions rather than relying on noticing the time. If a conversation matters, ask for it in writing afterwards. None of this is giving up on your memory. It is removing a source of daily shame while the rest of the work proceeds.

6. Take the pace seriously

There is an understandable wish to get to the traumatic material and have it done with. With dissociation in the picture, going faster usually means going backwards. Approaching memory in small, deliberate portions with returns to the present in between is the approach specialist guidance recommends, and it is the approach that tends to hold.¹⁴ Slower is not a compromise here. It is the method.

A pause before the next section. Notice your breath, without trying to change it. Notice what is holding your weight. You have been reading about difficult things, and the reading is not the same as the thing.

When to Seek Professional Support

Content warning: this section refers briefly to self-harm and suicidal thoughts.

Dissociation itself is common and is not, on its own, a reason for urgent help. These are signs that support beyond self-management would be useful:

• Losing time regularly, or finding evidence of actions you do not remember taking.
• Dissociation that is increasing in frequency, or that is happening while driving, caring for children, or at work in ways that create risk.
• Traumatic memory intruding so often that daily functioning is affected.
• Using alcohol, drugs or self-harm to manage numbness or to feel something.
• Thoughts of ending your life, or of not being here.
• Coming out of dissociation into panic or despair that you cannot bring down.

A GP is a reasonable first step in the UK, and it is worth writing down what you want to say beforehand, because dissociation has a habit of appearing in exactly the appointments where you need words. In England, NHS talking therapies accept self-referral. Charities including Mind can help you understand what is available locally and what to ask for.

If you have been offered therapy that made things worse, that is information rather than failure. It often means the pacing or the approach did not fit a dissociative presentation, and it is worth saying so plainly when you next seek help.

Further Reading

Books: starting out

• Trauma is Really Strange, by Steve Haines, illustrated by Sophie Standing. A short graphic guide that explains trauma and dissociation in pictures. Useful when reading is hard.
• The Body Keeps the Score, by Bessel van der Kolk. The most widely read introduction to trauma’s effects on body and mind. Be aware that some case material is vivid, so read it in portions.
• Healing Trauma, by Peter Levine. A brief, practical introduction to body-based approaches, with exercises.

Books: going deeper

• Coping with Trauma-Related Dissociation, by Suzette Boon, Kathy Steele and Onno van der Hart. A structured skills manual written for people living with dissociation, and widely used alongside therapy. Probably the single most useful book on this page for daily management.
• Healing the Fragmented Selves of Trauma Survivors, by Janina Fisher. A compassionate account of working with dissociative parts. Written for clinicians but readable, and often recommended to clients.
• The Haunted Self, by Onno van der Hart, Ellert Nijenhuis and Kathy Steele. The primary text on structural dissociation theory. Advanced and clinical, for readers who want the underlying model.

Journal articles for the general reader

• Brewin and colleagues (2017), a clear review of the reasoning behind the ICD-11 complex PTSD category. Accessible if you skim the statistics.²
• Karatzias and colleagues (2019), a plain-language abstract summarising what psychological treatments achieve for complex PTSD symptoms.¹³
• Hoeboer and colleagues (2020), open access, on whether dissociation reduces the benefit of trauma therapy. Reassuring reading if you have been told you are not suitable for treatment.¹¹

Support resources

• Mind at mind.org.uk, for plain-English information on dissociation, PTSD and getting help in the UK, plus a support line.
• PTSD UK at ptsduk.org, for UK-specific information on complex PTSD and treatment routes.
• The First Person Plural community at firstpersonplural.org.uk, a UK charity run by and for people with dissociative experiences.

A Last Thought

The thing that is hardest to believe, when dissociation has been your companion for years, is that presence is available to you. Not permanently and not all at once, but in longer and longer stretches. People do get there. The distance closes.

Recovery here does not look like a breakthrough. It looks like noticing you were about to go, and staying. It looks like a whole conversation you remember afterwards. It looks like being cold and putting a jumper on, because you felt it. Those are not modest markers of progress. They are what progress is made of.

Before you close this page, come back to the room you are in. Notice your breath. Notice the surface under your hands. Look at one thing nearby and let your eyes rest on it. Whatever you have been reading about, it is not happening now. You are here, and you got this far.

