Please make that argument! I'd say disorder would refer to something unusual, whereas sense of self is very common among humans across different cultures. Am I misinformed?
It’s not a binary thing, to have or not have a sense of self. It’s the strength of that sensation that matters: can you let go of your own shortsighted selfishness to let something else grow? Unusually strong sense of self has been argued to be a cause of longterm depression. Comparison is the thief of joy after all.
You can grow past having a sense of self and still be depressed.
A closer overly simplified cause for many kinds of long term depression is pessimism and doubt. eg, "It will not work [so no need to consider trying]." It will not work is pessimism and not considering trying is doubt. Another terminology to describe this is learned helplessness.
But depression is far more complicated than just that. There is memory compartmentalization in a handful of types of depression, mostly episodic depression.
Sometimes it can be as subtle as not learning to note when you're having a good time. Someone who is depressed may, for example, have fun at an event, but the next time the same event pops up they may be hesitant to go again, because they didn't record when they were happy.
All of perception comes from noticing patterns. Labeling a thing, eg an apple, initially happens because you've seen multiple apples, or you've had it explained to you, which is using previous patterns (turned into words) you've already learned to manufacture a new pattern. Without pattern matching we wouldn't be able to identify or perceive things.
The mind pattern matches things. It's how we learn. We build abstractions, even when we don't know we're doing it.
The sense of self is an abstraction. Without abstractions we wouldn't be able to perceive anything.
(If you're talking about the sense of self as a negative, I'm going to assume here you're coming from a Theravada Buddhist perspective, but if not, I can adjust teaching/explanation style and terminology accordingly. Just let me know.)
The first fetter https://en.wikipedia.org/wiki/Fetter_(Buddhism)#Lists_of_fet... ie identity view / non-self / anatta, is being able to fully identify all of the details that build the abstraction of self, which can only be done during high levels of mindfulness from deep meditation. You'll find many of the things people attribute to self, are things they have, not things they are. eg, the skills you've learned isn't you. It's the skills you have. Though, can an abstraction really -have- things? (It's a failing of English, as this doesn't translate into English properly.)
So, you go through first path and identify all the things you think you are: body, mind, psychology, cultural beliefs, and so on, examining each thing, recursively breaking those things down, and identifying how they are not you, but how the idea of self is built off of it. Eventually you get to see how your identity isn't you, and the freedom of not identifying with things, as well as the suffering that is caused from identifying with things.
Anyways, you'll not see an arhat or zen master wondering around unable to interpret things. They just have fully mapped out what self is and isn't, as well as the other causes of suffering. They're not brain dead.
So is the sense of self a psychological disorder? Self is a delusion, not an illusion, so no. Sense of self (identity view, that is) just causes unnecessary stress.
Basically allowing societies to function (people assuming roles, shame, and whatever). It should be of no surprise that a damaged sense of self often correlates with poor integration into a society.
If status is not tied to a sense of self then I don't know what is.
You mentioned in another comment that the skills you've learned are not you (roles?). They are just things you have. You've just said that identifying these roles as an abstraction is an essential part of understanding the self.
All of these things increase order in a society, and therefore, survival value. This is what I was responding to.
I didn't say that more of a sense of self, whatever that means, makes more community based cultures.