Some of the material here deals extensively with the arrival of freedom from the self. For the avoidance of doubt, while there are a very few similarities with the distressing psychological state called ‘depersonalisation’ — which often is linked with derealisation and dis-association — waking up from the dream of being the self is a very different place of being.
Having not knowingly experienced any of the psychological ‘disorders’ mentioned in person, the author can only rely on descriptions given by those who have.
Depersonalisation is something that is often linked to life episodes that cause anxiety, extreme stress or fear. It has also been linked to various forms of abuse, and the use of drugs. Sometimes there is no obvious causal factor. What happens is that the witnessing individual experiences a separation from the self that is experiencing its life.
‘Enlightenment’ is more like a passing back through the self into a place where the need for the separate self is superseded.
So let us contrast and compare.
First, here’s one official (DSM5) definition of depersonalisation:
…Experiences of unreality, detachment, or being an outside observer with respect to one’s thoughts, feelings, sensations, body, or actions (e.g., perceptual alterations, distorted sense of time, unreal or absent self, emotional and/or physical numbing).
DSM5 2013: Code 300.6
The first important point to note is this: depersonalisation is a psychological disorder because it involves the fear of the loss of the sense of personhood. Sufferers lose contact with the sense of reality in their life, they lose their sense of personal involved attached existence. In contrast, in the words of another ‘enlightened’ person:
Enlightenment doesn’t remove the personal sense, the feeling of existing, but this feeling of being, this ‘I AM’ is pure; it is no longer identified with an individual who is confronting other individuals.
José le Roy
Also, depersonalisation is distressing. The loss of connection with self is felt as a loss, as an impairment, as breaking the ability to interact with others. It is a loss of meaning.
In contrast., in enlightenment:
It was all, quite literally, breathtaking. I seemed to have stopped breathing altogether, absorbed in the Given. Here it was, this superb scene, brightly shining in the clear air, alone and unsupported, mysteriously suspended in the void, and (and this was the real miracle, the wonder and delight) utterly free of “me”, unstained by any observer.
Douglas Harding
Finally for now, depersonalisation is separative. There is a sense of ‘...being an outside observer…’. In contrast again, ‘enlightenment’ is unitive not separative:
In reality, it is the old ‘me’ which disappears; the old way of living as a separate individual (my emphasis) and located in time and space.
José le Roy
Depersonalisation and enlightenment really only share one feature: they both concern the relation of the observer and the self. In one instance the distance is increased: in the other, obliterated, with both of them merging into One.
Before enlightenment chop wood and carry water. After enlightenment, chop wood and carry water.”
Wu Li
References for depersonalisation
http://www.sane.org.uk/how_you_can_help/blogging/show_blog/681
https://psychcentral.com/lib/is-depersonalization-disorder-a-form-of-enlightenment/