Disturbance of the Immediate Awareness of Self-Unity

This is a disturbance in the normal, taken-for-granted sense that one is a single, unified person at any given moment. It ranges from a milder form, in which the person feels 'as if' they are two people while still knowing this is not literally true, to a more severe form in which the qualifying 'as if' drops away and the person states, without that reservation, that they are genuinely two people at once.

This has traditionally been framed, following Jaspers, as the second of four fundamental aspects of self-experience: the awareness of being a unity at any given point in time, distinct from continuity of identity over time, which concerns whether one remains the same person across time rather than a single person at any one moment.

Recognition features

A sense of being more than one person at the same moment, most often described as acting or speaking in a way that feels automatic, as though driven by another part of oneself
In its milder, more common form, the person retains the qualifying sense that this is 'as if' they are two people, rather than a literal belief
In its more severe form, the 'as if' quality is lost and the person asserts, without qualification, that they are genuinely two people
May occur in the context of a specific delusion, for example a delusion of demoniac possession, in which the second 'person' is identified with a specific external entity

Eliciting it at interview

Ask whether the person has ever felt as though part of them is acting or speaking automatically, as if driven by someone or something else within them
Establish carefully whether the person retains the 'as if' qualification, or asserts this as a literal, unqualified belief, since this distinguishes the milder from the more severe form
Where a literal belief in being two people is present, explore for an underlying delusional framework, such as a belief in possession, which may be organising the experience

Distinguishing features

Differs from disturbance of self-continuity, which concerns whether the person feels they remain the same person over time, rather than whether they feel unified at a single moment
Differs from a passivity phenomenon, in which specific actions are experienced as controlled by an external power, whereas this concerns feeling like two people rather than one's actions being under outside control
The presence or absence of the qualifying 'as if' is the key distinguishing feature between the milder and more severe forms, and has implications for how much insight is retained

Common misconceptions

That this experience is the same as having genuinely separate, enduring personality states; the disturbance described here is a momentary, immediate sense of duality rather than a lasting alternate identity
That the 'as if' qualification makes the experience trivial or unworthy of note; even the milder form can be distressing and clinically significant

Related phenomena

Disturbance of Awareness of Self-Activity · Disturbance of the Continuity of Self · Experience of Multiple Personalities

Practice this

A woman describes moments where she feels as though she is two people acting at the same time, one part of her speaking automatically as if driven by another part of herself. She is clear, though, that this is only how it feels — she does not actually believe she is literally two separate people. What is this? · A man states, without any qualification and with full conviction, that he is genuinely two separate people who happen to share one body, each with a distinct name, history, and way of speaking. Before revealing the answer: is this best described as disturbance of self-unity? · A patient describes a disturbed sense of who they are. Before revealing the answer, decide what distinguishes a disturbance of the continuity of self from a disturbance of self-unity. · A patient describes something unsettling about the sense that their actions belong to them. Before revealing the answer, decide what distinguishes disturbance of self-unity from a passivity phenomenon. · A patient describes an unusual experience of self. Before revealing the answer, decide what distinguishes the experience of multiple personalities from a disturbance of self-unity. · You suspect a patient may be experiencing disturbance of self-unity. Before revealing the answer, decide how you would assess for it. · Explain why the presence or absence of the qualifying 'as if' matters so much clinically when assessing disturbance of self-unity.

Illustration

A 31-year-old woman describes moments during arguments with her partner when she hears herself saying harsh things in a voice that feels as if it belongs to someone else inside her, adding quickly that she knows perfectly well she is only one person, it just feels, in the moment, as though part of her has taken over.

References

Casey, P. & Kelly, B. (2019). Fish's Clinical Psychopathology, 4th ed. Ch. 7, 'Disorders of the Experience of Self'.