This article is for information only and does not constitute clinical advice, diagnosis, or a substitute for assessment by a qualified professional.

Quick summary: 

• Existential OCD is a form of OCD built around unanswerable questions (“How do I know anything is real?”, “What’s the point if we all die?”), driven by an intolerance of uncertainty rather than by any genuine philosophical crisis.
• Depersonalisation is the felt sense of being detached from yourself; derealisation is the sense that the world around you is unreal. Both are common, usually harmless, and frequently triggered by anxiety.
• The two often travel together, which is why they get confused with each other — and with panic, psychosis, and Depersonalisation–Derealisation Disorder (DPDR).
• The question that changes treatment isn’t “which label?” but “what is the behaviour doing?” Reassurance, research, and reality-checking feel helpful but keep the loop alive.
• Evidence-based treatment (ERP, cognitive work, and grounding used sparingly) targets that loop. You don’t have to answer the question or make the feeling disappear to recover.

 What you won’t find elsewhere

Most articles on this topic simply define the terms and stop. This one adds an original clinical model I use in practice — the certainty loop with two front doors — plus a three-question self-check to spot what’s really driving the distress, an anonymised case example, and a counter-intuitive point that contradicts a lot of well-meaning advice online: the coping moves that feel most sensible (grounding on demand, checking that you’re real, researching your symptoms) are usually the very things keeping you stuck.

Existential OCD & Depersonalisation: When Your Own Mind Feels Unreal

Over the past years of specialist OCD practice, I’ve sat with many people caught between two overlapping terrors: a relentless loop of unanswerable questions about existence, and the eerie sense that they — or the world around them — aren’t quite real. Existential OCD and depersonalisation often arrive together, and the confusion between them is one of the most common reasons even experienced clinicians land on the wrong formulation.

Here’s the short answer before we go deeper. Existential OCD is obsessive-compulsive disorder whose content happens to be philosophical; depersonalisation is a feeling of detachment from yourself, often set off by the anxiety those obsessions generate. They are not the same thing; they can coexist, and — this is the part that matters — you treat both by changing your relationship to the experience, not by solving the question or forcing the feeling away.

What is existential OCD?

Existential OCD is a subtype of OCD in which the obsessions centre on large, unanswerable questions about existence, meaning, reality, and consciousness. The content sounds like philosophy; the mechanism is pure OCD.

You might recognise the themes: the meaning or purpose of life (“What’s the use of doing anything if we all die anyway?”), the reality of existence (“How do I know I’m not in a dream, a coma, or a simulation, and that the people I love are real?”), or personal identity and consciousness (“What makes me me, and are my thoughts really my own?”). Philosophers have chewed on these for millennia and slept fine. In existential OCD, the same questions become sticky, distressing, and impossible to put down.

The engine underneath is not curiosity — it’s an intolerance of uncertainty, a well-documented feature across OCD presentations (Gentes & Ruscio, 2011). The mind treats a question that has no final answer as a problem that must be solved, and then keeps trying to solve it. That drive shows up as mental compulsions: reviewing arguments, seeking reassurance, researching for hours, mentally “checking” whether a thought feels true. Existential rumination isn’t the disorder finding meaning; it’s the disorder chasing certainty it can never catch.

It helps to remember that intrusive thoughts themselves are universal. In a study spanning 13 countries and six continents, 93.6% of people without OCD reported unwanted intrusive thoughts in the previous three months, and doubting intrusions were the single most common category (Radomsky et al., 2014). Having a strange “what if none of this is real?” thought is ordinary. Getting stuck fighting it is what marks OCD.

What is depersonalisation, and how is it different from derealisation?

Depersonalisation is the experience of feeling detached from your own self — your thoughts, feelings, body, or actions feel strange, distant, or not quite yours. Derealisation is the same detachment aimed outward: the world looks flat, dreamlike, foggy, or unreal.

People describe depersonalisation as feeling like a robot, watching themselves from the outside, feeling emotionally numb, or sensing that their memories don’t belong to them. Derealisation sounds more like “everything looks like a film set” or “sounds seem far away.” Crucially, in both, reality testing stays intact — you know these are subjective experiences, not literal facts, which is what separates them from psychosis (American Psychiatric Association, 2013).

