"Like I'm behind glass, and none of it touches me"
A 25-year-old woman describes a difficult fortnight following a car accident in which she was uninjured but badly shaken. She says: "Since it happened, sometimes I feel like I'm not really me — like I'm watching myself from a step back, going through the motions, not actually inside my own body." She adds: "And the world around me looks strange too, kind of flat and far away, like I'm looking at it through glass or in a dream." When asked to describe the accident itself, she recounts it in a flat, matter-of-fact tone, with none of the visible distress that would be expected: "The car spun twice and hit the barrier. I could have died. I know that. I just don't feel anything when I say it." She is clear throughout that she knows she is still herself and that the world is still real; it is only the feel of both that has changed.
This case works through a connected sequence — each part builds on what came before, leading to an integrated picture.
Identify
Her sense of watching herself from a step back, not feeling inside her own body, is best identified as:
Correct. Detachment from one's own self, with insight retained, is depersonalisation.
Notice that this experience is about her own self and body specifically, and that she knows she is still herself — that combination points to depersonalisation.
Key discriminating feature: The detachment here is directed at her own self and body, and she retains clear insight that she is still herself — the defining pattern of depersonalisation, not a delusional belief.
Identify
Her description of the world looking flat and distant, "like looking through glass," is best identified as:
Correct. A felt change in how the external world appears, with nothing actually different about it, is derealisation.
This experience is about how the surrounding world feels, not about her own self — that shift in focus is what marks it as derealisation rather than depersonalisation.
Key discriminating feature: This time the sense of unreality is directed outward, at the environment, rather than at her own self — the outward-facing counterpart of depersonalisation.
Identify
Her flat, matter-of-fact recounting of a near-fatal accident, without the distress that would normally be expected, is best identified as:
Correct. A selective gap between a specific distressing memory and the feeling that should accompany it is dissociation of affect.
The key is that this flatness is specific to this one memory, not a general reduction in her emotional responsiveness — that selectivity is what makes it dissociation of affect rather than affect blunting.
Key discriminating feature: The emotional response that would be expected for this specific, highly significant memory is missing, while her emotional responsiveness in the rest of the interview is otherwise unremarkable — a selective separation between content and feeling, not a general reduction.
Discriminate
What is the clearest way to keep these three experiences separate when documenting this presentation?
Correct. Identifying the target of the detachment is what keeps these three phenomena properly separated.
Duration, order of onset, and level of fear don't reliably separate these — what each experience is actually about (self, world, or a specific memory) does.
Key discriminating feature: All three share an underlying quality of detachment, but each has a different target: self (depersonalisation), world (derealisation), or a specific emotionally significant memory (dissociation of affect). Asking what the detachment is actually about is the discriminating move.
Common misconception: Because depersonalisation, derealisation, and dissociation of affect often co-occur after a traumatic event and share a family resemblance, they are sometimes lumped together as "dissociation" without distinguishing which specific target — self, world, or memory — each one concerns.
Elicit
Which single question would most efficiently clarify whether she is describing depersonalisation or derealisation at a given moment?
Correct. This question isolates the target of the experience, which is exactly what distinguishes the two.
Timing, fear of "going mad," and head injury history are reasonable background questions, but none of them tells you whether the strangeness is about her self or her surroundings.
Clinical interviewing principle: Since depersonalisation and derealisation frequently co-occur and are described in overlapping language, ask directly whether the felt strangeness is about the self or about the surroundings, rather than relying on the patient's own spontaneous choice of words.
Explain
Why does this presentation involve three separable phenomena rather than one single "dissociative" experience?
Correct. Distinct targets, sharing a family resemblance in quality, is exactly why descriptive precision matters here.
Timing and differing causes aren't the basis for separating these — what distinguishes them is the specific target of the detachment in each case.
Integrate
Weeks later, the same woman reports a new experience: during a work meeting, she suddenly felt that her colleagues' voices sounded distant and tinny, as if coming from behind a wall, though she remained clearly aware it was still her sitting there. Applying the target-based approach this case established, which of the three phenomena does this new experience belong to, and why?
Correct. The strangeness is about the external world, not the self or a memory's emotional charge — exactly the target question this case's approach is built to answer, regardless of which sense is involved.
Stress alone, or the sensory channel involved, don't determine the classification — asking what the strangeness is about (self, world, or a memory) does, and here it's clearly about the external world.
Summary
This case illustrates how a single post-traumatic presentation can carry several related but genuinely distinct phenomena. Depersonalisation, derealisation, and dissociation of affect all share a family resemblance of detachment, but precise descriptive psychopathology asks, for each experience in turn, exactly what it is detachment from: the self, the world, or a specific charged memory.
Finish caseReferences
- Casey, P. & Kelly, B. (2019). Fish's Clinical Psychopathology, 4th ed. Ch. 7, 'Disorders of the Experience of Self'.
- Casey, P. & Kelly, B. (2019). Fish's Clinical Psychopathology, 4th ed. Ch. 6, 'Disorders of Emotion'.