References

1. World Health Organization. (2019). International classification of diseases for mortality and morbidity statistics (11th revision). https://icd.who.int/browse11
2. Brewin, C. R., Cloitre, M., Hyland, P., Shevlin, M., Maercker, A., Bryant, R. A., Humayun, A., Jones, L. M., Kagee, A., Rousseau, C., Somasundaram, D., Suzuki, Y., Wessely, S., van Ommeren, M., & Reed, G. M. (2017). A review of current evidence regarding the ICD-11 proposals for diagnosing PTSD and complex PTSD. Clinical Psychology Review, 58, 1–15. https://doi.org/10.1016/j.cpr.2017.09.001
3. Herman, J. L. (1992). Complex PTSD: A syndrome in survivors of prolonged and repeated trauma. Journal of Traumatic Stress, 5(3), 377–391. https://doi.org/10.1002/jts.2490050305
4. Karatzias, T., Shevlin, M., Fyvie, C., Hyland, P., Efthymiadou, E., Wilson, D., Roberts, N., Bisson, J. I., Brewin, C. R., & Cloitre, M. (2017). Evidence of distinct profiles of posttraumatic stress disorder (PTSD) and complex posttraumatic stress disorder (CPTSD) based on the new ICD-11 Trauma Questionnaire (ICD-TQ). Journal of Affective Disorders, 207, 181–187. https://doi.org/10.1016/j.jad.2016.09.032
5. Cloitre, M., Garvert, D. W., Weiss, B., Carlson, E. B., & Bryant, R. A. (2014). Distinguishing PTSD, complex PTSD, and borderline personality disorder: A latent class analysis. European Journal of Psychotraumatology, 5, 25097. https://doi.org/10.3402/ejpt.v5.25097
6. Nijenhuis, E. R. S., & van der Hart, O. (2011). Dissociation in trauma: A new definition and comparison with previous formulations. Journal of Trauma & Dissociation, 12(4), 416–445. https://doi.org/10.1080/15299732.2011.570592
7. Schauer, M., & Elbert, T. (2010). Dissociation following traumatic stress: Etiology and treatment. Zeitschrift für Psychologie, 218(2), 109–127. https://doi.org/10.1027/0044-3409/a000018
8. Van der Hart, O., Nijenhuis, E. R. S., & Steele, K. (2006). The haunted self: Structural dissociation and the treatment of chronic traumatization. W. W. Norton.
9. Lanius, R. A., Vermetten, E., Loewenstein, R. J., Brand, B., Schmahl, C., Bremner, J. D., & Spiegel, D. (2010). Emotion modulation in PTSD: Clinical and neurobiological evidence for a dissociative subtype. American Journal of Psychiatry, 167(6), 640–647. https://doi.org/10.1176/appi.ajp.2009.09081168
10. Corrigan, F. M., Fisher, J. J., & Nutt, D. J. (2011). Autonomic dysregulation and the window of tolerance model of the effects of complex emotional trauma. Journal of Psychopharmacology, 25(1), 17–25. https://doi.org/10.1177/0269881109354930
11. Hoeboer, C. M., De Kleine, R. A., Molendijk, M. L., Schoorl, M., Oprel, D. A. C., Mouthaan, J., Van der Does, W., & Van Minnen, A. (2020). Impact of dissociation on the effectiveness of psychotherapy for post-traumatic stress disorder: Meta-analysis. BJPsych Open, 6(3), e53. https://doi.org/10.1192/bjo.2020.30
12. National Institute for Health and Care Excellence. (2018). Post-traumatic stress disorder (NICE guideline NG116). https://www.nice.org.uk/guidance/ng116
13. Karatzias, T., Murphy, P., Cloitre, M., Bisson, J., Roberts, N., Shevlin, M., Hyland, P., Maercker, A., Ben-Ezra, M., Coventry, P., Mason-Roberts, S., Bradley, A., & Hutton, P. (2019). Psychological interventions for ICD-11 complex PTSD symptoms: Systematic review and meta-analysis. Psychological Medicine, 49(11), 1761–1775. https://doi.org/10.1017/S0033291719000436
14. International Society for the Study of Trauma and Dissociation. (2011). Guidelines for treating dissociative identity disorder in adults, third revision. Journal of Trauma & Dissociation, 12(2), 115–187. https://doi.org/10.1080/15299732.2011.537247

How this article was researched: sources were selected from peer-reviewed journals, UK national clinical guidance, and recognised classification systems, with preference given to work published within the last seven years except where a foundational older text is the standard citation for a concept. This article is educational and does not constitute medical advice, diagnosis, or treatment. It will be reviewed annually for continued accuracy.

Frequently Asked Questions

Post Metadata

Focus keyword: complex PTSD and dissociation

Excerpt: Dissociation is the part of complex PTSD that is least often explained and most often misread as not caring. This guide sets out what complex PTSD is under ICD-11, what dissociation actually does at the level of the nervous system, why prolonged inescapable trauma produces both, and what phase-based treatment and daily management look like in practice.

Meta description: A compassionate, evidence-based guide to complex PTSD and dissociation: why the mind steps away from unbearable experience, what treatment involves, and practical grounding you can start this week.

Category: Healing Trauma

Tags: complex PTSD, CPTSD, dissociation, structural dissociation, depersonalisation, derealisation, window of tolerance, grounding techniques, phase-based treatment, emotional dysregulation, trauma recovery, ICD-11, healing trauma

Permalink: /complex-ptsd-and-dissociation/

Suggested featured image: A calm, warm photograph suggesting gradual return to presence, such as late afternoon light moving across a wooden floor beside an open window with a blanket over a chair. Soft, muted palette, no people, nothing depicting distress or confrontation.

Pillar content: No. Substantial supporting article within the Healing Trauma silo, well suited to internal linking with cornerstone content on dissociation, on complex PTSD, and with the articles on emotional abuse recovery, narcissistic abuse recovery, and somatic approaches.