These experiences are far more common than most people assume. Around half of people report at least one episode of depersonalisation in their lifetime — the “highway hypnosis” of arriving somewhere with no memory of the drive is a mild, everyday example. They tend to surface during stress, exhaustion, grief, or intense anxiety, and they usually pass. A cognitive-behavioural model of these experiences links them closely to anxiety, with catastrophic misinterpretation (“this means I’m losing my mind”) turning a transient sensation into a self-sustaining problem (Hunter et al., 2003).

Can OCD cause depersonalisation? How existential OCD & Depersonalisation feed each other

Yes — OCD can trigger depersonalisation, and in severe or highly anxious moments this is common rather than unusual. When anxiety spikes, the nervous system can produce that detached, unreal feeling as a kind of overload response.

From there, a vicious circle forms. Anxiety produces depersonalisation; depersonalisation feels alarming, so it produces more anxiety and more obsessive analysis of what the feeling “means.” For someone with existential OCD, that unreal sensation is almost tailor-made to confirm the fear: “See? Maybe nothing IS real.” The bodily experience becomes evidence for the philosophical obsession, and the philosophical obsession amplifies the bodily experience. Each door leads into the same room.

This is exactly why the two get muddled in the clinic. The intrusive question (“Am I real? Is this my voice?”) mirrors a classic OCD obsession, while the compulsions — reassurance-seeking, repeated online searching, questioning loved ones, and avoiding triggering situations — look identical whether the “primary” problem is labelled OCD, anxiety, or a dissociative experience.

Existential OCD and depersonalisation vs Depersonalisation–Derealisation Disorder (DPDR)

The key difference is what the person is fighting. In OCD (including the existential subtype), the distress is driven by an unanswerable question and the compulsive urge to resolve it. In Depersonalisation–Derealisation Disorder, the distress is driven by the perceptual feeling itself and the wish for it to stop.

DPDR is classified as a dissociative disorder — persistent or recurrent detachment that causes significant distress, isn’t due to a substance or medical condition, and isn’t better explained by another disorder (American Psychiatric Association, 2013). It’s under-recognised and often takes years to diagnose correctly. Yet many people with DPDR also show textbook OCD-style behaviour: obsessive analysis of the sensations, compulsive reassurance-seeking, and situational avoidance.

So how do you tell them apart in practice? A few markers help:

• The pull. Existential OCD pulls toward a question you feel you must answer. DPDR pulls toward a feeling you desperately want gone.
• The fear. In OCD-linked panic, the fear is often about physical or catastrophic consequences (“Am I going crazy? Am I losing control?”). In DPDR, the fear is more about living indefinitely in a state of unreality.
• Emotional numbing. Persistent numbness is characteristic of DPDR and comparatively rare in OCD.

None of these has perfectly clean lines, and people frequently meet criteria for more than one thing at once. Which is why, in my experience, chasing the perfect label is the wrong first move.

The certainty loop with two front doors: how I formulate this in practice

This is the original model I use, and it reframes the whole problem: existential OCD and depersonalisation are two entrances to a single maintaining loop, and treatment targets the loop, not the entrance.

Picture one circular loop with two front doors. Door one is an unanswerable question (“How do I know I exist?”). Door two is a bodily feeling of unreality (depersonalisation). Whichever door you come in through, you land in the same corridor: a catastrophic meaning (“something is deeply wrong with me”), followed by a compulsion to fix it (check, research, reassure, avoid, mentally solve), followed by brief relief, followed — reliably — by the feeling or question coming back louder. Every lap sensitises the system, making the next trigger easier to set off.

The clinical punchline is the one the field increasingly emphasises: intervention follows the formulation, not the diagnostic label. If you can see the loop, you can treat it, whether the notes eventually say OCD, DPDR, or both.

The three-question loop check (try this yourself):

1. What am I actually trying to get rid of right now — a question, or a feeling?
2. What do I do to get relief? (Common answers: check, Google, ask for reassurance, avoid, or try to “think my way out.”)
3. Does the relief last — and is the whole thing getting bigger over time?

If your relief is temporary and the problem is growing, you’ve found the loop. That’s good news, because loops are treatable in a way that unanswerable questions are not.

