How we understand and define things definitely changes over the years and is never fully agreed upon. If you want to read/listen to something interesting about how we get those definitions and terms, there is a book about the creation of the DSM in the 5th edition. It does speak plain about anything so maybe be careful about listening to the audio version in public but if you are curious about how these spectrums get defined and changed, check out: The Book of Woe: The DSM and the Unmaking of Psychiatry.


On an interesting note... I work in behavior therapy with individuals of various age ranges who are on the autism spectrum. My YA character, Donny, for this prep would be diagnosed at least on the spectrum in some way but instead, he has a very strong best friend to help him as they get through high school instead.