It is an unacknowledged truth that subjective self-identity is always and already a psychological artefact that exists upon a sliding scale of graduated pathology. A notionally healthy or well-adjusted individual in comparison to a person experiencing some form of dissociative or discontinuous psychological reality represents a difference in degree but not in kind. That is – the various fragments and properties of a healthy mind are not qualitatively different to those of an unhealthy one, it is much more that they exist in different measures, weights, orientations and symmetries in each instance and that we attribute positive or negative qualities to these as much by choice as by learned bias.
The extent, severity and stage of an illness is measured not so much by difference or distance but by varying degrees of similarity.
In this sense we are each and all as equally capable of any state of mental health or illness, shaped by experience, character and psychological self-influence.
The most significant barrier and boundary to a realisation as to the relativity of mental experience is in this context and itself an existential symptom of the pathology that it seeks to conceptually differentiate itself from.
The difference and distance through which we characterise and differentiate boundaries between psychological balance and mental illness is itself a symptom and causal factor in the ascendancy of pathology in individuals. This is the assertion of an Other (or World as context of difference) by which the nature and sustainable continuity of Self is defined and under any sufficient analysis it becomes clear that this core schism is simultaneously the source of health and of in illness in our minds.
There is a core psychotherapeutic fact regarding the essence of subjective self-identity here.