I'm curious why people would want to be saddled with a diagnosis. I assume it is the desire for some sort of certainty, which I understand, but seems like such a dangerous game.

I am the opposite -- I actively resist such things. If a professional said I had "XYZ Disorder" I would ask them what objective basis is there for this. If they pointed to the DSM, I would say these are arbitrary labels, mere descriptions of symptoms and behavior, decided on by panels of industry appointed experts. If a diagnosis is to be useful, I think it has to identify cause.

Even a diagnosis of "depression" or "anxiety" is to me completely meaningless. These are symptoms not disorders or diseases. Is it anxiety from trauma or from magnesium deficiency?