technically, it becomes an illness when it interferes with life.
just a note, it's not a self-esteem issue. most of my life i've felt pretty confident in who i am. it's an "other" sort of thing. as my mom was verbally tearing me down, i would silently remind myself that she was just stressed and taking it out on me. most of the things she said were obvious projections (like calling me a snob- she was bullied as a kid). so basically, there is what i see myself as, and how i think others see me. as i've matured, i have been trying to reconcile the two by analyzing what i think, hopefully coming to one realistic "self-identity." i know this must sound horribly lame to you. *shrug*when does it go from 1) yeah, think some positive thoughts to 2) hang out with more positive people to 3) find a support group to 4) get ye to a psychologist/etc stat!
so anyway, there's different levels of severity, and there's different treatments, but i don't really understand where you're going with this. i think some people easily dismiss psychological disorders because there's a strong behavioral component to most of them, most of which seems like common sense, which is something that not all of us are blessed with.
i actually LOL'ed when i realized that asperger sounds like assburger.