Here’s the counter-intuitive part. Some of the most-recommended coping strategies are, on closer inspection, compulsions in disguise. Grounding exercises done on demand every time the feeling appears, constant reality-checking, obsessive symptom-monitoring, and endlessly exploring “why is this happening to me?” all function as reassurance. They lower distress for a moment and teach your brain that the experience was dangerous enough to need neutralising. Used compulsively, the “cure” becomes fuel.

A clinical example

The following is a composite drawn from common presentations and does not describe any single individual.

A man I’ll call M. came to me after two years of what he called “a philosophy problem I can’t switch off.” It had started during a stressful period with poor sleep, when he suddenly felt, walking through a supermarket, as though he were watching himself from a few feet behind — the classic depersonalisation experience. His mind immediately supplied a meaning: if I feel unreal, maybe nothing is real. From there the questions took over. He spent hours online, asked his wife daily whether she “felt real,” re-watched films about simulated worlds looking for clues, and avoided busy places in case the feeling returned.

By the time we met, M. was convinced he needed to answer the question before he could feel better. Our work went the other way. We mapped his loop, and he could see that every reassurance he gathered brought about twenty minutes of calm before the doubt returned stronger. We reduced the reality-checking and reassurance-seeking (response prevention), used graded exposure to the situations he’d been avoiding, and practised letting the unreal feeling be present without arguing with it. The questions didn’t get answered. They got quieter, because he stopped feeding them.

How is existential OCD & Depersonalisation treated?

The most evidence-based approach is cognitive behavioural therapy built around Exposure and Response Prevention (ERP), tailored to target the compulsions and avoidance rather than the philosophical content. CBT with ERP is the recommended psychological treatment for OCD in the UK (National Institute for Health and Care Excellence, 2005), and a meta-analysis of treatment outcomes found a large pooled effect size for ERP (Hedges’s g = 1.39; Olatunji et al., 2013). That figure describes the size of improvement across studies — not a promise that any individual will respond a set amount, and not a “cure.”

In practice, treatment usually weaves together several strands:

• Psychoeducation. Understanding that reassurance maintains the cycle, and that hypervigilance intensifies unreal feelings, is often the first genuine relief a person gets.
• Response prevention for mental and covert compulsions. This is where much of the change happens — resisting the urge to research, reassure, confess, or mentally solve. Because reassurance is so central here, it’s worth reading a dedicated guide on how to break the reassurance-seeking cycle.
• Exposure. For the existential strand, this can mean deliberately reading philosophy, watching reality-bending films, or sitting with the “what if this isn’t real?” thought without neutralising it. For the depersonalisation strand, it can mean re-entering avoided situations and allowing the sensation to be there.
• Grounding — used sparingly. Grounding and mindfulness are helpful skills, but as ways to relate to experience, not as emergency buttons pressed every time discomfort appears.
• A cognitive-behavioural frame for the unreal feeling itself. Learning to relabel the sensation from “this is dangerous and means I’m broken” to “this is an over-anxious brain doing an ordinary thing” directly targets the catastrophic misinterpretation that keeps depersonalisation going (Hunter et al., 2003, 2005).
• Acceptance-oriented work. Approaches drawn from ACT can help you pursue what matters while symptoms are present, and hold thoughts as thoughts rather than facts to be settled.

Because these obsessions are, at heart, intrusive thoughts amplified by compulsions, it’s also worth understanding. And if you’re not yet sure whether what you’re experiencing is OCD, a dissociative experience, or both, the right next step is a proper assessment rather than self-diagnosis — you can start with how to get a professional OCD assessment.

Key takeaways

• Existential OCD is OCD with philosophical content, driven by intolerance of uncertainty.
• Depersonalisation and derealisation are common, usually anxiety-related feelings of unreality, with reality testing intact.
• They frequently co-occur and reinforce each other, and both are maintained by the same loop of catastrophic meaning, compulsion, and brief relief.
• Treatment (ERP, cognitive work, and grounding used sparingly) targets the loop; you recover by changing your relationship to the experience, not by answering the question or eliminating the feeling.

