>>547685Mental disorder is a result of perturbations in mental processes, which are specific to the individual being affected. Think of it like something going wrong with a car's engine. Certain parts aren't doing what they're expected to do and need to be fixed, and this can start messing with other parts. But the medicalization of mental disorders applies the logic of disease treatment, where you have like a virus that comes into the body and makes it do specific things (causing specific symptoms) and requiring a specific treatment based on the pathogen. But even if two people have mental disorders with the same cause (like they both had the same traumatic expierience), they might respond to it very differently causing different things to go wrong with their mental processes. And of course you can have people with very similar symptoms caused by different things. Most mental disorders are a result of multiple factors too, compounding each other to be more than somebody's mind can handle and still function normally (but that's partly because currently people don't take mental health seriously enough and it usually has to get pretty bad before they get treatment).
Basically, there are certain patterns you can see in people's disorders, but there's a lot of overlap and the disorder is more a matter of some underlying cause of the symptom rather than the particular combination of symptoms a person has. In that way, DSM style diagnosis is more about managing the disorder than trying to address why somebody got like that and improving their life. A lot of this has to do with the fact that in capitalism, mental health services exist to keep you an effective worker and a lot of mental health issues are caused or exacerbated by capitalist conditions (which the medical field is in no position to combat even if it recognizes this).