> Why do some people's problems get the validation of the medical system and others don't?
Because there are effective forms of treatment available, but are gated by diagnosis because of $reasons. Validation of the medical system enables one to access those treatments, perhaps most important of which is being able to tell yourself, as well as others, that you're having an actual problem and are not "just lazy" or need to "just get yourself together", etc.
I'm pretty sure that I would get a diagnosis of ADHD, because of my experience (in my youth) with amphetamines. Everyone else would be off their heads and I felt really focused and together (and could sleep!).
Because there are effective forms of treatment available, but are gated by diagnosis because of $reasons. Validation of the medical system enables one to access those treatments, perhaps most important of which is being able to tell yourself, as well as others, that you're having an actual problem and are not "just lazy" or need to "just get yourself together", etc.