My kids are more ASD rather than ADHD but dietary changes and nutritional supplements and generally treating previously unrecognized health issues did a lot for them. While I was really, really sick, I got asked at times if I was (or accused of being) ASD or ADHD. I have no reason to believe I am either, though if I am feverish, in pain, throwing up, heavily medicated and so forth, my attention span and social skills are definitely impaired. Getting healthier has done a lot for my "social skills" (which I actually have, I just sometimes am too screwed up to effectively execute) and attention span/ability to focus.