It's either that they all follow the same source (books, articles, forums, ...whatever) or this MLC thing is a real psychological disorder that must be officially recognized by all therapists and psychiatrists.
I think it is a compound psychological event that is still not properly recognized or thought in psychology. The underlying components are all knows, they have to do with development disruptions in critical times in childhood, which then lead to unhealthy coping mechanisms that prevent repair of adjustment, and over time the way the sufferers cope stops working or actually seems to increase the damage and pain. That is what leads to the "explosion" where they just can't deal with it anymore.
Their behaviour, the disorders, the bad coping we all see, the components are all understood. But it seems the larger patterns are not and this is really a problem. Even if an MLC sufferer goes to a therapist without this bigger picture understanding most will use the wrong paradigms and will NOT realize what is really going on through the distortion.
This is what I have learned through this with my wife. And I have the advantage of involving my sister who is a trained therapist and has known my wife for almost as long as I knew her. So we can throughly see what has changed from what she saw before. And as she does more and more research she is surprised how there is so little literature and almost no training for psychologists that she is finding.
I am encouraging her to maybe start specializing in this. She can help people.