Dissociation is not always involuntary. It is a psychological defence mechanism, and sometimes it is entered into by volition.
Nobody will be able to enter such a state unless they learned to do it as a child, and as a result of trauma. Those who are able to do it, therefore, are not to be condemned as evil, but understood as damaged or injured.
Catatonia is a different condition.
Here is a comparison for you; a man has a broken leg and has that leg in plaster. Would you rather he stay in that state or get out of it? The answer, of course, is that it is better for most of us to be without a plaster on our leg, but for that person, for a certain time, it is better for him to remain in plaster. And the reason for this is that the plaster provides protection to the bones of the leg, to enable them to heal.
Similarly, dissociation provides protection to the psyche, and enables it to heal. Once a sufficient level of healing is reached, the dissociation will fade away. This is a natural process, and is not to be condemned by those who do not understand it. Just as we allow the leg to heal in its own time, unless we are qualified in psychology, we ought to allow the mind to heal in its own time as well.
I don't disagree, except I do believe catatonic schizophrenia - and many other forms of mental illness - are exactly this sort of thing.
However, that is semantics.
I would also disagree this has to be learned as a child. People will do whatever they can to cope with a horrible situation. In fact, the very form of "disassociation" is extremely wide. By my book anyway.
For instance, people disassociate themselves from their past sins, pushing them aside and forgetting them. They disassociate themselves from friends who caused ill in their lives. They disassociate from old habits. They disassociate people they have to kill in combat in order to feel less like they are killing people like themselves and more like they are killing just "things". They disassociate from family members or friends in a wide variety of ways. If they are victims of some horrible trauma, they can disassociate from that in a wide variety of ways -- even if it was not as they were children. (Though, yes, this is going to be more common with - say - sexually abused children and so forth because, as you say, the coping mechanisms are not there yet.)
But the coping mechanisms are not there for everyone in every situation.
However, by my book all of this is an absurdity. I view the miracles Jesus did as possible for anyone, if they have the faith to do so. But, the weeds of this world cast out by the devil and his angels - anyone who does not know God in their heart - have gone out: proclaiming the utter certainty of the impossibility of cure through faith.
And that, I see as sad, because I see among my own friends grim pronouncements made for them for serious health and mental problems: and they all turn up wrong.
In fact, it is far worse today then it was back in 30-33 AD. There is so much "proof" of the certainty of doom... but it is all lies from the world.
Why did Jesus cry over Lazarus? Because the people were like little children not understanding the power of God who created them and orders their lives.
But that is all another matter: truth is that all such sorrows and horrors are forgotten in the Spirit of Jesus Christ. All of them. Then one knows the everlasting peace and joy in their hearts of God and those old horrors vanish.
There is therefore no reason to disassociate... not by astral travel, not by drunkenness, not by LSD, not by trance, not by travel, not by wealth, not by anything which promises a better life: because the better life - the only life - is in Jesus Christ.
Why is that itself so hard to believe? Again because of all of the lies in the world and all of the liars.
But above all, because people are scared of giving up everything, "everything", their own selves... to be One in Jesus.
But, when they do, they discover they have given up only the bad things, for Jesus told the truth: He is the Life.
PostScript:
I did not condemn the man, btw, I do not condemn people.
I do urge people not to think escape is "out there" or "up there" or "down there".
I can tell them and do tell them when they are on the wrong path. I have that responsibility to do so.
Now, if you do not belief the part about healing, okay, but if you do not believe the last part of what I was saying -- I would like to know why.