FAQ

Is depersonalisation a symptom of OCD or a separate disorder? It can be either. Depersonalisation is a symptom that appears in many conditions — anxiety, panic, OCD, PTSD, and depression among them — and can also be the central feature of its own diagnosis, Depersonalisation–Derealisation Disorder. In OCD, it’s usually an anxiety-driven response that then becomes a new thing to obsess about.

Why does everything feel unreal when my OCD flares up? High anxiety can produce feelings of detachment as a kind of overload response. If you then interpret that feeling as dangerous — “I’m losing my mind” — the anxiety climbs and the unreal feeling deepens, which is the loop that keeps it going (Hunter et al., 2003).

How do I stop existential rumination? Not by finding the answer, because the questions are designed to be unanswerable. You stop the rumination by treating it as a compulsion: noticing the urge to mentally solve or research, and deliberately not doing it, so the brain relearns that the question isn’t an emergency. This is best done with structured ERP, ideally with a therapist.

Will grounding techniques cure my depersonalisation? Grounding can be a useful skill, but used compulsively — as something you must do every time the feeling appears — it becomes another form of reassurance that keeps the cycle alive. The aim is to need it less over time, not to rely on it as a rescue.

Can existential OCD and depersonalisation be treated at the same time? Yes. Because both are maintained by the same underlying loop, a single formulation-driven course of CBT with ERP can address the philosophical obsessions and the unreal feelings together, rather than tackling them as two separate projects.

About the author

Federico Ferrarese is a BABCP-accredited Cognitive Behavioural Psychotherapist and BPS Chartered Psychologist specialising in OCD and exposure and response prevention (ERP). He holds an MSc in Applied Neuroscience and works with clients across the UK and internationally in English and Italian. BABCP accreditation number: 00001005090 · Read more on the About page

References:
American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). American Psychiatric Publishing.
Gentes, E. L., & Ruscio, A. M. (2011). A meta-analysis of the relation of intolerance of uncertainty to symptoms of generalized anxiety disorder, major depressive disorder, and obsessive–compulsive disorder. Clinical Psychology Review, 31(6), 923–933. https://doi.org/10.1016/j.cpr.2011.05.001
Hunter, E. C. M., Baker, D., Phillips, M. L., Sierra, M., & David, A. S. (2005). Cognitive-behaviour therapy for depersonalisation disorder: An open study. Behaviour Research and Therapy, 43(9), 1121–1130. https://doi.org/10.1016/j.brat.2004.08.003
Hunter, E. C. M., Phillips, M. L., Chalder, T., Sierra, M., & David, A. S. (2003). Depersonalisation disorder: A cognitive-behavioural conceptualisation. Behaviour Research and Therapy, 41(12), 1451–1467. https://doi.org/10.1016/S0005-7967(03)00066-4
National Institute for Health and Care Excellence. (2005). Obsessive-compulsive disorder and body dysmorphic disorder: Treatment (NICE guideline CG31). https://www.nice.org.uk/guidance/cg31
Olatunji, B. O., Davis, M. L., Powers, M. B., & Smits, J. A. J. (2013). Cognitive-behavioral therapy for obsessive-compulsive disorder: A meta-analysis of treatment outcome and moderators. Journal of Psychiatric Research, 47(1), 33–41. https://doi.org/10.1016/j.jpsychires.2012.08.020
Radomsky, A. S., Alcolado, G. M., Abramowitz, J. S., Alonso, P., Belloch, A., Bouvard, M., Clark, D. A., Coles, M. E., Doron, G., Fernández-Álvarez, H., Garcia-Soriano, G., Ghisi, M., Gomez, B., Inozu, M., Moulding, R., Shams, G., Sica, C., Simos, G., & Wong, W. (2014). Part 1—You can run but you can’t hide: Intrusive thoughts on six continents. Journal of Obsessive-Compulsive and Related Disorders, 3(3), 269–279. https://doi.org/10.1016/j.jocrd.2013.09.002
Sierra, M., & Berrios, G. E. (2000). The Cambridge Depersonalisation Scale: A new instrument for the measurement of depersonalisation. Psychiatry Research, 93(2), 153–164. https://doi.org/10.1016/S0165-1781(00)00100-1