I've been reading about adult assessment and places such as CLASS and some indication on NAS suggests that diagnosis is probably not possible according to DSM or ICD standards if there is no informant.
I have little/no contact with my parents and both did such a poor job at parenting that even if I could get them to come, they'd likely to contribute anything useful (my mother, for example has started claiming that I have psychosis to make people think I am not telling the truth - I have professional validation that I do not).
I have been told that I started speaking early and I know I have some symptoms by history which I overcame in my teenaged years.
The only other documentation I could possibly dig up would be done videos stored in my grandparents' attic, if I could get a player or convert them.
Otherwise, should I just give up on diagnosis?