Greetings,
From my understanding, everyone has their own unique case of whatever mentall illness, they are afflicted with. I do not like comparing one to another, resulting in me thinking one is worse off than, the other. Yes, some cases are more severe, and others aren't. Though, with something like mental illness, which can grow worse without proper treatment, and or is very challenging to contain, one's severity could, of course change, down the road.
Have a good one.